Anxiolytic effect of intra-amygdala injection of midazolam and 8-hydroxy-2-(di-n-propylamino)tetralin in the elevated T-maze.
The effects of intra-amygdala injection of midazolam (20 nmol) and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 8 and 16 nmol) were investigated in rats submitted to the elevated T-maze, a new animal model of anxiety. This test allows the measurement, in the same rat, of conditioned and unconditioned fear/anxiety responses. Both drugs impaired inhibitory avoidance of the open arms of the T-maze (task representing conditioned fear), indicating an anxiolytic effect, but did not change escape performance from one of the open arms (representing unconditioned fear). The results further implicate gamma-aminobutyric acid (GABA)/benzodiazepine and serotonergic systems within the basolateral/lateral amygdala in the modulation of conditioned anxiety responses.
Zangrossi
H
H
Faculdade de Medicina de Ribeirão Preto, Departamento de Farmacologia, University of São Paulo-Ribeirão Preto, SP, Brazil. zangross@usp.br
Viana
M B
MB
Graeff
F G
FG
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000679:Amygdala; D000704:Analysis of Variance; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy; D001362:Avoidance Learning / Q000187:drug effects*; D003213:Conditioning, Psychological / Q000187:drug effects; D004195:Disease Models, Animal; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008845:Microinjections; D008874:Midazolam / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D014151:Anti-Anxiety Agents; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D008874:Midazolam