Simulation of antidromic stimulation was made by 1 nA, 0.1 ms long pulses injected in the Ranvier node (compartment named 'r3' in the neuron scripts) of each cell in the population. The orthodromic stimulation was made activating the AMPA-type channels.

 

We used a binomial distribution to set the activation time for each neuron in the assembly in order to simulate the temporal jitter.

 

Synaptic activation was simulated with alpha functions as follows: g_syn(t)=(t/tau_syn)(exp(1-t/tau_syn)). The synaptic currents are defined as I_syn= g_syn(t)(V_m-E_syn), with tau_syn of 2 and  7 ms and reversal potentials of 0 and -75 mV, for AMPA and  GABA_A mediated currents, respectively. GABA_A currents were distributed in the axon hillock, soma, basal stems and the proximal apical shaft, and turned on 1.5 ms after anti or orthodromic activation. See neuron scripts for the detailed description of the distribution of the synapses.

 

Compartmental transmembrane currents and potentials were calculated using the GENESIS simulator (Bower and Beeman, 1998). Calculations of field potentials and CSDs were programmed in dedicated C code.

 

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