title: Activation of 5-HT1A receptors in the rat basolateral amygdala induces both anxiolytic and antipanic-like effects.
abstract: The relevance of 5-HT1A and 5-HT2C receptors of the basolateral nucleus of the amygdala (BLA) in the mediation of anxiety-related defensive responses has long been acknowledged. Whereas strong evidence supports that activation of the latter receptors provokes anxiety, conflicting findings have been reported on the role played by the former binding site. In this study we further investigated the involvement of 5-HT1A receptors (5-HT1A-Rs) in the regulation of anxiety- and panic-related defensive behaviors. The results showed that intra-BLA injection of the 5-HT1A-R agonist 8-OH-DPAT (0.4-16nmol) in male Wistar rats impaired the acquisition of inhibitory avoidance in the elevated T-maze, increased the percentage of time spent in the lit compartment of the light-dark transition model and enhanced the number of punished drinking events in the Vogel conflict test, all changes compatible with an anxiolytic effect. This agonist also impaired escape expression in the elevated T-maze, suggestive of a panicolytic-like effect. 8-OH-DPAT-induced changes in the elevated T-maze and light-dark tests were blocked by previous local administration of the 5-HT1A-R antagonist WAY-100635 (0.37nmol) and were also observed after intra-BLA microinjection of the benzodiazepine receptor agonist midazolam (10-40nmol). Thus, stimulation of 5-HT1A-Rs in the BLA causes both anxiolytic- and panicolytic-like effects, what may have implications for the pathophysiology and treatment of generalized anxiety and panic disorders.
authors.affiliation: Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Christiana Villela de Andrade
authors.initials: CV
authors.lastname: Strauss
authors.forename: Maria Adrielle
authors.initials: MA
authors.lastname: Vicente
authors.forename: Helio
authors.initials: H
authors.lastname: Zangrossi
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000633:toxicity; D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D001007:Anxiety / Q000139:chemically induced / Q000378:metabolism*; D003623:Dark Adaptation / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004924:Escape Reaction / Q000187:drug effects; D005106:Exploratory Behavior / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008845:Microinjections; D008874:Midazolam / Q000494:pharmacology; D016584:Panic Disorder / Q000139:chemically induced / Q000378:metabolism*; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000633:toxicity; D014868:Water Deprivation
chemical_list: D014151:Anti-Anxiety Agents; D010879:Piperazines; D011725:Pyridines; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D008874:Midazolam