Fig. 4. Behavior of the model at baseline. Spike raster plot of the neural network for 1 s, 5 h after initiation of the model. Each dot represents the firing of a neuron. The neurons are divided into two populations: excitatory neurons 0–6,143 and inhibitory neurons 6,144–7,680. Inhibitory neurons, with a much higher firing frequency, are seen as a darker band at the top of the plot (A) . Simulated electroencephalographic spectrogram demonstrating the development of theta and gamma rhythms under the influence of synaptic plasticity. Colors denote power of electroencephalogram at a particular frequency, red  indicating the highest power and violet  the lowest (B) .