Julia Veit: Cortical Gamma-band Synchronisation through Somatostatin Interneurons

Abstract

Oscillations in the gamma band are thought to synchronize distributed cell ensembles to facilitate information transfer within and across brain areas. The mechanism generating these rhythms, however, remains hotly debated. Most circuit models have focused on soma-targeting, parvalbumin-positive GABAergic neurons as the essential source of inhibition necessary for gamma rhythms. Using cell-type-specific optogenetic manipulations in awake, behaving mice, we show that the activity of dendrite-targeting somatostatin neurons are critical for a contextual, visually-induced gamma oscillation in the primary visual cortex of mice. Furthermore, somatostatin neurons are required for long-distance coherence across the visual cortex. Preliminary data shows the potential involvement of a third interneuron-type, VIP neurons, in tuning this gamma oscillation. These data establish an alternative mechanism for cortical synchronization of distributed networks.