Location: Bertram, Arnot, Zamponi, 2002 @ a95d0b851e65 / bertram_arnot_zamponi_2002.cellml

Author:
Tessa Paris <tpar054@aucklanduni.ac.nz>
Date:
2010-02-19 14:26:51+13:00
Desc:
Changed the model abstract
Permanent Source URI:
https://staging.physiomeproject.org/workspace/bertram_arnot_zamponi_2002/rawfile/a95d0b851e656802444c4ccd442403c6356ea2e3/bertram_arnot_zamponi_2002.cellml

<?xml version="1.0" encoding="utf-8"?>
<!--
This CellML file was generated on 17/12/2009 at 2:32:27 at p.m. using:

COR (0.9.31.1333)
Copyright 2002-2009 Dr Alan Garny
http://cor.physiol.ox.ac.uk/ - cor@physiol.ox.ac.uk

CellML 1.0 was used to generate this model
http://www.cellml.org/
-->
<model xml:base="file:///C:/Documents%20and%20Settings/tpar054/Desktop/Repository%20models/bertram_arnot_zamponi_2002/bertram_arnot_zamponi_2002_with_postsynaptic.cellml" name="bertram_arnot_zamponi_2002_version01" cmeta:id="bertram_arnot_zamponi_2002_version01" xmlns="http://www.cellml.org/cellml/1.0#" xmlns:cellml="http://www.cellml.org/cellml/1.0#" xmlns:cmeta="http://www.cellml.org/metadata/1.0#">
	<documentation xmlns="http://cellml.org/tmp-documentation">
		<article>
			<articleinfo>
				<title>G-Protein Specificity In Synaptic Signalling</title>
				<author>
					<firstname>Catherine</firstname>
					<surname>Lloyd</surname>
					<affiliation>
						<shortaffil>Bioengineering Institute, University of Auckland</shortaffil>
					</affiliation>
				</author>
			</articleinfo>
			<section id="sec_status">
				<title>Model Status</title>
				<para>
This model was created by James Lawson on 21/05/07 and has been modified by Tessa Paris on 15/12/09. 
				<para>At present, this model is not able to reproduce the results in the publication. The the presynaptic and postsynaptic cell models have been created but the model still does not run correctly.ValidateCellML verifies this model as valid CellML, although a warning is given as there are equations where the dimensions are equivalent but the units are not.
				</para>
				<!--Changes made by James Lawson on 21/05/07: The model has been rebuilt with the reaction components completely removed. kG_minus was altered to follow the rules defined in the paper: kG2_minus = 64 * kG_minus, kG3_minus = kG2_minus. The value used for kG_minus was 0.00025 and corresponded to the beta1-gamma2 G-proten. kG_minus values for other G-proteins are: beta2-gamma2: 0.001, beta3-gamm2: 0.0005, beta4-gamma2: 0.01-->

				</para>
			</section>
			<sect1 id="sec_structure">
				<title>Model Structure</title>
				<para>
				<para>ABSTRACT:
				</para>
Computational modeling is used to investigate the functional impact of G protein-mediated presynaptic autoinhibition on synaptic filtering properties. It is demonstrated that this form of autoinhibition, which is relieved by depolarization, acts as a high-pass filter. This contrasts with vesicle depletion, which acts as a low-pass filter. Model parameters are adjusted to reproduce kinetic slowing data from different Gbetagamma dimeric isoforms, which produce different degrees of slowing. With these sets of parameter values, we demonstrate that the range of frequencies filtered out by the autoinhibition varies greatly depending on the Gbetagamma isoform activated by the autoreceptors. It is shown that G protein autoinhibition can enhance the spatial contrast between a spatially distributed high-frequency signal and surrounding low-frequency noise, providing an alternate mechanism to lateral inhibition. It is also shown that autoinhibition can increase the fidelity of coincidence detection by increasing the signal-to-noise ratio in the postsynaptic cell. The filter cut, the input frequency below which signals are filtered, depends on several biophysical parameters in addition to those related to Gbetagamma binding and unbinding. By varying one such parameter, the rate at which transmitter unbinds from autoreceptors, we show that the filter cut can be adjusted up or down for several of the Gbetagamma isoforms. This allows for great synapse-to-synapse variability in the distinction between signal and noise.  This mathematical model has been translated into a CellML description which can be downloaded in various formats as described in <xref linkend="sec_download_this_model"/>.
</para>
				<para>
The complete original paper reference is cited below:
</para>
				<para>
Role for G Protein G-Beta-Gamma Isoform Specificity in Synaptic Signal Processing: A Computational Study, Richard Bertram, Michelle I. Arnot, and Gerald W. Zamponi, 2002,
            <emphasis>Journal of Neurophysiology</emphasis>
          , 87, 2612-2623. <ulink url="http://www.ncbi.nlm.nih.gov/pubmed/11976397?dopt=Abstract">PubMed ID: 11976397</ulink>
				</para>
				<informalfigure float="0" id="fig_reaction_diagram">
					<mediaobject>
						<imageobject>
							<objectinfo>
								<title>reaction diagram</title>
							</objectinfo>
							<imagedata fileref="bertram_2002.png"/>
						</imageobject>
					</mediaobject>
					<caption>Schematic diagram of the presynaptic model.</caption>
				</informalfigure>
				<para>
G-protein autoinhibitory feedback on the presynaptic terminal acts like a high-pass filter, allowing only high-frequency signals to pass through the to the postsynaptic cell.  Low-frequency signals are effectively filtered out.  Model simulations in this study show how different G-beta-gamma isoforms have different filtering properties.  They also emphasise that the different filtering characteristics associated with a specific G-beta-gamma subunit depend on many biophysical parameters, such as the unbinding rate of a transmitter molecule from the presynaptic autoreceptor.  For example faster unbinding lowers the filter cut while slower unbinding raises it.  This allows for great synapse-tot-synapse variability in the distinction between signal and background noise.
