A standard leaky-integrate-and-fire 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.


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.
type :
Type (e.g. inhibitory or excitatory) of the neuron

Readonly Fields

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

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