101214 Bartos

The Bernstein Center Freiburg

Bernstein Seminar

Marlene Bartos

Cellular and Systemic Neurophysiology
Institute for Physiology I
University of Freiburg, Germany

Distance-dependent perisomatic inhibition: a new mechanism underlying network synchronization

Abstract:
GABAergic perisomatic-targeting inhibitory interneurons (PIIs) are thought to effectively control the activity of large neuronal cell populations by their wide axonal arborisation. The spatiotemporal output pattern of one PII onto all its target cells was assumed to be homogeneously rapid and strong. It was further shown that these synaptic properties are optimized to support network synchronization at gamma (30-90 Hz) frequencies. Here, we present first evidence that strength and time course of inhibitory signals is changing with distance between synaptically interacting partners in the hippocampus resulting in strong and fast inhibition among close neighbours and weak and slow inhibition among distant neighbours. We further show that this “distance-dependence” of inhibitory signalling critically supports the emergence of synchronous gamma-oscillations in large-scale cortical network models.

Host: Ad Aertsen