Synaptic variance and action potential firing of cerebellar output neurons during motor learning in larval zebrafish

Marion Najac, David McLean, Indira M. Raman*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)3299-3311.e3
JournalCurrent Biology
Issue number16
StatePublished - Aug 21 2023


  • cerebellum
  • conditioning
  • EPSC
  • eurydendroid
  • fictive swimming
  • IPSC
  • spike timing

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)


Dive into the research topics of 'Synaptic variance and action potential firing of cerebellar output neurons during motor learning in larval zebrafish'. Together they form a unique fingerprint.

Cite this