</para>
			</sect1>
		</article>
	</documentation>
	<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
		<rdf:Seq rdf:about="rdf:#8756eb9b-84b8-49c5-b438-0f8deec3c69b">
			<rdf:li rdf:resource="rdf:#681db93f-9191-411b-9900-40c71db5528a"/>
			<rdf:li rdf:resource="rdf:#67c685c9-0897-402a-9a73-5662ea63e0f4"/>
			<rdf:li rdf:resource="rdf:#0212f74d-04ac-42ae-aed8-a116f0be6466"/>
		</rdf:Seq>
		<rdf:Description rdf:about="rdf:#928a8cb3-6102-4665-88c2-87f9749d15fa">
			<dcterms:W3CDTF xmlns:dcterms="http://purl.org/dc/terms/">2002-05-01 00:00</dcterms:W3CDTF>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#306a9a50-191a-4c87-b9ae-9dcc2b5ed669">
			<vCard:Given xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">R</vCard:Given>
			<vCard:Family xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Bertram</vCard:Family>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#2b80306d-cea1-455b-91ed-4eead4b8d6ca">
			<dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/" rdf:resource="rdf:#8756eb9b-84b8-49c5-b438-0f8deec3c69b"/>
			<dc:title xmlns:dc="http://purl.org/dc/elements/1.1/">Role for G protein Gbetagamma isoform specificity in synaptic signal processing: a computational study</dc:title>
			<bqs:volume xmlns:bqs="http://www.cellml.org/bqs/1.0#">87(5)</bqs:volume>
			<bqs:first_page xmlns:bqs="http://www.cellml.org/bqs/1.0#">2612</bqs:first_page>
			<bqs:Journal xmlns:bqs="http://www.cellml.org/bqs/1.0#" rdf:resource="rdf:#a5d628f7-8a37-4720-a9c1-1f70477dc322"/>
			<dcterms:issued xmlns:dcterms="http://purl.org/dc/terms/" rdf:resource="rdf:#928a8cb3-6102-4665-88c2-87f9749d15fa"/>
			<bqs:last_page xmlns:bqs="http://www.cellml.org/bqs/1.0#">2623</bqs:last_page>
		</rdf:Description>
		<rdf:Description rdf:about="#bertram_arnot_zamponi_2002_version01">
			<ns7:simulation xmlns:ns7="http://www.cellml.org/metadata/simulation/1.0#" rdf:resource="rdf:#c4f6cfb2-de39-44cd-b57a-e51d200749be"/>
			<bqs:reference xmlns:bqs="http://www.cellml.org/bqs/1.0#" rdf:resource="rdf:#28432b5b-4650-4f36-bc1d-858b9a7310cc"/>
			<bqs:reference xmlns:bqs="http://www.cellml.org/bqs/1.0#" rdf:parseType="Resource">
				<dc:subject xmlns:dc="http://purl.org/dc/elements/1.1/" rdf:parseType="Resource">
					<bqs:subject_type>keyword</bqs:subject_type>
					<rdf:value>
						<rdf:Bag>
							<rdf:li>signal transduction</rdf:li>
							<rdf:li>synapse</rdf:li>
							<rdf:li>neuron</rdf:li>
							<rdf:li>g-protein</rdf:li>
							<rdf:li>neurobiology</rdf:li>
						</rdf:Bag>
					</rdf:value>
				</dc:subject>
			</bqs:reference>
			<cmeta:comment xmlns:cmeta="http://www.cellml.org/metadata/1.0#" rdf:resource="rdf:#4962d1ce-9575-47f8-807f-bfb989a2f3b8"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#b0f85834-59cb-4617-a128-c8d7fe2c986a">
			<vCard:Given xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">G</vCard:Given>
			<vCard:Family xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Zamponi</vCard:Family>
			<vCard:Other xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">W</vCard:Other>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#fc564800-d9ce-4169-b76a-2e2fb3fd80e1">
			<vCard:Given xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">James</vCard:Given>
			<vCard:Family xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Lawson</vCard:Family>
			<vCard:Other xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Richard</vCard:Other>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#e9205c98-7495-46f2-a79a-0dedf3022a05">
			<vCard:FN xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#5f43cce8-1920-4b0b-8cf9-b052ff065f15">
			<dcterms:W3CDTF xmlns:dcterms="http://purl.org/dc/terms/">2009-05-15T15:11:54+12:00</dcterms:W3CDTF>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#271814fb-46cc-484b-8cac-29a91f17d358">
			<dcterms:W3CDTF xmlns:dcterms="http://purl.org/dc/terms/">2007-05-21T00:00:00+00:00</dcterms:W3CDTF>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#28432b5b-4650-4f36-bc1d-858b9a7310cc">
			<bqs:Pubmed_id xmlns:bqs="http://www.cellml.org/bqs/1.0#">11976397</bqs:Pubmed_id>
			<bqs:JournalArticle xmlns:bqs="http://www.cellml.org/bqs/1.0#" rdf:resource="rdf:#2b80306d-cea1-455b-91ed-4eead4b8d6ca"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#08fe64cb-6884-418a-92c1-b61046c5615b">
			<dcterms:modified xmlns:dcterms="http://purl.org/dc/terms/" rdf:resource="rdf:#5f43cce8-1920-4b0b-8cf9-b052ff065f15"/>
			<rdf:value>Gave channel state probabilities arbitrary values to satisfy requirements for CellML document validity.

Added stimulus protocol, runs at 10Hz
</rdf:value>
			<cmeta:modifier xmlns:cmeta="http://www.cellml.org/metadata/1.0#" rdf:resource="rdf:#7f1c3d21-1e30-4167-ab5b-14c974879212"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#e0e80d69-123d-4279-b437-a8ca9bfe333a">
			<vCard:ORG xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#80dc5fe7-95a4-4075-9ba3-7c328d5ac804"/>
			<vCard:EMAIL xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#733f6044-99b0-46b9-bf2f-408ab9835efc"/>
			<vCard:N xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#fc564800-d9ce-4169-b76a-2e2fb3fd80e1"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#0212f74d-04ac-42ae-aed8-a116f0be6466">
			<rdf:type rdf:resource="http://www.cellml.org/bqs/1.0#Person"/>
			<vCard:N xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#b0f85834-59cb-4617-a128-c8d7fe2c986a"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#a0e55fe6-3165-4478-84c9-53a430744da0">
			<vCard:FN xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">James Lawson</vCard:FN>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#80dc5fe7-95a4-4075-9ba3-7c328d5ac804">
			<vCard:Orgname xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">University of Auckland</vCard:Orgname>
			<vCard:Orgunit xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Bioengineering Institute</vCard:Orgunit>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#67c685c9-0897-402a-9a73-5662ea63e0f4">
			<rdf:type rdf:resource="http://www.cellml.org/bqs/1.0#Person"/>
			<vCard:N xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#25399440-5fbb-4785-b383-00b7d5174cd4"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#bc3261b2-206b-422c-9410-c0585763c4f4">
			<ns7:boundIntervals xmlns:ns7="http://www.cellml.org/metadata/simulation/1.0#" rdf:resource="rdf:#f6612b93-1456-468a-9a87-2dfc6a75e481"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#4962d1ce-9575-47f8-807f-bfb989a2f3b8">
			<dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/" rdf:resource="rdf:#e9205c98-7495-46f2-a79a-0dedf3022a05"/>
			<rdf:value/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#47f7b166-934f-49d5-9448-d4b714f79c91">
			<vCard:Given xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">James</vCard:Given>
			<vCard:Family xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Lawson</vCard:Family>
			<vCard:Other xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Richard</vCard:Other>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#681db93f-9191-411b-9900-40c71db5528a">
			<rdf:type rdf:resource="http://www.cellml.org/bqs/1.0#Person"/>
			<vCard:N xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#306a9a50-191a-4c87-b9ae-9dcc2b5ed669"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#25399440-5fbb-4785-b383-00b7d5174cd4">
			<vCard:Given xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">M</vCard:Given>
			<vCard:Family xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">Arnot</vCard:Family>
			<vCard:Other xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#">I</vCard:Other>
		</rdf:Description>
		<rdf:Description rdf:about="">
			<dc:publisher xmlns:dc="http://purl.org/dc/elements/1.1/"/>
			<cmeta:comment xmlns:cmeta="http://www.cellml.org/metadata/1.0#" rdf:resource="rdf:#422b085f-e3f1-4ede-a99e-b4a422523d18"/>
			<dcterms:created xmlns:dcterms="http://purl.org/dc/terms/" rdf:resource="rdf:#271814fb-46cc-484b-8cac-29a91f17d358"/>
			<dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/" rdf:resource="rdf:#e0e80d69-123d-4279-b437-a8ca9bfe333a"/>
			<cmeta:modification xmlns:cmeta="http://www.cellml.org/metadata/1.0#" rdf:resource="rdf:#08fe64cb-6884-418a-92c1-b61046c5615b"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#7f1c3d21-1e30-4167-ab5b-14c974879212">
			<vCard:N xmlns:vCard="http://www.w3.org/2001/vcard-rdf/3.0#" rdf:resource="rdf:#47f7b166-934f-49d5-9448-d4b714f79c91"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#733f6044-99b0-46b9-bf2f-408ab9835efc">
