Inferior Olive, subthreshold oscillations (Torben-Nielsen, Segev, Yarom 2012)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:144502
The Inferior Olive is a brain structure in which neurons are solely connected to each other through gap-junctions. Its behavior is characterized by spontaneous subthreshold oscillation, frequency changes in the subthreshold oscillation, stable phase differences between neurons, and propagating waves of activity. Our model based on actual IO topology can reproduce these behaviors and provides a mechanistic explanation thereof.
Reference:
1 . Torben-Nielsen B, Segev I, Yarom Y (2012) The generation of phase differences and frequency changes in a network model of inferior olive subthreshold oscillations. PLoS Comput Biol 8:e1002580 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Realistic Network;
Brain Region(s)/Organism:
Cell Type(s): Inferior olive neuron;
Channel(s): I T low threshold;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s): Gaba;
Simulation Environment: NEURON;
Model Concept(s): Oscillations;
Implementer(s): Torben-Nielsen, Ben [btorbennielsen at gmail.com];
Search NeuronDB for information about:  I T low threshold; Gaba;
COMMENT
Ca channel from Manor (Rinzel, Segev, Yarom) 1997
Channel can cause sub-threshold oscillations in interplay with the leak

B. Torben-Nielsen @ HUJI, 7-10-2010
ENDCOMMENT

NEURON {
       SUFFIX stoca
       :USEION ca WRITE ica
       NONSPECIFIC_CURRENT i
       RANGE mMidV,gbar,g,i,minf,hinf,tauh,m,h,ecas : now i can access these variables
}

UNITS {
      (S) = (siemens)
      (mS) = (millisiemens)
      (mV) = (millivolt)
      (mA) = (milliamp)
}

PARAMETER {
	  ecas = 120 (mV)
	  gbar = 0.4 (mS/cm2)
      mMidV=-61 (mV) : -61 default from mnaor. can be set to other values, e.g., to test 'windowness' of the current
}

ASSIGNED {
	 v (mV)
	 i (mA/cm2)
	 g (mS/cm2)
	 minf 
	 hinf 
	 tauh (ms)
}

STATE {
      m 
      h
}

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

BREAKPOINT {
	   rates(v)
	   SOLVE states METHOD cnexp
	   g = gbar *minf*h
	   i = g * (v - ecas)*(0.001)
	   :ica = i
}

DERIVATIVE states {
	   h' = (hinf -h)/tauh
}

PROCEDURE rates(v (mV)) {
	  : updates formulas with earlier activation, e_r=-70, e_l=-78 (i.e., at lower amplitudes)
	  :hinf =1/( 1+exp( (v+100.5)/8.6 ) )
	  :minf = 1/(  (1+exp((-75.5-v)/4.2)) *(1+exp((-75.5-v)/4.2))* (1+exp((-75.5-v)/4.2)) )
	  :tauh=55+30*(1/( 1+exp((v+99.0)/7.3) ))*exp((v+175.0)/30.0)

	  : below the original ones
	  UNITSOFF
	  hinf =1/( 1+exp( (v+85.5)/8.6 ) ) :85.5
	  tauh=40+30*(1/( 1+exp((v+84.0)/7.3) ))*exp((v+160.0)/30.0)
 	  minf = 1/(  (1+exp((mMidV-v)/4.2)) *(1+exp((mMidV-v)/4.2))* (1+exp((mMidV-v)/4.2)) )
	  m = minf
	  UNITSON
}

Loading data, please wait...