Conductance based model for short term plasticity at CA3-CA1 synapses (Mukunda & Narayanan 2017)

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Accession:244922
We develop a new biophysically rooted, physiologically constrained conductance-based synaptic model to mechanistically account for short-term facilitation and depression, respectively through residual calcium and transmitter depletion kinetics. The model exhibits different synaptic filtering profiles upon changing certain parameters in the base model. We show degenercy in achieving similar plasticity profiles with different presynaptic parameters. Finally, by virtually knocking out certain conductances, we show the differential contribution of conductances.
Reference:
1 . Mukunda CL, Narayanan R (2017) Degeneracy in the regulation of short-term plasticity and synaptic filtering by presynaptic mechanisms. J Physiol 595:2611-2637 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Synapse;
Brain Region(s)/Organism:
Cell Type(s): Hippocampus CA3 pyramidal GLU cell;
Channel(s): I h; I K; I CAN;
Gap Junctions:
Receptor(s): AMPA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Conductance distributions; Short-term Synaptic Plasticity; Calcium dynamics; Neurotransmitter dynamics;
Implementer(s): Mukunda, Chinmayee L [chinmayeelm at gmail.com];
Search NeuronDB for information about:  Hippocampus CA3 pyramidal GLU cell; AMPA; I K; I h; I CAN;
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MukundaNarayanan2017
data
readme.html
cal2.mod
cal4.mod
can2.mod
ghkampaC.mod
h.mod *
kadist.mod
kdr.mod
minmax.mod
nahh.mod
pulses.mod
stp.mod
BPF.hoc
EPSC_1.txt
mosinit.hoc
plot_ca_data.m
screenshot.png
                            
TITLE n-calcium channel
: n-type calcium channel


UNITS {
	(mA) = (milliamp)
	(mV) = (millivolt)

	FARADAY = 96520 (coul)
	R = 8.3134 (joule/degC)
	KTOMV = .0853 (mV/degC)
}

PARAMETER {
	v (mV)
	celsius 		(degC)
	gcanbar=.0003 (mho/cm2)
	ki=.001 (mM)
	cai=5e-5 (mM)
	cao = 2  (mM)
}


NEURON {
	SUFFIX can
	USEION ca READ cai,cao WRITE ica
        RANGE gcanbar       
        GLOBAL hinf,minf,taum,tauh
}

STATE {
	m h 
}

ASSIGNED {
	ica (mA/cm2)
        gcan  (mho/cm2) 
        minf
        hinf
        taum
        tauh
}

INITIAL {
        rates(v)
        m = minf
        h = hinf
}

BREAKPOINT {
	SOLVE states METHOD cnexp
	gcan = gcanbar*m*m*h*h2(cai)
	ica = gcan*ghk(v,cai,cao)

}

UNITSOFF
FUNCTION h2(cai(mM)) {
	h2 = ki/(ki+cai)
}


FUNCTION ghk(v(mV), ci(mM), co(mM)) (mV) {
        LOCAL nu,f

        f = KTF(celsius)/2
        nu = v/f
        ghk=-f*(1. - (ci/co)*exp(nu))*efun(nu)
}

FUNCTION KTF(celsius (degC)) (mV) {
        KTF = ((25./293.15)*(celsius + 273.15))
}


FUNCTION efun(z) {
	if (fabs(z) < 1e-4) {
		efun = 1 - z/2
	}else{
		efun = z/(exp(z) - 1)
	}
}

FUNCTION alph(v(mV)) {
	TABLE FROM -150 TO 150 WITH 200
	alph = 1.6e-4*exp(-v/48.4)
}

FUNCTION beth(v(mV)) {
        TABLE FROM -150 TO 150 WITH 200
	beth = 1/(exp((-v+39.0)/10.)+1.)
}

FUNCTION alpm(v(mV)) {
	TABLE FROM -150 TO 150 WITH 200
	alpm = 0.1967*(-1.0*v+19.88)/(exp((-1.0*v+19.88)/10.0)-1.0)
}

FUNCTION betm(v(mV)) {
	TABLE FROM -150 TO 150 WITH 200
	betm = 0.046*exp(-v/20.73)
}

UNITSON

DERIVATIVE states {     : exact when v held constant; integrates over dt step
        rates(v)
        m' = (minf - m)/taum
        h' = (hinf - h)/tauh
}

PROCEDURE rates(v (mV)) { :callable from hoc
        LOCAL a
        a = alpm(v)
        taum = 1/(a + betm(v))
        minf = a*taum
        a = alph(v)
        tauh = 1/(a + beth(v))
        hinf = a*tauh
}












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