			<rdf:type rdf:resource="http://imc.org/vCard/3.0#internet"/>
			<rdf:value>j.lawson@auckland.ac.nz</rdf:value>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#a5d628f7-8a37-4720-a9c1-1f70477dc322">
			<dc:title xmlns:dc="http://purl.org/dc/elements/1.1/">Journal of Neurophysiology</dc:title>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#ad946db6-34de-4d24-9d5f-bdfd00e55861">
			<rdf:rest rdf:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#nil"/>
			<rdf:first rdf:resource="rdf:#729e62e8-5746-4b40-aebc-b3cbf44165e7"/>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#648ea5e7-46b9-4609-8761-67dedf661a70">
			<ns7:endingValue xmlns:ns7="http://www.cellml.org/metadata/simulation/1.0#">1000000</ns7:endingValue>
			<ns7:nonstandard-pointDensity xmlns:ns7="http://www.cellml.org/metadata/simulation/1.0#">100000</ns7:nonstandard-pointDensity>
			<ns7:maximumStepSize xmlns:ns7="http://www.cellml.org/metadata/simulation/1.0#">0.1</ns7:maximumStepSize>
		</rdf:Description>
		<rdf:Description rdf:about="rdf:#422b085f-e3f1-4ede-a99e-b4a422523d18">
			<dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/" rdf:resource="rdf:#a0e55fe6-3165-4478-84c9-53a430744da0"/>
			<rdf:value>This model has been rebuilt to remove reaction components. The differential expressions describing Ca++ channel opening in the paper were used.
Errors in the kG_minus values were also adjusted.</rdf:value>
		</rdf:Description>
	</rdf:RDF>   <units xmlns="http://www.cellml.org/cellml/1.0#" name="s">
      <unit units="second"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="ms">
      <unit units="second" prefix="milli"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="mM">
      <unit units="mole" prefix="milli"/>
      <unit units="litre" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uM">
      <unit units="mole" prefix="micro"/>
      <unit units="litre" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uA">
      <unit units="ampere" prefix="micro"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="pS">
      <unit units="siemens" prefix="pico"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="mV">
      <unit units="volt" prefix="milli"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="cm2">
      <unit units="metre" prefix="centi" exponent="2"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="per_cm2">
      <unit units="cm2" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="per_ms">
      <unit units="ms" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uM_per_ms">
      <unit units="uM"/>
      <unit units="ms" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="per_mM_per_ms">
      <unit units="mM" exponent="-1"/>
      <unit units="ms" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="per_mV_per_ms">
      <unit units="mV" exponent="-1"/>
      <unit units="ms" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uM2_per_ms">
      <unit units="uM" exponent="2"/>
      <unit units="ms" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="mV_per_mM">
      <unit units="mV"/>
      <unit units="mM" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uF_per_cm2">
      <unit units="farad" prefix="micro"/>
      <unit units="per_cm2"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uA_per_cm2">
      <unit units="uA"/>
      <unit units="per_cm2"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="pS_per_cm2">
      <unit units="pS"/>
      <unit units="per_cm2"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="mS_per_cm2">
      <unit units="siemens" prefix="milli"/>
      <unit units="per_cm2"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="nm">
      <unit units="metre" prefix="nano"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uM2_nm">
      <unit units="uM" exponent="2"/>
      <unit units="nm"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uM_per_cm2">
      <unit units="uM"/>
      <unit units="per_cm2"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="millijoule_per_mole_kelvin">
      <unit units="joule" prefix="milli"/>
      <unit units="mole" exponent="-1"/>
      <unit units="kelvin" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="coulomb_per_mole">
      <unit units="coulomb"/>
      <unit units="mole" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="uM_per_coulomb">
      <unit units="uM"/>
      <unit units="coulomb" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="um2_per_second">
      <unit units="meter" prefix="micro" exponent="2"/>
      <unit units="second" exponent="-1"/>
   </units>
   <units xmlns="http://www.cellml.org/cellml/1.0#" name="per_um3">
      <unit units="meter" prefix="micro" exponent="-3"/>
   </units>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="environment">
      <variable name="time" units="s" public_interface="out"/>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="membrane">
      <variable name="V" units="mV" initial_value="-65" public_interface="out"/>
      <variable name="R_gas_const" units="millijoule_per_mole_kelvin" initial_value="8314.41" public_interface="out"/>
      <variable name="Temp" units="kelvin" initial_value="310" public_interface="out"/>
      <variable name="F" units="coulomb_per_mole" initial_value="96485" public_interface="out"/>
      <variable name="Cm" units="uF_per_cm2" initial_value="1" public_interface="out"/>
      <variable name="i_app" units="uA_per_cm2" public_interface="in"/>
      <variable name="i_Na" units="uA_per_cm2" public_interface="in"/>
      <variable name="i_K" units="uA_per_cm2" public_interface="in"/>
      <variable name="i_leak" units="uA_per_cm2" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>V</ci>
            </apply>
            <apply>
               <divide/>
               <apply>
                  <minus/>
                  <apply>
                     <minus/>
                     <apply>
                        <plus/>
                        <ci>i_Na</ci>
                        <ci>i_K</ci>
                        <ci>i_leak</ci>
                     </apply>
                     <ci>i_app</ci>
                  </apply>
               </apply>
               <ci>Cm</ci>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="stimulus_protocol">
      <variable name="Istim" units="uA_per_cm2" public_interface="out"/>
      <variable name="IstimStart" units="ms" initial_value="10"/>
      <variable name="IstimEnd" units="ms" initial_value="50000"/>
      <variable name="IstimAmplitude" units="uA_per_cm2" initial_value="40"/>
      <variable name="IstimPeriod" units="ms" initial_value="300"/>
      <variable name="IstimPulseDuration" units="ms" initial_value="1"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>Istim</ci>
            <piecewise>
               <piece>
                  <ci>IstimAmplitude</ci>
                  <apply>
                     <and/>
                     <apply>
                        <geq/>
                        <ci>time</ci>
                        <ci>IstimStart</ci>
                     </apply>
                     <apply>
                        <leq/>
                        <ci>time</ci>
                        <ci>IstimEnd</ci>
                     </apply>
                     <apply>
                        <leq/>
                        <apply>
                           <minus/>
                           <apply>
                              <minus/>
                              <ci>time</ci>
                              <ci>IstimStart</ci>
                           </apply>
                           <apply>
                              <times/>
                              <apply>
                                 <floor/>
                                 <apply>
                                    <divide/>
                                    <apply>
                                       <minus/>
                                       <ci>time</ci>
                                       <ci>IstimStart</ci>
                                    </apply>
                                    <ci>IstimPeriod</ci>
                                 </apply>
                              </apply>
                              <ci>IstimPeriod</ci>
                           </apply>
                        </apply>
                        <ci>IstimPulseDuration</ci>
                     </apply>
