Home CSIM Circuits Learning Download Research Benchmark Tests References People Links
 
CSIM: CbStOuNeuron Class Reference
Main Page | Class Hierarchy | Alphabetical List | Class List | File List | Class Members | File Members | Related Pages

CbStOuNeuron Class Reference

#include <cbstouneuron.h>

Inheritance diagram for CbStOuNeuron:

CbNeuronSt CbNeuron SpikingNeuron MembranePatch Neuron MembranePatchSimple Forceable SynapseTarget Advancable csimClass 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, a spike template and Ornstein Uhlenbeck process noise.

Model

The membrane voltage $V_m$ is governed by

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

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)
  • $g_{noise}^{exz}(t)$ excitatory coductance given Ornstein Uhlenbeck process noise
  • $E_{noise}^{exc}$ reversal potential for excitatory Ornstein Uhlenbeck process noise
  • $g_{noise}^{inh}(t)$ inhibitory coductance given Ornstein Uhlenbeck process noise
  • $E_{noise}^{inh}$ reversal potential for inhibitory Ornstein Uhlenbeck process noise
  • $I_{inject}$ 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 ge
    exc and inh conductances (noise) [readwrite; units=S;]
  • double ge0
    exc and inh mean conductances (noise) [readwrite; units=S;]
  • double tau_e
    time constants and std for exc and inh conductances (noise) [readwrite; units=S;]
  • double Ee
    Reversal potential for exc and inh currents (noise) [readwrite; units=V;].

Protected Attributes

Private Attributes

  • double Ae
    constant for Ornstein Uhlenbeck process [hidden;]

Friends

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