Nakajima, Ryuichi Laskaris, Nikolaos Rhee, Jun Kyu Baker, Bradley J. Kosmidis, Efstratios K. 2024-01-19T14:34:29Z 2024-01-19T14:34:29Z 2021-10-21 2021-05 0953-816X https://pubs.kist.re.kr/handle/201004/117040 The CA1 area in the mammalian hippocampus is essential for spatial learning. Pyramidal cells are the hippocampus output neurons and their activities are regulated by inhibition exerted by a diversified population of interneurons. Lateral inhibition has been suggested as the mechanism enabling the reconfiguration of pyramidal cell assembly activity observed during spatial learning tasks in rodents. However, lateral inhibition in the CA1 lacks the overwhelming evidence reported in other hippocampal areas such as the CA3 and the dentate gyrus. The use of genetically encoded voltage indicators and fast optical recordings permits the construction of cell-type specific response maps of neuronal activity. Here, we labelled mouse CA1 pyramidal neurons with the genetically encoded voltage indicator ArcLight and optically recorded their response to Schaffer Collaterals stimulation in vitro. By undertaking a manifold learning approach, we report a hyperpolarization-dominated area focused in the perisomatic region of pyramidal cells receiving late excitatory synaptic input. Functional network organization metrics revealed that information transfer was higher in this area. The localized hyperpolarization disappeared when GABA(A) receptors were pharmacologically blocked. This is the first report where the spatiotemporal pattern of lateral inhibition is visualized in the CA1 by expressing a genetically encoded voltage indicator selectively in principal neurons. Our analysis suggests a fundamental role of lateral inhibition in CA1 information processing. English WILEY GEVI cell-type specific labelling and a manifold learning approach provide evidence for lateral inhibition at the population level in the mouse hippocampal CA1 area Article 10.1111/ejn.15177 1 EUROPEAN JOURNAL OF NEUROSCIENCE, v.53, no.9, pp.3019 - 3038 EUROPEAN JOURNAL OF NEUROSCIENCE 53 9 3019 3038 scie scopus 000631510800001 2-s2.0-85102867701 Neurosciences Neurosciences & Neurology Article FEEDFORWARD INHIBITION GABAERGIC INHIBITION AXONAL PROJECTIONS PYRAMIDAL CELLS INTERNEURONS ORGANIZATION DYSFUNCTION CIRCUITS DYNAMICS POTENTIATION ArcLight CA1 functional network organization genetically encoded voltage indicators lateral inhibition manifold learning optical recordings