Referenced in: none

Automatically associated channels: Kir6.2

Title: N-Type calcium channels in the developing rat hippocampus: subunit, complex, and regional expression.

Authors: O T Jones, G M Bernstein, E J Jones, D G Jugloff, M Law, W Wong, L R Mills

Journal, date & volume: J. Neurosci., 1997 Aug 15 , 17, 6152-64

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/9236227

Abstract
The expression of multiple classes of voltage-dependent calcium channels (VDCCs) allows neurons to tailor calcium signaling to functionally discrete cellular regions. In the developing hippocampus a central issue is whether the expression of VDCC subtypes plays a role in key phases such as migration and synaptogenesis. Using radioligand binding and immunoblotting, we show that some N-type VDCCs exist before birth, consistent with a role in migration; however, most N-VDCC subunit expression is postnatal, coinciding with synaptogenesis. Immunoprecipitation studies indicate that the increased expression of N-VDCCs in early development occurs without subunit switching because there is no change in the fraction of beta3 subunits in the N-VDCC alpha1B-beta3 heteromers. Fluorescence imaging of cell surface N-VDCCs during this period reveals that N-VDCCs are expressed on somata before dendrites and that this expression is asynchronous between different subfields of the hippocampus (CA3-CA4 before CA1-CA2 and dentate gyrus). Our data argue that N-VDCC expression is an important cue in the genesis of synaptic transmission in discrete hippocampal subfields.