Command: izhikevich

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Name:
 izhikevich - Izhikevich neuron model

Description:
     Implementation of the simple spiking neuron model introduced by Izhikevich [1].
     The dynamics are given by:
         dv/dt = 0.04*v^2 + 5*v + 140 - u + I
	    du/dt = a*(b*v - u)

	 if v >= V_th:
 	   v is set to c
	   u is incremented by d

	 v jumps on each spike arrival by the weight of the spike. 
   
     As published in [1], the numerics differs from the standard forward Euler technique 
     in two ways: 
     1) the new value of u is calulated based on the new value of v, rather than the 
        previous value
     2) the variable v is updated using a time step half the size of that used to update 
        variable u. 
   
     This model offers both forms of integration, they can be selected using the
     boolean parameter consistent_integration. To reproduce some results published on 
	 the basis of this model, it is necessary to use the published form of the dynamics.
     In this case, consistent_integration must be set to false. For all other purposes,
     it is recommended to use the standard technique for forward Euler integration. In 
     this case, consistent_integration must be set to true (default).


Parameters:
     The following parameters can be set in the status dictionary.

     V_m        double - Membrane potential in mV
     U_m		double - Membrane potential recovery variable
     V_th       double - Spike threshold in mV.
     I_e        double - Constant input current in pA. (R=1)
     V_min      double - Absolute lower value for the membrane potential.
     a			double - describes time scale of recovery variable
     b			double - sensitivity of recovery variable
     c			double - after-spike reset value of V_m
     d			double - after-spike reset value of U_m
	 consistent_integration		bool - use standard integration technique


References:
     [1] Izhikevich, Simple Model of Spiking Neurons,
     IEEE Transactions on Neural Networks (2003) 14:1569-1572

Sends:
 SpikeEvent

Receives:
 SpikeEvent, CurrentEvent, DataLoggingRequest
FirstVersion:
 2009
Author:
 Hanuschkin, Morrison, Kunkel
SeeAlso:iaf_psc_delta mat2_psc_exp
Source:
 /home/abuild/rpmbuild/BUILD/nest-2.4.1/models/izhikevich.h

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