                  </apply>
               </piece>
               <otherwise>
                  <cn cellml:units="uA_per_cm2">0</cn>
               </otherwise>
            </piecewise>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="sodium_current">
      <variable name="i_Na" units="uA_per_cm2" public_interface="out"/>
      <variable name="x_infinity" units="dimensionless" public_interface="out"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="V" units="mV" public_interface="in"/>
      <variable name="n" units="dimensionless" public_interface="in"/>
      <variable name="alpha_x" units="dimensionless" public_interface="out"/>
      <variable name="beta_x" units="dimensionless" public_interface="out"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_Na</ci>
            <apply>
               <times/>
               <cn cellml:units="pS_per_cm2">120</cn>
               <apply>
                  <power/>
                  <ci>x_infinity</ci>
                  <cn cellml:units="dimensionless">3</cn>
               </apply>
               <apply>
                  <minus/>
                  <cn cellml:units="dimensionless">1</cn>
                  <ci>n</ci>
               </apply>
               <apply>
                  <minus/>
                  <ci>V</ci>
                  <cn cellml:units="mV">120</cn>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>x_infinity</ci>
            <apply>
               <divide/>
               <ci>alpha_x</ci>
               <apply>
                  <plus/>
                  <ci>alpha_x</ci>
                  <ci>beta_x</ci>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>alpha_x</ci>
            <apply>
               <divide/>
               <apply>
                  <times/>
                  <cn cellml:units="dimensionless">0.2</cn>
                  <apply>
                     <plus/>
                     <ci>V</ci>
                     <cn cellml:units="mV">40</cn>
                  </apply>
               </apply>
               <apply>
                  <minus/>
                  <cn cellml:units="mV">1</cn>
                  <apply>
                     <times/>
                     <cn cellml:units="mV">1</cn>
                     <apply>
                        <exp/>
                        <apply>
                           <divide/>
                           <apply>
                              <minus/>
                              <apply>
                                 <plus/>
                                 <ci>V</ci>
                                 <cn cellml:units="mV">40</cn>
                              </apply>
                           </apply>
                           <cn cellml:units="mV">10</cn>
                        </apply>
                     </apply>
                  </apply>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>beta_x</ci>
            <apply>
               <times/>
               <cn cellml:units="dimensionless">8</cn>
               <apply>
                  <exp/>
                  <apply>
                     <divide/>
                     <cn cellml:units="mV">1</cn>
                     <apply>
                        <minus/>
                        <apply>
                           <plus/>
                           <ci>V</ci>
                           <apply>
                              <divide/>
                              <cn cellml:units="mV">65</cn>
                              <cn cellml:units="dimensionless">18</cn>
                           </apply>
                        </apply>
                     </apply>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="potassium_current">
      <variable name="i_K" units="uA_per_cm2" public_interface="out"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="V" units="mV" public_interface="in"/>
      <variable name="n" units="dimensionless" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_K</ci>
            <apply>
               <divide/>
               <apply>
                  <times/>
                  <cn cellml:units="pS">36</cn>
                  <apply>
                     <power/>
                     <ci>n</ci>
                     <cn cellml:units="dimensionless">4</cn>
                  </apply>
                  <apply>
                     <plus/>
                     <ci>V</ci>
                     <cn cellml:units="mV">77</cn>
                  </apply>
               </apply>
               <cn cellml:units="cm2">1</cn>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="potassium_current_n_gate">
      <variable name="n" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="alpha_n" units="per_ms" public_interface="out"/>
      <variable name="beta_n" units="per_ms" public_interface="out"/>
      <variable name="V" units="mV" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>n</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <times/>
                  <ci>alpha_n</ci>
                  <apply>
                     <minus/>
                     <cn cellml:units="dimensionless">1</cn>
                     <ci>n</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>beta_n</ci>
                  <ci>n</ci>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>alpha_n</ci>
            <apply>
               <divide/>
               <apply>
                  <times/>
                  <cn cellml:units="per_mV_per_ms">0.02</cn>
                  <apply>
                     <plus/>
                     <ci>V</ci>
                     <cn cellml:units="mV">55</cn>
                  </apply>
               </apply>
               <apply>
                  <minus/>
                  <cn cellml:units="dimensionless">1</cn>
                  <apply>
                     <exp/>
                     <apply>
                        <divide/>
                        <apply>
                           <minus/>
                           <apply>
                              <plus/>
                              <ci>V</ci>
                              <cn cellml:units="mV">55</cn>
                           </apply>
                        </apply>
                        <cn cellml:units="mV">10</cn>
                     </apply>
                  </apply>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>beta_n</ci>
            <apply>
               <times/>
               <cn cellml:units="per_ms">0.25</cn>
               <apply>
                  <exp/>
                  <apply>
                     <divide/>
                     <apply>
                        <minus/>
                        <apply>
                           <plus/>
                           <ci>V</ci>
                           <cn cellml:units="mV">65</cn>
                        </apply>
                     </apply>
                     <cn cellml:units="mV">80</cn>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="leak_current">
      <variable name="i_leak" units="uA_per_cm2" public_interface="out"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="V" units="mV" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_leak</ci>
            <apply>
               <times/>
               <cn cellml:units="pS_per_cm2">0.3</cn>
               <apply>
                  <plus/>
                  <ci>V</ci>
                  <cn cellml:units="mV">54</cn>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="transmitter_release">
      <variable name="R" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="kr_plus" units="per_mM_per_ms" initial_value="0.00015"/>
      <variable name="kr_minus" units="per_ms" initial_value="2.5"/>
      <variable name="Ca" units="uM" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="T" units="mM" public_interface="out"/>
      <variable name="T_bar" units="mM" initial_value="4"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>R</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <times/>
                  <ci>kr_plus</ci>
                  <ci>Ca</ci>
                  <apply>
                     <minus/>
                     <cn cellml:units="dimensionless">1</cn>
                     <ci>R</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>kr_minus</ci>
                  <ci>R</ci>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>T</ci>
            <apply>
               <times/>
               <ci>T_bar</ci>
               <ci>R</ci>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="calcium_concentration">
