A stable proportion of Purkinje cell inputs from parallel fibers are silent during cerebellar maturation.

Autor:	Ho S; Aix-Marseille Université, INSERM, INMED, Marseille 13009, France., Lajaunie R; Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom., Lerat M; Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris F-75012, France., Le M; Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris F-75012, France., Crépel V; Aix-Marseille Université, INSERM, INMED, Marseille 13009, France., Loulier K; Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris F-75012, France., Livet J; Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris F-75012, France., Kessler JP; Aix-Marseille Université, CNRS, Institut de Biologie du Développement de Marseille, UMR 7288, Marseille 13288, France., Marcaggi P; Aix-Marseille Université, INSERM, INMED, Marseille 13009, France; paikan.marcaggi@univ-amu.fr.; Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom.; Unité de Neurobiologie des Canaux Ioniques et de la Synapse, UMR 1072, INSERM, Aix-Marseille Université, Marseille 13015, France.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Nov 09; Vol. 118 (45).
DOI:	10.1073/pnas.2024890118
Abstrakt:	Cerebellar Purkinje neurons integrate information transmitted at excitatory synapses formed by granule cells. Although these synapses are considered essential sites for learning, most of them appear not to transmit any detectable electrical information and have been defined as silent. It has been proposed that silent synapses are required to maximize information storage capacity and ensure its reliability, and hence to optimize cerebellar operation. Such optimization is expected to occur once the cerebellar circuitry is in place, during its maturation and the natural and steady improvement of animal agility. We therefore investigated whether the proportion of silent synapses varies over this period, from the third to the sixth postnatal week in mice. Selective expression of a calcium indicator in granule cells enabled quantitative mapping of presynaptic activity, while postsynaptic responses were recorded by patch clamp in acute slices. Through this approach and the assessment of two anatomical features (the distance that separates adjacent planar Purkinje dendritic trees and the synapse density), we determined the average excitatory postsynaptic potential per synapse. Its value was four to eight times smaller than responses from paired recorded detectable connections, consistent with over 70% of synapses being silent. These figures remained remarkably stable across maturation stages. According to the proposed role for silent synapses, our results suggest that information storage capacity and reliability are optimized early during cerebellar maturation. Alternatively, silent synapses may have roles other than adjusting the information storage capacity and reliability. Competing Interests: The authors declare no competing interest.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu