Somatic and dendritic small-conductance calcium-activated potassium channels regulate the output of cerebellar Purkinje neurons

Mary D. Womack, Kamran Khodakhah

Research output: Contribution to journalArticle

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Abstract

Cerebellar Purkinje neurons provide the sole output of the cerebellar cortex and play a crucial role in motor coordination and maintenance of balance. They are spontaneously active, and it is thought that they encode timing signals in the rate and pattern of their activity. An understanding of factors that control their excitability is important for delineating their computational role in the cerebellum. We evaluated the role of small-conductance calcium-activated potassium (SK) channels in the regulation of activity of mouse and rat Purkinje neurons. We find that somatic SK channels effectively limit the maximum firing rate of Purkinje neurons; when SK channels are blocked by the specific antagonists apamin or scyllatoxin, cells fire spontaneously at rates as high as 500 spikes per second. Dendritic SK channels, however, control primarily the extent to which dendrites contribute to the firing rate of Purkinje cells. Given their presence in the dendrites, it is likely that SK channels in the proximal dendrites govern the efficacy of dendrosomatic electrical coupling. When studied under physiological conditions, it is found that SK channels play the same role in controlling the excitability of adult Purkinje neurons as they do in young cells.

Original languageEnglish (US)
Pages (from-to)2600-2607
Number of pages8
JournalJournal of Neuroscience
Volume23
Issue number7
Publication statusPublished - Apr 1 2003

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Keywords

  • Apamin
  • Calcium-activated potassium channels
  • Cerebellum
  • Motor coordination
  • Purkinje cells
  • Trimodal pattern of activity

ASJC Scopus subject areas

  • Neuroscience(all)

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