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IfbNeuron
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Subsections

IfbNeuron

see Izhikevich E. "Which modell to use for cortical spiking neurons?"

Model

A leaky-integrate-and-fire-or burst neuron model is implemented where the membrane potential Vm of a neuron is given by

\begin{displaymath}\tau_m \frac{d V_m}{dt} = -(V_m-V_{resting}) + R_m \cdot (I_{syn}(t)+I_{inject}+I_{noise}) \end{displaymath}

where $\tau_m=C_m\cdot R_m$ is the membrane time constant, Rm is the membrane resistance, Isyn(t) is the current supplied by the synapses, Iinject is a non-specific background current and Inoise is a Gaussion random variable with zero mean and a given variance noise.

At time t=0 Vm ist set to Vinit . If Vm exceeds the threshold voltage Vthresh it is reset to Vreset and hold there for the length Trefract of the absolute refractory period.

Implementation

The exponential Euler method is used for numerical integration.

Read/writable Fields

Cm (F) :
The membrane capacity Cm
Rm (Ohm) :
The membrane resistance Rm
Vthresh (V) :
If Vm exceeds Vthresh a spike is emmited.
Vresting (V) :
The resting membrane voltage.
Vreset (V) :
The voltage to reset Vm to after a spike.
Vinit (V) :
The initial condition for Vm at time t=0.
Trefract (sec) :
The length of the absolute refractory period.
Inoise (A) :
The standard deviation of the noise to be added each integration time constant.
Iinject (A) :
A constant current to be injected into the LIF neuron.
h :
internal parameter h - deinactivation of Ca-channels
tau_p :
tau_p time constant for recovery from inactivation
tau_m :
tau_m time constant for inactivation
Vh :
Vh constant for onset of Ca-channel activation.
gh :
gh constant for relative impact of Ca-current to leak current (0.5-2)
type :
Type (e.g. inhibitory or excitatory) of the neuron

Readonly Fields

Vm (V) :
The membrane voltage Vm
Isyn :
synaptic input current
nIncoming :
Number of incoming synapses
nOutgoing :
Number of outgoing synapses

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