Figure 2.
I-I and E-I models of gamma oscillations. (a) Clock-like rhythm of coupled oscillators in an interneuronal (I-I) population. (Upper panel) Single interneurons fire spikes periodically at ~40 Hz. Mutual inhibition via GABAA receptors quickly brings them to zero-phase synchrony; (lower panel) two example neurons. Adapted from Wang & Buzsáki (1996). (b,c) Sparsely synchronous oscillations in a neural circuit where single neuronal spiking is stochastic. Adapted from Geisler et al. (2005). (b) Interneuronal population in noise-dominated regime typically exhibits gamma power in the higher frequency range, in contrast to (a) the clock-like rhythmic case. (c) Reciprocally connected E-I network where pyramidal cells send fast excitation via AMPA receptors to interneurons, which in turn provide inhibition via GABAA receptors, leading to coherent oscillations in the gamma-frequency range.
