Fluctuating synaptic conductances recreate in-vivo-like activity (Destexhe et al 2001)

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Accession:8115
This model (and experiments) reported in Destexhe, Rudolh, Fellous, and Sejnowski (2001) support the hypothesis that many of the characteristics of cortical neurons in vivo can be explained by fast glutamatergic and GABAergic conductances varying stochastically. Some of these cortical neuron characteristics of fluctuating synaptic origin are a depolarized membrane potential, the presence of high-amplitude membrane potential fluctuations, a low input resistance and irregular spontaneous firing activity. In addition, the point-conductance model could simulate the enhancement of responsiveness due to background activity. For more information please contact Alain Destexhe. email: Destexhe@iaf.cnrs-gif.fr
Reference:
1 . Destexhe A, Rudolph M, Fellous JM, Sejnowski TJ (2001) Fluctuating synaptic conductances recreate in vivo-like activity in neocortical neurons. Neuroscience 107:13-24 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Synapse;
Brain Region(s)/Organism:
Cell Type(s): Neocortex V1 L6 pyramidal corticothalamic GLU cell; Neocortex V1 L2/6 pyramidal intratelencephalic GLU cell;
Channel(s): I Na,t; I K; I M;
Gap Junctions:
Receptor(s): GabaA; AMPA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Activity Patterns; Simplified Models; Synaptic noise;
Implementer(s): Destexhe, Alain [Destexhe at iaf.cnrs-gif.fr];
Search NeuronDB for information about:  Neocortex V1 L6 pyramidal corticothalamic GLU cell; Neocortex V1 L2/6 pyramidal intratelencephalic GLU cell; GabaA; AMPA; I Na,t; I K; I M;
TITLE Delayer rectifier

COMMENT
-----------------------------------------------------------------------------
	"delayer-rectifier" K current for action potentials
	---------------------------------------------------

  - potassium current, voltage-dependent
  - iterative equations

  Model of IKd for hippocampal pyramidal cells, from
  Traub & Miles, Neuronal Networks of the Hippocampus, Cambridge, 1991

  Added instantaneous conductance

  Written by Alain Destexhe, Laval University, 1996
-----------------------------------------------------------------------------
ENDCOMMENT


INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}

NEURON {
	SUFFIX ikdT
	USEION k READ ek WRITE ik
	RANGE gkbar, g, vtraub
	RANGE n_inf
	RANGE tau_n
	RANGE n_exp
}


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

PARAMETER {
	gkbar	= .005 	(mho/cm2)
	vtraub	= -55	(mV)		: adjusts threshold
	ek	= -90	(mV)
	celsius = 36    (degC)
	dt              (ms)
	v               (mV)
}

STATE {
	n
}

ASSIGNED {
	ik	(mA/cm2)
	n_inf
	tau_n
	n_exp
	tadj
	g	(mho/cm2)	: instantaneous conductance
}


BREAKPOINT {
	SOLVE states
	g  = gkbar * n*n*n*n
	ik  = g * (v - ek)
}


:DERIVATIVE states {
:	evaluate_fct(v)
:	n' = (n_inf - n) / tau_n
:}

PROCEDURE states() {	: exact when v held constant
	evaluate_fct(v)
	n = n + n_exp * (n_inf - n)
}

UNITSOFF
INITIAL {
:
:  Q10 was assumed to be 2.3 for both currents
:
:  original measurements at room temperature

	tadj = 3.0 ^ ((celsius-36)/ 10 )
	evaluate_fct(v)
	n = n_inf
}

PROCEDURE evaluate_fct(v(mV)) { LOCAL a,b,v2

	v2 = v - vtraub : convert to traub convention

	a = 0.032 * (15-v2) / ( exp((15-v2)/5) - 1)
	b = 0.5 * exp((10-v2)/40)

	tau_n = 1 / (a + b) / tadj
	n_inf = a / (a + b)

	n_exp = 1 - exp(-dt/tau_n)
}

UNITSON

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