Synaptic variance and action potential firing of cerebellar output neurons during motor learning in larval zebrafish
The cerebellum regulates both reflexive and acquired movements. Here, by recording voltage-clamped synaptic currents and spiking in cerebellar output (eurydendroid) neurons in immobilized larval zebrafish, we investigated synaptic integration during reflexive movements and throughout associative mot...
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Published in | Current biology Vol. 33; no. 16; pp. 3299 - 3311.e3 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
England
21.08.2023
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Subjects | |
Online Access | Get full text |
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Summary: | The cerebellum regulates both reflexive and acquired movements. Here, by recording voltage-clamped synaptic currents and spiking in cerebellar output (eurydendroid) neurons in immobilized larval zebrafish, we investigated synaptic integration during reflexive movements and throughout associative motor learning. Spiking coincides with the onset of reflexive fictive swimming but precedes learned swimming, suggesting that eurydendroid signals may facilitate the initiation of acquired movements. Although firing rates increase during swimming, mean synaptic inhibition greatly exceeds mean excitation, indicating that learned responses cannot result solely from changes in synaptic weight or upstream excitability that favor excitation. Estimates of spike threshold crossings based on measurements of intrinsic properties and the time course of synaptic currents demonstrate that noisy excitation can transiently outweigh noisy inhibition enough to increase firing rates at swimming onset. Thus, the millisecond-scale variance of synaptic currents can regulate cerebellar output, and the emergence of learned cerebellar behaviors may involve a time-based code. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Author Affiliation Addresses (for all authors): Department of Neurobiology, 2205 Tech Drive, Northwestern University, Evanston, IL 60208 Author contributions: M.N conducted experiments and analyzed data. M.N., D.L.M., and I.M.R. designed experiments. M.N. and I.M.R. wrote the manuscript. M.N, D.L.M., and I.M.R. edited the manuscript. |
ISSN: | 0960-9822 1879-0445 1879-0445 |
DOI: | 10.1016/j.cub.2023.06.045 |