title: Anxiogenic-like effect of glycine and D-serine microinjected into dorsal periaqueductal gray matter of rats.
abstract: The glutamatergic system of the dorsal periaqueductal gray matter (DPAG) has been implicated in anxiety. This study shows that microinjections of glycine (GLY) or D-serine (D-SER), into the DPAG of rats, dose-dependently reduced the number of entries and the time spent on open arms of an elevated plus-maze (EPM), an established animal model for measuring anxiety-related behavior. This anxiogenic-like effect was greatest following DPAG application of either 80 nmol GLY or 160 and 320 nmol D-SER. Microinjections of these same amino acid doses outside the DPAG, or of L-serine (320 nmol) inside the DPAG, produced neither of these pro-anxiety effects. The current results suggest that, in vivo, the GLY modulatory site of N-methyl-D-aspartate receptors is not fully saturated, and further substantiate a role for the DPAG excitatory amino acid system in anxiety.
authors.affiliation: Departamento de Farmacologia/CCB, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Schmitt
authors.forename: W
authors.initials: W
authors.lastname: Coelho
authors.forename: A S
authors.initials: AS
authors.lastname: Lopes-de-Souza
authors.forename: F S
authors.initials: FS
authors.lastname: Guimarães
authors.forename: A P
authors.initials: AP
authors.lastname: Carobrez
mesh_terms: D000818:Animals; D001007:Anxiety / Q000139:chemically induced* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D005998:Glycine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008845:Microinjections; D010487:Periaqueductal Gray / Q000033:anatomy & histology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism; D012694:Serine / Q000008:administration & dosage / Q000494:pharmacology*; D013237:Stereoisomerism
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D012694:Serine; D005998:Glycine