Controlling Pyramidal Cell Activity by Bistable Gamma-Frequency Oscillations in a Network of Hippo Campal Interneurons

Inhibitory networks play a crucial role in regulating the activity of target neurons: distinct patterns of interneuronal activity and transitions between them influence the excitability of pyramidal cells. Multiple neurons of a recurrently connected interneuron network converging on the perisomatic region of a single pyramidal cell is presented. Interneurons display two distinct modes of activity: in-phase or anti-phase locked oscillation in the gamma-band. The periodic inhibition either gates the firing of the pyramidal cell periodically or expresses time-dispersed inhibition depending on the two states of the network. Conditions necessary for completely suppressing action-potential generation or blocking back-propagation is explored. The functional role of the mechanism (e.g. in plasticity) is discussed