Novel Granule cell-Golgi cell excitatory inputs in the cerebellar granular layer

Abstract

Event Abstract Back to Event Novel Granule cell-Golgi cell excitatory inputs in the cerebellar granular layer Elisabetta Cesana1, 2*, Stéphane Dieudonné3, Philippe Isope4, Céline Bidoret3, Egidio D‘Angelo1, 2 and Lia Forti5 1 University of Pavia and CNISM, Department of Physiology, Italy 2 IRCCS C. Mondino, Brain Connectivity Center, Italy 3 Ecole Normale Supérieure, Neurobiology Laboratory, CNRS UMR 8544, France 4 Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, France 5 University of Insubria, Department of Structural and Functional Biology, Italy Golgi cells (GoCs), the main inhibitory interneurons in the cerebellar granular layer, receive excitation from mossy fibres (Mf) and granule cells (GrC). To explore functional properties of these inputs, we recorded excitatory synaptic currents (EPSCs) evoked by extracellular white matter (WM) stimulation in whole-cell clamped GoCs in parasagittal cerebellar slices (rat, P17-23; 32°C). WM stimuli elicited short-latency monosynaptic (SL-EPSC) and long-latency disynaptic (LL-EPSCs) responses. SL-EPSCs were identified as arising at Mf-GoC contacts; they had fast kinetics (t20-80% rise: 80-160 us; fast decay tau: 0.27 to 0.67ms) and an NMDA receptor-mediated component subject to strong Mg2+ block. Pharmacological manipulation showed that LL-EPSCs depended on GrC excitation; their kinetics varied across cells, from very fast, similar to Mf-GoC EPSCs, up to 10-fold slower, similar to parallel fibre (pf)-evoked EPSCs. This suggested that some LL-EPSCs might arise at short electrotonic distance from the soma, in GoC basolateral (bl) dendrites. To locate the site of origin of SL- and LL-EPSCs, we imaged the NMDAR-mediated postsynaptic Ca2+ influx, using a random-access, ultra-fast 2-photon microscope (Otsu et al. 2008) in Fluo-4-filled GoCs bathed in Mg2+-free saline. In bl dendrites, we detected Ca2+ transients (CaTs) with latency and failures corresponding to SL-EPSCs, as well as CaTs corresponding to disynaptic events, suggesting functional contacts from GrC ascending axons (aA). Existence of these contacts was confirmed by analysis of i) EM images in GlyT2-GFP labelled mice and of ii) kinetic properties of unitary EPSCs in GrC-GoC paired recordings, where fast EPSCs were seen in about half of the connected pairs. These data show that GrC make functional synaptic contacts with GoC bl dendrites via their aA; thus local feed-back and feed-forward inhibitory circuits share similar inputs on proximal GoC dendrites, which differ from associative pf inputs on distal apical dendrites. Acknowledgements Supported by EU grants SENSOPAC, CYBERRAT and NEUROIMAGE to E.D., CNRS, INSERM and ANR Neuro-OAC to S.D. Keywords: Cerebellum Conference: The Cerebellum: from neurons to higher control and cognition, Pavia, Italy, 8 Jul - 9 Jul, 2010. Presentation Type: Short Communication Topic: The Cerebellum: from neurons to higher control and cognition Citation: Cesana E, Dieudonné S, Isope P, Bidoret C, D‘Angelo E and Forti L (2010). Novel Granule cell-Golgi cell excitatory inputs in the cerebellar granular layer. Front. Neurosci. Conference Abstract: The Cerebellum: from neurons to higher control and cognition. doi: 10.3389/conf.fnins.2010.83.00016 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Sep 2010; Published Online: 15 Oct 2010. * Correspondence: Dr. Elisabetta Cesana, University of Pavia and CNISM, Department of Physiology, Pavia, Italy, elisabetta.cesana@unipv.it Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Elisabetta Cesana Stéphane Dieudonné Philippe Isope Céline Bidoret Egidio D‘Angelo Lia Forti Google Elisabetta Cesana Stéphane Dieudonné Philippe Isope Céline Bidoret Egidio D‘Angelo Lia Forti Google Scholar Elisabetta Cesana Stéphane Dieudonné Philippe Isope Céline Bidoret Egidio D‘Angelo Lia Forti PubMed Elisabetta Cesana Stéphane Dieudonné Philippe Isope Céline Bidoret Egidio D‘Angelo Lia Forti Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.