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 }