The interlaminar and horizontal connectivity of the neocortex segregates its neuronal elements into localnetworks. The cellular mechanisms underlying cortical network activity, and the impact of local corticalnetwork activity during sensory processing remain largely unknown. In vivo, neurons of the neocortex exhibitrhythmic, spontaneous cycles of synaptically mediated depolarization, termed UP states, followed bycessation of synaptic activity, termed DOWN states. This proposal will specifically examine the cellular basisand functional consequences of spontaneous, persistent activity during UP states in the mammalianneocortex in vivo.
The first aim of this proposal will characterize the contributions of excitation and inhibitionduring the spontaneous network activity of the UP state. This will be accomplished via single and pairedintracellular recording, simultaneous with extracellular unit and local field potential recordings in anesthetizedferret prefrontal cortex.
The second aim of this proposal will assess the effect of this ongoing networkactivity upon visual responsiveness of neurons in cat visual cortex, using methods described above. Theproposed plan will provide insights into the dynamic operation of intact neocortical circuits.
