Functional fission of parvalbumin interneuron classes during fast network events
Abstract
Fast spiking, parvalbumin (PV) expressing hippocampal interneurons are classified into basket, axo-axonic (chandelier) and bistratified cells. These cell classes play key roles in regulating local circuit operations and rhythmogenesis by releasing GABA in precise temporal patterns onto distinct domains of principal cells. Here we show that each of the three major PV cell classes further splits into functionally distinct subclasses during fast network events in vivo. During the slower (<10Hz) theta oscillations, each cell class exhibited its own characteristic, relatively uniform firing behavior. However, during faster (>90Hz) oscillations, within-class differences in PV interneuron discharges emerged that segregated along specific features of dendritic structure or somatic location. Functional divergence of PV subclasses during fast but not slow network oscillations effectively doubles the repertoire of spatio-temporal patterns of GABA release available for rapid circuit operations.
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Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All procedures were approved by the University of California Irvine Animal Care and Use Committee (protocol #1999-1719) and the University of Pecs, Hungary . All surgery was performed under deep isoflurane anesthesia, and every effort was made to minimize suffering.
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© 2014, Varga et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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