      <variable name="Ca" units="uM" public_interface="out"/>
      <variable name="Ca_ex" units="mM" initial_value="2"/>
      <variable name="Ca_open" units="uM"/>
      <variable name="Dc" units="um2_per_second" initial_value="220"/>
      <variable name="r" units="nm" initial_value="10"/>
      <variable name="sigma" units="uM_per_ms"/>
      <variable name="i_V" units="uA"/>
      <variable name="g_Ca" units="pS" initial_value="1.2"/>
      <variable name="P" units="mV_per_mM" initial_value="6"/>
      <variable name="R_gas_const" units="millijoule_per_mole_kelvin" public_interface="in"/>
      <variable name="F" units="coulomb_per_mole" public_interface="in"/>
      <variable name="Temp" units="kelvin" public_interface="in"/>
      <variable name="V" units="mV" public_interface="in"/>
      <variable name="O" units="dimensionless" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>Ca_open</ci>
            <apply>
               <divide/>
               <ci>sigma</ci>
               <apply>
                  <times/>
                  <cn cellml:units="per_um3">2</cn>
                  <ci>Dc</ci>
                  <ci>r</ci>
                  <pi/>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>sigma</ci>
            <apply>
               <times/>
               <apply>
                  <minus/>
                  <cn cellml:units="uM_per_coulomb">5.182</cn>
               </apply>
               <ci>i_V</ci>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>i_V</ci>
            <apply>
               <divide/>
               <apply>
                  <times/>
                  <apply>
                     <divide/>
                     <apply>
                        <times/>
                        <ci>g_Ca</ci>
                        <ci>P</ci>
                        <cn cellml:units="dimensionless">2</cn>
                        <ci>F</ci>
                        <ci>V</ci>
                     </apply>
                     <apply>
                        <times/>
                        <ci>R_gas_const</ci>
                        <ci>Temp</ci>
                     </apply>
                  </apply>
                  <ci>Ca_ex</ci>
               </apply>
               <apply>
                  <minus/>
                  <cn cellml:units="dimensionless">1</cn>
                  <apply>
                     <exp/>
                     <apply>
                        <divide/>
                        <apply>
                           <times/>
                           <cn cellml:units="dimensionless">2</cn>
                           <ci>F</ci>
                           <ci>V</ci>
                        </apply>
                        <apply>
                           <times/>
                           <ci>R_gas_const</ci>
                           <ci>Temp</ci>
                        </apply>
                     </apply>
                  </apply>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>Ca</ci>
            <apply>
               <plus/>
               <apply>
                  <times/>
                  <ci>O</ci>
                  <ci>Ca_open</ci>
               </apply>
               <cn cellml:units="uM">0.1</cn>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="rate_constants">
      <variable name="alpha" units="per_ms" public_interface="out"/>
      <variable name="alpha_" units="per_ms" public_interface="out"/>
      <variable name="beta" units="per_ms" public_interface="out"/>
      <variable name="beta_" units="per_ms" public_interface="out"/>
      <variable name="kG_plus" units="per_ms" public_interface="out"/>
      <variable name="a" units="dimensionless" initial_value="0"/>
      <variable name="ka_plus" units="per_mM_per_ms" initial_value="0.2"/>
      <variable name="ka_minus" units="per_ms" initial_value="0.0015"/>
      <variable name="V" units="mV" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="kG_minus" units="per_ms" initial_value="0.00025" public_interface="out"/>
      <variable name="kG2_minus" units="per_ms" initial_value="0.016" public_interface="out"/>
      <variable name="kG3_minus" units="per_ms" initial_value="1.024" public_interface="out"/>
      <variable name="T" units="mM" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>alpha</ci>
            <apply>
               <times/>
               <cn cellml:units="per_ms">0.45</cn>
               <apply>
                  <exp/>
                  <apply>
                     <divide/>
                     <ci>V</ci>
                     <cn cellml:units="mV">22</cn>
                  </apply>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>alpha_</ci>
            <apply>
               <divide/>
               <ci>alpha</ci>
               <cn cellml:units="dimensionless">8</cn>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>beta</ci>
            <apply>
               <times/>
               <cn cellml:units="per_ms">0.015</cn>
               <apply>
                  <exp/>
                  <apply>
                     <divide/>
                     <apply>
                        <minus/>
                        <ci>V</ci>
                     </apply>
                     <cn cellml:units="mV">14</cn>
                  </apply>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>beta_</ci>
            <apply>
               <times/>
               <ci>beta</ci>
               <cn cellml:units="dimensionless">8</cn>
            </apply>
         </apply>
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>a</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <times/>
                  <ci>ka_plus</ci>
                  <ci>T</ci>
                  <apply>
                     <minus/>
                     <cn cellml:units="dimensionless">1</cn>
                     <ci>a</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>ka_minus</ci>
                  <ci>a</ci>
               </apply>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>kG_plus</ci>
            <apply>
               <divide/>
               <apply>
                  <times/>
                  <cn cellml:units="per_ms">3</cn>
                  <ci>a</ci>
               </apply>
               <apply>
                  <plus/>
                  <cn cellml:units="dimensionless">680</cn>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">320</cn>
                     <ci>a</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C1">
      <variable name="alpha" units="per_ms" public_interface="in"/>
      <variable name="beta" units="per_ms" public_interface="in"/>
      <variable name="C1" units="dimensionless" initial_value="1" public_interface="out"/>
      <variable name="C2" units="dimensionless" public_interface="in"/>
      <variable name="C_G1" units="dimensionless" public_interface="in"/>
      <variable name="kG_minus" units="per_ms" public_interface="in"/>
      <variable name="kG_plus" units="per_ms" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C1</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <ci>beta</ci>
                     <ci>C2</ci>
                  </apply>
                  <apply>
                     <times/>
                     <ci>kG_minus</ci>
                     <ci>C_G1</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C1</ci>
                  <apply>
                     <plus/>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">4</cn>
                        <ci>alpha</ci>
                     </apply>
                     <ci>kG_plus</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C2">
      <variable name="alpha" units="per_ms" public_interface="in"/>
      <variable name="beta" units="per_ms" public_interface="in"/>
      <variable name="C1" units="dimensionless" public_interface="in"/>
      <variable name="C2" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="C3" units="dimensionless" public_interface="in"/>
      <variable name="C_G2" units="dimensionless" public_interface="in"/>
      <variable name="kG_plus" units="per_ms" public_interface="in"/>
      <variable name="kG2_minus" units="per_ms" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C2</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">4</cn>
                     <ci>alpha</ci>
                     <ci>C1</ci>
                  </apply>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">2</cn>
