Neocortical rhythm entrainment by parvalbumin-positive interneurons across cortical layers

Neocortical interneurons provide local inhibition responsible for organizing neuronal activity into brain oscillations that subserve several functions such as memory, attention and neuronal communication. However, little is known about the contribution of interneurons to the entrainment of neocortical oscillations across cortical layers. Here, using layer-specific optogenetic stimulations with micro-Light-Emitting-Diode (μLED) arrays, directed toward parvalbumin-expressing (PV) interneurons in non-anesthetized awake mice, we find that supragranular layer stimulations of PV neurons were most efficient at entraining supragranular layer neurons and local field potential (LFP) oscillations at gamma frequencies (γ: 25 - 80 Hz), whereas infragranular layer stimulation of PV neurons better entrained delta (δ: 2 - 5 Hz) and theta (θ: 6 - 10 Hz) frequency LFP oscillations. We found that PV neurons tightly control the transmission of multiple rhythms to the network across cortical layers in an orientation-selective manner. Intrinsic resonant properties of neurons could underlie such layer-specific properties of rhythm entrainment. ### Competing Interest Statement The authors have declared no competing interest.