Developmental profile of SK2 channel expression and function in CA1 neurons

Carmen Ballesteros-Merino, Mike Lin, Wendy W. Wu, Clotilde Ferrandiz-Huertas, María J. Cabañero, Masahiko Watanabe, Yugo Fukazawa, Ryuichi Shigemoto, James Maylie, John P. Adelman, Rafael Luján

Research output: Contribution to journalArticle

25 Scopus citations

Abstract

We investigated the temporal and spatial expression of SK2 in the developing mouse hippocampus using molecular and biochemical techniques, quantitative immunogold electron microscopy, and electrophysiology. The mRNA encoding SK2 was expressed in the developing and adult hippocampus. Western blotting and immunohistochemistry showed that SK2 protein increased with age. This was accompanied by a shift in subcellular localization. Early in development (P5), SK2 was predominantly localized to the endoplasmic reticulum in the pyramidal cell layer. But by P30 SK2 was almost exclusively expressed in the dendrites and spines. The level of SK2 at the postsynaptic density (PSD) also increased during development. In the adult, SK2 expression on the spine plasma membrane showed a proximal-to-distal gradient. Consistent with this redistribution and gradient of SK2, the selective SK channel blocker apamin increased evoked excitatory postsynaptic potentials (EPSPs) only in CA1 pyramidal neurons from mice older than P15. However, the effect of apamin on EPSPs was not different between synapses in proximal or distal stratum radiatum or stratum lacunosum-moleculare in adult. These results show a developmental increase and gradient in SK2-containing channel surface expression that underlie their influence on neurotransmission, and that may contribute to increased memory acquisition during early development.

Original languageEnglish (US)
Pages (from-to)1467-1480
Number of pages14
JournalHippocampus
Volume22
Issue number6
DOIs
StatePublished - Jun 2012

Keywords

  • Calcium channels
  • Development
  • Electron microscopy
  • Potassium channel

ASJC Scopus subject areas

  • Cognitive Neuroscience

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  • Cite this

    Ballesteros-Merino, C., Lin, M., Wu, W. W., Ferrandiz-Huertas, C., Cabañero, M. J., Watanabe, M., Fukazawa, Y., Shigemoto, R., Maylie, J., Adelman, J. P., & Luján, R. (2012). Developmental profile of SK2 channel expression and function in CA1 neurons. Hippocampus, 22(6), 1467-1480. https://doi.org/10.1002/hipo.20986