                     <ci>beta</ci>
                     <ci>C3</ci>
                  </apply>
                  <apply>
                     <times/>
                     <ci>kG2_minus</ci>
                     <ci>C_G2</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C2</ci>
                  <apply>
                     <plus/>
                     <ci>beta</ci>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">3</cn>
                        <ci>alpha</ci>
                     </apply>
                     <ci>kG_plus</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C3">
      <variable name="alpha" units="per_ms" public_interface="in"/>
      <variable name="beta" units="per_ms" public_interface="in"/>
      <variable name="C2" units="dimensionless" public_interface="in"/>
      <variable name="C3" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="C4" units="dimensionless" public_interface="in"/>
      <variable name="C_G3" units="dimensionless" public_interface="in"/>
      <variable name="kG_plus" units="per_ms" public_interface="in"/>
      <variable name="kG3_minus" units="per_ms" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C3</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">3</cn>
                     <ci>alpha</ci>
                     <ci>C2</ci>
                  </apply>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">3</cn>
                     <ci>beta</ci>
                     <ci>C4</ci>
                  </apply>
                  <apply>
                     <times/>
                     <ci>kG3_minus</ci>
                     <ci>C_G3</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C3</ci>
                  <apply>
                     <plus/>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">2</cn>
                        <ci>beta</ci>
                     </apply>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">2</cn>
                        <ci>alpha</ci>
                     </apply>
                     <ci>kG_plus</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C4">
      <variable name="alpha" units="per_ms" public_interface="in"/>
      <variable name="beta" units="per_ms" public_interface="in"/>
      <variable name="C3" units="dimensionless" public_interface="in"/>
      <variable name="C4" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="O" units="dimensionless" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C4</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">2</cn>
                     <ci>alpha</ci>
                     <ci>C3</ci>
                  </apply>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">4</cn>
                     <ci>beta</ci>
                     <ci>O</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C4</ci>
                  <apply>
                     <plus/>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">3</cn>
                        <ci>beta</ci>
                     </apply>
                     <ci>alpha</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="O">
      <variable name="C1" units="dimensionless" public_interface="in"/>
      <variable name="C2" units="dimensionless" public_interface="in"/>
      <variable name="C3" units="dimensionless" public_interface="in"/>
      <variable name="C4" units="dimensionless" public_interface="in"/>
      <variable name="O" units="dimensionless" public_interface="out"/>
      <variable name="C_G1" units="dimensionless" public_interface="in"/>
      <variable name="C_G2" units="dimensionless" public_interface="in"/>
      <variable name="C_G3" units="dimensionless" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="C_G" units="dimensionless"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>O</ci>
            <apply>
               <minus/>
               <apply>
                  <minus/>
                  <apply>
                     <minus/>
                     <apply>
                        <minus/>
                        <apply>
                           <minus/>
                           <apply>
                              <minus/>
                              <apply>
                                 <minus/>
                                 <cn cellml:units="dimensionless">1</cn>
                                 <ci>C1</ci>
                              </apply>
                              <ci>C2</ci>
                           </apply>
                           <ci>C3</ci>
                        </apply>
                        <ci>C4</ci>
                     </apply>
                     <ci>C_G1</ci>
                  </apply>
                  <ci>C_G2</ci>
               </apply>
               <ci>C_G3</ci>
            </apply>
         </apply>
         <apply>
            <eq/>
            <ci>C_G</ci>
            <apply>
               <plus/>
               <ci>C_G1</ci>
               <ci>C_G2</ci>
               <ci>C_G3</ci>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C_G1">
      <variable name="alpha_" units="per_ms" public_interface="in"/>
      <variable name="beta_" units="per_ms" public_interface="in"/>
      <variable name="C1" units="dimensionless" public_interface="in"/>
      <variable name="C_G1" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="C_G2" units="dimensionless" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="kG_plus" units="per_ms" public_interface="in"/>
      <variable name="kG_minus" units="per_ms" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C_G1</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <ci>beta_</ci>
                     <ci>C_G2</ci>
                  </apply>
                  <apply>
                     <times/>
                     <ci>kG_plus</ci>
                     <ci>C1</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C_G1</ci>
                  <apply>
                     <plus/>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">4</cn>
                        <ci>alpha_</ci>
                     </apply>
                     <ci>kG_minus</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C_G2">
      <variable name="alpha_" units="per_ms" public_interface="in"/>
      <variable name="beta_" units="per_ms" public_interface="in"/>
      <variable name="C2" units="dimensionless" public_interface="in"/>
      <variable name="C_G1" units="dimensionless" public_interface="in"/>
      <variable name="C_G2" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="C_G3" units="dimensionless" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="kG_plus" units="per_ms" public_interface="in"/>
      <variable name="kG2_minus" units="per_ms" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C_G2</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">4</cn>
                     <ci>alpha_</ci>
                     <ci>C_G1</ci>
                  </apply>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">2</cn>
                     <ci>beta_</ci>
                     <ci>C_G3</ci>
                  </apply>
                  <apply>
                     <times/>
                     <ci>kG_plus</ci>
                     <ci>C2</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C_G2</ci>
                  <apply>
                     <plus/>
                     <ci>beta_</ci>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">3</cn>
                        <ci>alpha_</ci>
                     </apply>
                     <ci>kG2_minus</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="C_G3">
      <variable name="alpha_" units="per_ms" public_interface="in"/>
      <variable name="beta_" units="per_ms" public_interface="in"/>
      <variable name="C3" units="dimensionless" public_interface="in"/>
      <variable name="C_G2" units="dimensionless" public_interface="in"/>
      <variable name="C_G3" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="kG_plus" units="per_ms" public_interface="in"/>
      <variable name="kG3_minus" units="per_ms" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>C_G3</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <plus/>
                  <apply>
                     <times/>
                     <cn cellml:units="dimensionless">3</cn>
                     <ci>alpha_</ci>
                     <ci>C_G2</ci>
                  </apply>
                  <apply>
                     <times/>
                     <ci>kG_plus</ci>
