Referenced in: none

Automatically associated channels: Kv2.1

Title: Glutamate and N-acetylaspartylglutamate block HVA calcium currents in frog olfactory bulb interneurons via an mGluR2/3-like receptor.

Authors: J Bischofberger, D Schild

Journal, date & volume: J. Neurophysiol., 1996 Sep , 76, 2089-92

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8890318

Abstract
1. We investigated the glutamate-mediated modulation of voltage-activated calcium currents in cultured interneurons of the olfactory bulb of Xenopus laevis, with the use of standard patch-clamp whole-cell recordings. 2. Glutamate and N-acetylaspartylglutamate (NAAG) activated (2S,1'R,2'R,3'R)-2-(2,3-dicarboxy-cyclopropyl)glycin-sens iti ve metabotropic glutamate receptors at olfactory bulb interneurons and thereby inhibited calcium influx through presynaptic voltage-gated calcium channels. 3. The glutamate- or NAAG-mediated blockage of calcium channels showed indistinguishable dose-response curves, with K1/2 = 388 and 350 nM for glutamate and NAAG, respectively. At saturating concentrations of glutamate or NAAG, approximately 40% of the maximum calcium currents were blocked. 4. It is concluded that glutamate, which excites interneurons at olfactory bulb reciprocal synapses, also causes a reduction of gamma-aminobutyric acid-mediated feedback inhibition at these synapses by activating a metabotropic-glutamate-receptor-2/3-like receptor.