A neurosynaptic model of state-dependent EEG wave generation in the subcortico-cortical system

A neurosynaptic model of the subcortico-cortical system is presented in order to analyze the mechanism for the generation of EEG rhythms with specific state-dependent spectral patterns. The model is based on the interaction among the infraslow, as well as basic, rhythms of the PSP's (postsynaptic potentials) trains from which CSD's (current source densities) or cortical surface potentials emerge. The model system was simulated by two trains of positive and negative cortical surface potentials within the same period, according to the thalamic clock as modulated by the infraslow rhythms of the midbrain reticular system. The simulated EEG's showed rhythmic waxing and waning sawtooth-like waves with no frequency fluctuation, but with some spectral broadband peaks at the basic repetitive frequency, as well as its harmonics.