                     <ci>C3</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>C_G3</ci>
                  <apply>
                     <plus/>
                     <apply>
                        <times/>
                        <cn cellml:units="dimensionless">2</cn>
                        <ci>beta_</ci>
                     </apply>
                     <ci>kG3_minus</ci>
                  </apply>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="membrane_post">
      <variable name="V_post" units="mV" initial_value="-65" public_interface="out"/>
      <variable name="Cm" units="uF_per_cm2" public_interface="in"/>
      <variable name="i_syn" units="uA_per_cm2" public_interface="in"/>
      <variable name="i_Na_post" units="uA_per_cm2" public_interface="in"/>
      <variable name="i_K_post" units="uA_per_cm2" public_interface="in"/>
      <variable name="i_leak_post" units="uA_per_cm2" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>V_post</ci>
            </apply>
            <apply>
               <divide/>
               <apply>
                  <minus/>
                  <apply>
                     <plus/>
                     <ci>i_Na_post</ci>
                     <ci>i_K_post</ci>
                     <ci>i_leak_post</ci>
                     <ci>i_syn</ci>
                  </apply>
               </apply>
               <ci>Cm</ci>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="synaptic_current">
      <variable name="i_syn" units="uA_per_cm2" public_interface="out"/>
      <variable name="g_syn" units="mS_per_cm2" initial_value="0.2"/>
      <variable name="V_post" units="mV" public_interface="in"/>
      <variable name="V_syn" units="mV" initial_value="0"/>
      <variable name="b" units="dimensionless" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_syn</ci>
            <apply>
               <times/>
               <ci>g_syn</ci>
               <ci>b</ci>
               <apply>
                  <minus/>
                  <ci>V_post</ci>
                  <ci>V_syn</ci>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="leak_current_post">
      <variable name="i_leak_post" units="uA_per_cm2" public_interface="out"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="V_post" units="mV" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_leak_post</ci>
            <apply>
               <times/>
               <cn cellml:units="pS_per_cm2">0.3</cn>
               <apply>
                  <plus/>
                  <ci>V_post</ci>
                  <cn cellml:units="mV">54</cn>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="sodium_current_post">
      <variable name="i_Na_post" units="uA_per_cm2" public_interface="out"/>
      <variable name="x_infinity" units="dimensionless" public_interface="in"/>
      <variable name="V_post" units="mV" public_interface="in"/>
      <variable name="n_post" units="dimensionless" public_interface="in"/>
      <variable name="alpha_x" units="dimensionless" public_interface="in"/>
      <variable name="beta_x" units="dimensionless" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_Na_post</ci>
            <apply>
               <times/>
               <cn cellml:units="pS_per_cm2">120</cn>
               <apply>
                  <power/>
                  <ci>x_infinity</ci>
                  <cn cellml:units="dimensionless">3</cn>
               </apply>
               <apply>
                  <minus/>
                  <cn cellml:units="dimensionless">1</cn>
                  <ci>n_post</ci>
               </apply>
               <apply>
                  <minus/>
                  <ci>V_post</ci>
                  <cn cellml:units="mV">120</cn>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="potassium_current_post">
      <variable name="i_K_post" units="uA_per_cm2" public_interface="out"/>
      <variable name="V_post" units="mV" public_interface="in"/>
      <variable name="n_post" units="dimensionless" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <ci>i_K_post</ci>
            <apply>
               <times/>
               <cn cellml:units="pS_per_cm2">36</cn>
               <apply>
                  <power/>
                  <ci>n_post</ci>
                  <cn cellml:units="dimensionless">4</cn>
               </apply>
               <apply>
                  <plus/>
                  <ci>V_post</ci>
                  <cn cellml:units="mV">77</cn>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="potassium_current_n_gate_post">
      <variable name="n_post" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="alpha_n" units="per_ms" public_interface="in"/>
      <variable name="beta_n" units="per_ms" public_interface="in"/>
      <variable name="time" units="s" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>n_post</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <times/>
                  <ci>alpha_n</ci>
                  <apply>
                     <minus/>
                     <cn cellml:units="dimensionless">1</cn>
                     <ci>n_post</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>beta_n</ci>
                  <ci>n_post</ci>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <component xmlns="http://www.cellml.org/cellml/1.0#" name="bound_postsynaptic_receptors">
      <variable name="b" units="dimensionless" initial_value="0" public_interface="out"/>
      <variable name="time" units="s" public_interface="in"/>
      <variable name="k_b_plus" units="per_mM_per_ms" initial_value="2"/>
      <variable name="k_b_minus" units="per_ms" initial_value="1"/>
      <variable name="T" units="mM" public_interface="in"/>
      <math xmlns="http://www.w3.org/1998/Math/MathML">
         <apply>
            <eq/>
            <apply>
               <diff/>
               <bvar>
                  <ci>time</ci>
               </bvar>
               <ci>b</ci>
            </apply>
            <apply>
               <minus/>
               <apply>
                  <times/>
                  <ci>k_b_plus</ci>
                  <ci>T</ci>
                  <apply>
                     <minus/>
                     <cn cellml:units="dimensionless">1</cn>
                     <ci>b</ci>
                  </apply>
               </apply>
               <apply>
                  <times/>
                  <ci>k_b_minus</ci>
                  <ci>b</ci>
               </apply>
            </apply>
         </apply>
      </math>
   </component>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="membrane"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="sodium_current"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="potassium_current"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="potassium_current_n_gate"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="leak_current"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="transmitter_release"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="calcium_concentration"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="rate_constants"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C1"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C2"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C3"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C4"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="O"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C_G1"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C_G2"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="C_G3"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="membrane_post"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="potassium_current_n_gate_post"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="bound_postsynaptic_receptors"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="leak_current_post"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="sodium_current"/>
      <map_variables variable_1="V" variable_2="V"/>
      <map_variables variable_1="i_Na" variable_2="i_Na"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="potassium_current"/>
      <map_variables variable_1="V" variable_2="V"/>
      <map_variables variable_1="i_K" variable_2="i_K"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="potassium_current_n_gate"/>
      <map_variables variable_1="V" variable_2="V"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="potassium_current" component_2="potassium_current_n_gate"/>
