title: Detection of gamma-aminobutyric acid-induced glutamate release in acute mouse hippocampal slices with a patch sensor.
abstract: gamma-Aminobutyric acid (GABA)-stimulated release of L-glutamate from various neuronal regions of acute mouse hippocampal slices was detected with a patch sensor that responds to L-glutamate at the sub-micromolar level. The response of the patch sensor to L-glutamate was evaluated in terms of an integrated current. The integrated current increased with the concentration of L-glutamate ranging from 0.50 to 5.0 microM. By using the patch sensor, GABA-induced L-glutamate release from acute mouse hippocampal slices was detected. The effect of antagonists for GABA(A) and GABA(B) receptors on the L-glutamate release was also investigated. The GABA (25 microM) stimulation induced the release of L-glutamate via GABA(A) receptor in the CA1 region, but GABA did not induce L-glutamate release in the CA3 region. However, in the presence of the GABA(B) receptor antagonist (3-aminopropyl)(diethoxymethyl)phosphinic acid (CGP-35348), release of L-glutamate in the CA3 region was evoked by GABA stimulation. The glutamate release was completely suppressed when both GABA(A) and GABA(B) receptor were inhibited. The current results show that the glutamate release in the CA3 region occurs via a GABA(A) pathway when GABA(B) receptors are inhibited.
authors.affiliation: Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo, Japan.
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Shimane
authors.forename: Kaori
authors.initials: K
authors.lastname: Miyagawa
authors.forename: Masao
authors.initials: M
authors.lastname: Sugawara
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002462:Cell Membrane / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D018408:Patch-Clamp Techniques / Q000379:methods; D011963:Receptors, GABA-A / Q000378:metabolism; D018080:Receptors, GABA-B / Q000378:metabolism; D017470:Receptors, Glutamate / Q000378:metabolism*; D012107:Research Design; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000494:pharmacology
chemical_list: D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D017470:Receptors, Glutamate; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid