title: Inactivation kinetics of voltage-gated calcium channels in glutamatergic neurons are influenced by SNAP-25.
abstract: SNAP-25 forms part of the SNARE core complex that mediates membrane fusion. Biochemical and electrophysiological evidence supports an accessory role for SNAP-25 in interacting with voltage-gated calcium channels (VGCCs) to modulate channel activity. We recently reported that endogenous SNAP-25 negatively regulates VGCC activity in glutamatergic neurons from rat hippocampal cultures by shifting the voltage-dependence of inactivation of the predominant P/Q-type channel current in these cells. In the present study, we extend these findings by investigating the effect that manipulating endogenous SNAP-25 expression has on the inactivation kinetics of VGCC current in both glutamatergic and GABAergic cells recorded from 9-13 DIV cultures. Silencing SNAP-25 in glutamatergic neurons significantly slowed the inactivation rate of P/Q-type VGCC current whereas alterations in SNAP-25 expression did not alter inactivation rates in GABAergic neurons. These results indicate that endogenous SNAP-25 plays an important role in P/Q-type channel regulation in glutamatergic neurons.
authors.affiliation: Department of Physiology, University of Otago, Dunedin, New Zealand. steven.condliffe@otago.ac.nz
authors.forename: Steven B
authors.initials: SB
authors.lastname: Condliffe
authors.forename: Michela
authors.initials: M
authors.lastname: Matteoli
mesh_terms: D000818:Animals; D020865:Calcium Channels, P-Type / Q000235:genetics / Q000378:metabolism*; D020907:Calcium Channels, Q-Type / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D015870:Gene Expression; D020868:Gene Silencing; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D015640:Ion Channel Gating / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics / Q000378:metabolism*
chemical_list: D020865:Calcium Channels, P-Type; D020907:Calcium Channels, Q-Type; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25