Fig. 25

A Schematics representing the neuronal network. A group of 2000 excitatory neurons and 500 inhibitory neurons are recurrently connected with sparse connectivity and the excitatory neurons receive random input from an external pool of neurons. B Excitatory neurons’ mean firing-rate (top), mean excitatory weight onto excitatory neurons (middle) and mean inhibitory weight onto excitatory neurons (connections marked as plastic in A). Simulation of the neuronal network with a spike-based inhibitory learning rule is represented by green lines (STDP) while simulation with our novel spike-timing- and current-dependent learning rule is shown in yellow (STCDP). The dashed lines represent the fixed points imposed by the excitatory (high) and inhibitory (low) learning rules. The low fixed point only exists for the inhibitory STDP model (simulation represented by the green lines)