LTP in cerebellar mossy fiber-granule cell synapses (Saftenku 2002)

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Accession:51196
We simulated synaptic transmission and modified a simple model of long-term potentiation (LTP) and long-term depression (LTD) in order to describe long-term plasticity related changes in cerebellar mossy fiber-granule cell synapses. In our model, protein autophosphorylation, leading to the maintenance of long-term plasticity, is controlled by Ca2+ entry through the NMDA receptor channels. The observed nonlinearity in the development of long-term changes of EPSP in granule cells is explained by the difference in the rate constants of two independent autocatalytic processes.
Reference:
1 . Saftenku EE (2002) A simplified model of long-term plasticity in cerebellar mossy fiber-granule cell synapses. Neurophysiology/Neirofiziologiya 34:216-218
Model Information (Click on a link to find other models with that property)
Model Type: Synapse;
Brain Region(s)/Organism:
Cell Type(s):
Channel(s):
Gap Junctions:
Receptor(s): AMPA; NMDA;
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Simplified Models; Long-term Synaptic Plasticity; Maintenance;
Implementer(s): Saftenku, Elena [esaft at biph.kiev.ua];
Search NeuronDB for information about:  AMPA; NMDA;
TITLE Cerebellum Granule Cell Model, Na resurgent channel

COMMENT	  
Reference: E.D'Angelo, T.Nieus, A. Maffei, S. Armano, P. Rossi,
V. Taglietti, A. Fontana, G. Naldi "Theta-frequency bursting and 
resonance in cerebellar granule cells: experimental evidence and 
modeling of a slow K+-dependent mechanism", J. neurosci., 2001,
21,P. 759-770.
ENDCOMMENT
 
NEURON { 
	SUFFIX GrG_Nar
	USEION na READ ena WRITE ina 
	RANGE gnabar, ina, g
	RANGE Aalpha_s,Abeta_s,V0alpha_s,V0beta_s,Kalpha_s,Kbeta_s 
      RANGE Shiftalpha_s,Shiftbeta_s,tau_s,s_inf
	RANGE Aalpha_f,Abeta_f,V0alpha_f,V0beta_f,Kalpha_f, Kbeta_f
	RANGE tau_f,f_inf
} 
 
UNITS {    
	(mA) = (milliamp) 
	(mV) = (millivolt) 
} 
 
PARAMETER { 
	
	: s-ALFA
	Aalpha_s = -0.00493 (/ms)
	V0alpha_s = -4.48754 (mV)
	Kalpha_s = -6.81881 (mV)
	Shiftalpha_s = 0.00008 (/ms)

	: s-BETA
	Abeta_s = 0.01558 (/ms)
	V0beta_s = 43.97494 (mV)
	Kbeta_s =  0.10818 (mV)
	Shiftbeta_s = 0.04752 (/ms)

	: f-ALFA
	Aalpha_f = 0.31836 (/ms)
	V0alpha_f = -80 (mV)
	Kalpha_f = -62.52621 (mV)

	: f-BETA
	Abeta_f = 0.01014 (/ms)
	V0beta_f = -83.3332 (mV)
	Kbeta_f = 16.05379 (mV)

	gnabar= 0.0005 (mho/cm2)
	
} 

STATE { 
	s 
	f
} 

ASSIGNED { 
	ina (mA/cm2) 
	g (mho/cm2) 
      alpha_s (/ms)
	beta_s (/ms)
	s_inf
	tau_s (ms)
	alpha_f (/ms)
	beta_f (/ms)
	f_inf
	tau_f (ms) 
      ena(mV)
      celsius (degC) 
      v (mV) 
} 
 
INITIAL { 
	rate(v) 
      s = s_inf
	f = f_inf
} 
 
BREAKPOINT { 
	SOLVE states METHOD derivimplicit 
	g = gnabar*s*f
	ina = g*(v - ena)

	alpha_s = alp_s(v)
	beta_s = bet_s(v) 

	alpha_f = alp_f(v)
	beta_f = bet_f(v) 
} 
 
DERIVATIVE states { 
	rate(v) 
	s' = ( s_inf - s ) / tau_s 
	f' = ( f_inf - f ) / tau_f 
} 
 
PROCEDURE rate(v (mV)) { LOCAL a_s,b_s,a_f,b_f

	a_s = alp_s(v)  
	b_s = bet_s(v) 
	s_inf = a_s / ( a_s + b_s ) 
	tau_s = 1 / ( a_s + b_s ) 

	a_f = alp_f(v)  
	b_f = bet_f(v) 
	f_inf = a_f / ( a_f + b_f ) 
	tau_f = 1 / ( a_f + b_f ) 
} 



FUNCTION alp_s(v (mV)) (/ms){ LOCAL Q10
	Q10 = 3^( ( celsius - 20 (degC) ) / 10 (degC) )
if((v+V0alpha_s)/Kalpha_s >200){
alp_s = Q10*(Shiftalpha_s+Aalpha_s*((v+V0alpha_s)/ 1 (mV) )/
(exp(200)-1))
}else{
	alp_s = Q10*(Shiftalpha_s+Aalpha_s*((v+V0alpha_s)/ 1 (mV) )/(exp((v+V0alpha_s)/Kalpha_s)-1))
}
}
FUNCTION bet_s(v (mV)) (/ms){ LOCAL Q10
	Q10 = 3^((celsius-20(degC))/10(degC))
if(((v+V0beta_s)/Kbeta_s)>200){
bet_s =	Q10*(Shiftbeta_s+Abeta_s*((v+V0beta_s)/1 (mV) )/
(exp(200)-1))
}else{	
	bet_s =	Q10*(Shiftbeta_s+Abeta_s*((v+V0beta_s)/1 (mV) )/(exp((v+V0beta_s)/Kbeta_s)-1))
}
}

FUNCTION alp_f(v (mV)) (/ms){ LOCAL Q10
	Q10 = 3^( ( celsius - 20 (degC) ) / 10 (degC) )
if(( v - V0alpha_f )/Kalpha_f >200){
alp_f =	Q10 * Aalpha_f * exp(200)
}else{
	alp_f =	Q10 * Aalpha_f * exp(( v - V0alpha_f )/Kalpha_f)
}
}
FUNCTION bet_f(v (mV)) (/ms){ LOCAL Q10
	Q10 = 3^( ( celsius - 20 (degC) ) / 10 (degC) )
if(( v - V0beta_f )/Kbeta_f >200){
bet_f =	Q10 * Abeta_f * exp(200)	
}else{
	bet_f =	Q10 * Abeta_f * exp(( v - V0beta_f )/Kbeta_f )	
}
}


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