Expression of Kv3.1 and Kv4.2 genes in developing cerebellar granule cells

Riichi Shibata, Yoshihiko Wakazono, Kensuke Nakahira, James Trimmer, Kazuhiro Ikenaka

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

The expression of voltage-gated potassium channels plays an important role in the acquisition of membrane excitability in neurons. We examined the expression pattern of genes in developing cerebellar granule neurons in vivo and in vitro. In situ hybridization of Kv3.1 mRNA demonstrated that the gene was expressed at high levels in the external granule layer (EGL) as well as in the internal granule layer (IGL) at all postnatal stages (P) examined (from P3 to P10). In contrast, Kv4.2 mRNA was detected in the premigratory zone (PMZ) of the EGL, but not in the proliferative zone (PLZ), in addition to the IGL. This indicates that Kv4.2 gene expression initiates in the postmitotic migrating neurons. We also examined the expression of the channel genes in microexplant culture systems. Kv3.1 polypeptide was detected in parallel fibers of granule cells at 2 days in vitro, and the expression continued in later stages. The signal of Kv4.2 protein was very low at 2 days in vitro; however, the number of positive cells and the intensity of the signals were increased at 6 days in vitro. These in vitro observations matched those in vivo and our previous electrophysiological studies in which we demonstrated that delayed-rectifier-type current was predominant in the immature granule cells followed by the later appearance of A-type current. The patterns of K+ channel expression suggest that sequential expression of these channel genes primarily determines the membrane excitability.

Original languageEnglish (US)
Pages (from-to)87-93
Number of pages7
JournalDevelopmental Neuroscience
Volume21
Issue number2
DOIs
StatePublished - Jul 1999
Externally publishedYes

Keywords

  • Cerebellar granule cell
  • Development
  • Immunohistochemistry
  • In situ hybridization
  • Kv3.1
  • Kv4.2
  • Microexplant culture
  • Voltage-gated K channel

ASJC Scopus subject areas

  • Neuroscience(all)

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