The membrane voltage
is governed by V m
with the following meanings of symbols
membrane capacity (Farad)
reversal potential of the leak current (Volts)
membrane resistance (Ohm)
total number of channels (active + synaptic)
current conductance of channel g ( c t) (Siemens)
reversal potential of channel E rev c (Volts)
total number of current supplying synapses
current supplied by synapse I ( s t) (Ampere)
total number of coductance based synapses
coductance supplied by synapse g ( s t) (Siemens)
reversal potential of synapse E rev ( s) (Volts)
injected current (Ampere)
t=0 ist set to V m .
The value of
is calculated to compensate for ionic currents such that E m actually has a resting value of
V m .
If the membrane voltage
exceeds the threshold V m the CbNeuronSt sends a spike to all its outgoing synapses and the V tresh membrane voltage follows a predefined spike templage during the absolute refractory period of length T refract if doReset = 1.
If the flag
doReset=0 the spike template is not applied and the above equation is also applied during the absolute refractory period but the event of threshold crossing is transmitted as a spike to outgoing synapses. This is usfull if one includes channels which produce a real action potential (see HH_K_Channel and HH_Na_Channel) but one still just wants to communicate the spikes as events in time.
The exponential Euler method is used for numerical integration.
STempHeight ( ) : Volt
Vthresh ( ) : V
exceeds V m a spike is emmited. V thresh
Vreset ( ) : V
The voltage to reset
to after a spike. V m
doReset ( ) : flag
Flag which determines wheter
should be reseted after a spike V m
Trefract ( ) : sec
Length of the absolute refractory period.
nummethod ( ) : flag
Numerical method for the solution of the differential equation: Exp. Euler = 0, Crank-Nicolson = 1
Type (e.g. inhibitory or excitatory) of the neuron
Cm ( ) : F
The membrane capacity
Rm ( ) : Ohm
The membrane resistance
Vresting ( ) : V
The resting membrane voltage.
Vinit ( ) : V
Initial condition for
at time V m . t=0
VmScale ( ) : V
Defines the difference between Vresting and the Vthresh for the calculation of the iongate tables and the ionbuffer Erev.
Inoise ( ) : W 2
Variance of the noise to be added each integration time constant.
Iinject ( ) : A
Constant current to be injected into the CB neuron.
Em ( ) : V
The reversal potential of the leakage channel
Vm ( ) : V
The membrane voltage
synaptic input current
synaptic input conductance
Number of incoming synapses
Number of outgoing synapses
Number of ion buffers
Number of channels