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CSIM: CbNeuronSt Class Reference
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CbNeuronSt Class Reference

#include <cbneuronst.h>

Inheritance diagram for CbNeuronSt:

CbNeuron SpikingNeuron MembranePatch Neuron MembranePatchSimple Forceable SynapseTarget Advancable csimClass bNACNeuron cACNeuron CbStOuNeuron dNACNeuron bNACOUNeuron cACOUNeuron dNACOUNeuron List of all members.

Detailed Description

A single compartment neuron with an arbitrary number of channels, coductance based as well as current based synapses and a spike template.

Model

The membrane voltage $V_m$ is governed by

\[ C_m \frac{V_m}{dt} = -\frac{V_m-E_m}{R_m} - \sum_{c=1}^{N_c} g_c(t) ( V_m - E_{rev}^c ) + \sum_{s=1}^{N_s} I_s(t) + \sum_{s=1}^{G_s} g_s(t)(V_m-E_{rev}^{(s)}) + I_{inject} \]

with the following meanings of symbols

  • $C_m$ membrane capacity (Farad)
  • $E_m$ reversal potential of the leak current (Volts)
  • $R_m$ membrane resistance (Ohm)
  • $N_c$ total number of channels (active + synaptic)
  • $g_c(t)$ current conductance of channel $c$ (Siemens)
  • $E_{rev}^c$ reversal potential of channel $c$ (Volts)
  • $N_s$ total number of current supplying synapses
  • $I_s(t)$ current supplied by synapse $s$ (Ampere)
  • $G_s$ total number of coductance based synapses
  • $g_s(t)$ coductance supplied by synapse $s$ (Siemens)
  • $E_{rev}^{(s)}$ reversal potential of synapse $s$ (Volts)
  • $I_{inject}$ injected current (Ampere)

At time $t=0$ $V_m$ ist set to $V_{init}$ .

The value of $E_m$ is calculated to compensate for ionic currents such that $V_m$ actually has a resting value of $V_\mathit{resting}$ .

Spiking and reseting the membrane voltage

If the membrane voltage $V_m$ exceeds the threshold $V_{tresh}$ the CbNeuronSt sends a spike to all its outgoing synapses and the 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.

Implementation

The exponential Euler method is used for numerical integration.

Public Attributes

  • double STempHeight
    Height [readwrite; units=Volt; range=(0,1);].

Private Attributes

  • int STempIdxMax
    Internal constants for spike template calculations.

Static Private Attributes

  • static const double STEMP []
    Normalized spike template defining the membrane voltage $Vm$ during the refractory period.

Friends

 
(C) 2003, Thomas Natschläger last modified 07/10/2006