D2 dopamine receptor modulation of interneuronal activity (Maurice et al. 2004)

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Accession:98005
"... Using a combination of electrophysiological, molecular, and computational approaches, the studies reported here show that D2 dopamine receptor modulation of Na+ currents underlying autonomous spiking contributes to a slowing of discharge rate, such as that seen in vivo. Four lines of evidence support this conclusion. ... Fourth, simulation of cholinergic interneuron pacemaking revealed that a modest increase in the entry of Na+ channels into the slow-inactivated state was sufficient to account for the slowing of pacemaker discharge. These studies establish a cellular mechanism linking dopamine and the reduction in striatal cholinergic interneuron activity seen in the initial stages of associative learning." See paper for more and details.
Reference:
1 . Maurice N, Mercer J, Chan CS, Hernandez-Lopez S, Held J, Tkatch T, Surmeier DJ (2004) D2 dopamine receptor-mediated modulation of voltage-dependent Na+ channels reduces autonomous activity in striatal cholinergic interneurons. J Neurosci 24:10289-301 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell;
Brain Region(s)/Organism:
Cell Type(s): Neostriatum interneuron ACh cell;
Channel(s): I Na,t; I K; I h; I K,Ca; I Sodium; I Calcium; I Potassium;
Gap Junctions:
Receptor(s): D2;
Gene(s): D2 DRD2; HCN1; HCN2;
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Activity Patterns; Action Potentials; Parkinson's;
Implementer(s): Held, Joshua [j-held at northwestern.edu];
Search NeuronDB for information about:  Neostriatum interneuron ACh cell; D2; I Na,t; I K; I h; I K,Ca; I Sodium; I Calcium; I Potassium;
:Migliore file Modify by Maciej Lazarewicz (mailto:mlazarew@gmu.edu) May/16/2001

TITLE Borg-Graham type generic K-AHP channel

: SK for cholinergic interneuron

NEURON {
	SUFFIX sk_ch
	USEION k READ ek WRITE ik
        USEION ca READ cai
        RANGE  gbar,gkahp,ik
        GLOBAL inf,tau
}

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

PARAMETER {
	celsius = 6.3	(degC)
	gbar	= .003 	(mho/cm2)
        n	= 4
        cai	= 50.e-6 (mM)
        a0	= 1.3e13 (/ms-mM-mM-mM-mM)	:b0/(1.4e-4^4)
        b0	= .5e-2  (/ms)			:0.5/(0.100e3)
        v       	 (mV)
        ek      	 (mV)
}

STATE {	w }

ASSIGNED {
	ik 		(mA/cm2)
        gkahp  		(mho/cm2)
        inf
        tau
}

BREAKPOINT {
	SOLVE state METHOD cnexp
	gkahp = gbar*w
	ik = gkahp*(v-ek)
}

INITIAL {
	rate(cai)
	w=inf
}

FUNCTION alp(cai (mM)) {
  alp = a0*cai^n
}

DERIVATIVE state {     : exact when v held constant; integrates over dt step
        rate(cai)
        w' = (inf - w)/tau
}

PROCEDURE rate(cai (mM)) { :callable from hoc
        LOCAL a
        a = alp(cai)
        tau = 1/(a + b0)
        inf = a*tau
}
















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