How does inhibition set the pace of fast brain rhythms? · Grey Matter

When a group of fast-spiking interneurons fires, the GABA-A inhibition it delivers silences the pyramidal cells around it for a few milliseconds.

How does inhibition set the pace of fast brain rhythms?

When a group of fast-spiking interneurons fires, the GABA-A inhibition it delivers silences the pyramidal cells around it for a few milliseconds. As that inhibition wears off, the pyramidal cells that are being driven fire together in the short window that opens, excite the interneurons again, and the cycle repeats. The decay time of GABA-A inhibition sets the period, which is why such loops oscillate in the gamma range, roughly 30 to 90 Hz. Because these rhythms come from the inhibitory side of the circuit, gamma is often read as a sign of how well inhibition is working.