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. 2018 Oct 18;14(10):e1006359. doi: 10.1371/journal.pcbi.1006359

Table 2. Model description after [49].

Model summary
Populations 254 populations: 32 areas (Table 1) with eight populations each (area TH: six)
Topology
Connectivity area- and population-specific but otherwise random
Neuron model leaky integrate-and-fire (LIF), fixed absolute refractory period (voltage clamp)
Synapse model exponential postsynaptic currents
Plasticity
Input independent homogeneous Poisson spike trains
Measurements spiking activity
Populations
Type Cortex
Elements LIF neurons
Number of populations 32 areas with eight populations each (area TH: six), two per layer
Population size N (area- and population-specific)
Connectivity
Type source and target neurons drawn randomly with replacement (allowing autapses and multapses) with area- and population-specific connection probabilities
Weights fixed, drawn from normal distribution with mean J such that postsynaptic potentials have a mean amplitude of 0.15 mV and standard deviation δJ = 0.1J; 4E to 2/3E increased by factor 2 [36]; weights of inhibitory connections increased by factor g; excitatory weights <0 and inhibitory weights >0 are redrawn; cortico-cortical weights onto excitatory and inhibitory populations increased by factor χ and χIχ, respectively
Delays fixed, drawn from Gaussian distribution with mean d and standard deviation δd = 0.5d; delays of inhibitory connections factor 2 smaller; delays rounded to the nearest multiple of the simulation step size h = 0.1 ms, inter-area delays drawn from a Gaussian distribution with mean d = s/vt, with distance s and transmission speed vt = 3.5 m/s [46]; and standard deviation δd = d/2, distances determined as the median of the distances between all vertex pairs of the two areas in their surface representation in F99 space, a standard macaque cortical surface included with Caret [47], where the vertex-to-vertex distance is the length of the shortest possible path without crossing the cortical surface [48] (see [35]), delays < 0.1 ms before rounding are redrawn
Neuron and synapse model
Name LIF neuron
Type leaky integrate-and-fire, exponential synaptic current inputs
Subthreshold dynamics dVdt=-V-ELτm+Is(t)Cm if (t > t* + τr)
V(t) = Vr else
Is(t)=i,kJke-(t-tik)/τsΘ(t-tik) k: neuron index, i: spike index
Spiking If V(t−) < θV(t+) ≥ θ
1. set t* = t, 2. emit spike with time stamp t*
Input
Type Background
Target LIF neurons
Description independent Poisson spikes (for each neuron, fixed rate νext = νbgkext with average external spike rate νbg = 10 spikes/s and number of external inputs per population kext, weight J)
Measurements
Spiking activity