      <map_variables variable_1="n" variable_2="n"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="sodium_current" component_2="potassium_current_n_gate"/>
      <map_variables variable_1="n" variable_2="n"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="leak_current"/>
      <map_variables variable_1="V" variable_2="V"/>
      <map_variables variable_1="i_leak" variable_2="i_leak"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="calcium_concentration"/>
      <map_variables variable_1="V" variable_2="V"/>
      <map_variables variable_1="R_gas_const" variable_2="R_gas_const"/>
      <map_variables variable_1="F" variable_2="F"/>
      <map_variables variable_1="Temp" variable_2="Temp"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="rate_constants"/>
      <map_variables variable_1="V" variable_2="V"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="O" component_2="calcium_concentration"/>
      <map_variables variable_1="O" variable_2="O"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="transmitter_release" component_2="calcium_concentration"/>
      <map_variables variable_1="Ca" variable_2="Ca"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="transmitter_release" component_2="rate_constants"/>
      <map_variables variable_1="T" variable_2="T"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C1"/>
      <map_variables variable_1="alpha" variable_2="alpha"/>
      <map_variables variable_1="beta" variable_2="beta"/>
      <map_variables variable_1="kG_plus" variable_2="kG_plus"/>
      <map_variables variable_1="kG_minus" variable_2="kG_minus"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C2" component_2="C1"/>
      <map_variables variable_1="C2" variable_2="C2"/>
      <map_variables variable_1="C1" variable_2="C1"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G1" component_2="C1"/>
      <map_variables variable_1="C_G1" variable_2="C_G1"/>
      <map_variables variable_1="C1" variable_2="C1"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C2"/>
      <map_variables variable_1="alpha" variable_2="alpha"/>
      <map_variables variable_1="beta" variable_2="beta"/>
      <map_variables variable_1="kG_plus" variable_2="kG_plus"/>
      <map_variables variable_1="kG2_minus" variable_2="kG2_minus"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C3" component_2="C2"/>
      <map_variables variable_1="C3" variable_2="C3"/>
      <map_variables variable_1="C2" variable_2="C2"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G2" component_2="C2"/>
      <map_variables variable_1="C_G2" variable_2="C_G2"/>
      <map_variables variable_1="C2" variable_2="C2"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C3"/>
      <map_variables variable_1="alpha" variable_2="alpha"/>
      <map_variables variable_1="beta" variable_2="beta"/>
      <map_variables variable_1="kG_plus" variable_2="kG_plus"/>
      <map_variables variable_1="kG3_minus" variable_2="kG3_minus"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C4" component_2="C3"/>
      <map_variables variable_1="C4" variable_2="C4"/>
      <map_variables variable_1="C3" variable_2="C3"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G3" component_2="C3"/>
      <map_variables variable_1="C_G3" variable_2="C_G3"/>
      <map_variables variable_1="C3" variable_2="C3"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C4"/>
      <map_variables variable_1="alpha" variable_2="alpha"/>
      <map_variables variable_1="beta" variable_2="beta"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="O" component_2="C4"/>
      <map_variables variable_1="O" variable_2="O"/>
      <map_variables variable_1="C4" variable_2="C4"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C1" component_2="O"/>
      <map_variables variable_1="C1" variable_2="C1"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C2" component_2="O"/>
      <map_variables variable_1="C2" variable_2="C2"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C3" component_2="O"/>
      <map_variables variable_1="C3" variable_2="C3"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G1" component_2="O"/>
      <map_variables variable_1="C_G1" variable_2="C_G1"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G2" component_2="O"/>
      <map_variables variable_1="C_G2" variable_2="C_G2"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G3" component_2="O"/>
      <map_variables variable_1="C_G3" variable_2="C_G3"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C_G1"/>
      <map_variables variable_1="alpha_" variable_2="alpha_"/>
      <map_variables variable_1="beta_" variable_2="beta_"/>
      <map_variables variable_1="kG_plus" variable_2="kG_plus"/>
      <map_variables variable_1="kG_minus" variable_2="kG_minus"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G2" component_2="C_G1"/>
      <map_variables variable_1="C_G2" variable_2="C_G2"/>
      <map_variables variable_1="C_G1" variable_2="C_G1"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C_G2"/>
      <map_variables variable_1="alpha_" variable_2="alpha_"/>
      <map_variables variable_1="beta_" variable_2="beta_"/>
      <map_variables variable_1="kG_plus" variable_2="kG_plus"/>
      <map_variables variable_1="kG2_minus" variable_2="kG2_minus"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="C_G3" component_2="C_G2"/>
      <map_variables variable_1="C_G3" variable_2="C_G3"/>
      <map_variables variable_1="C_G2" variable_2="C_G2"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="rate_constants" component_2="C_G3"/>
      <map_variables variable_1="alpha_" variable_2="alpha_"/>
      <map_variables variable_1="beta_" variable_2="beta_"/>
      <map_variables variable_1="kG_plus" variable_2="kG_plus"/>
      <map_variables variable_1="kG3_minus" variable_2="kG3_minus"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="environment" component_2="stimulus_protocol"/>
      <map_variables variable_1="time" variable_2="time"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="stimulus_protocol"/>
      <map_variables variable_1="i_app" variable_2="Istim"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane" component_2="membrane_post"/>
      <map_variables variable_1="Cm" variable_2="Cm"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane_post" component_2="synaptic_current"/>
      <map_variables variable_1="i_syn" variable_2="i_syn"/>
      <map_variables variable_1="V_post" variable_2="V_post"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane_post" component_2="sodium_current_post"/>
      <map_variables variable_1="V_post" variable_2="V_post"/>
      <map_variables variable_1="i_Na_post" variable_2="i_Na_post"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane_post" component_2="potassium_current_post"/>
      <map_variables variable_1="i_K_post" variable_2="i_K_post"/>
      <map_variables variable_1="V_post" variable_2="V_post"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="membrane_post" component_2="leak_current_post"/>
      <map_variables variable_1="i_leak_post" variable_2="i_leak_post"/>
      <map_variables variable_1="V_post" variable_2="V_post"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="sodium_current_post" component_2="sodium_current"/>
      <map_variables variable_1="x_infinity" variable_2="x_infinity"/>
      <map_variables variable_1="alpha_x" variable_2="alpha_x"/>
      <map_variables variable_1="beta_x" variable_2="beta_x"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="potassium_current_n_gate" component_2="potassium_current_n_gate_post"/>
      <map_variables variable_1="alpha_n" variable_2="alpha_n"/>
      <map_variables variable_1="beta_n" variable_2="beta_n"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="potassium_current_n_gate_post" component_2="sodium_current_post"/>
      <map_variables variable_1="n_post" variable_2="n_post"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="potassium_current_n_gate_post" component_2="potassium_current_post"/>
      <map_variables variable_1="n_post" variable_2="n_post"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="bound_postsynaptic_receptors" component_2="synaptic_current"/>
      <map_variables variable_1="b" variable_2="b"/>
   </connection>
   <connection xmlns="http://www.cellml.org/cellml/1.0#">
      <map_components component_1="bound_postsynaptic_receptors" component_2="transmitter_release"/>
      <map_variables variable_1="T" variable_2="T"/>
   </connection>
</model>