The GABAergic effect of low doses of lorazepam on social behavior

• Published in: Aggressive behavior 2002, Vol.28 (3), p.248-256
• Main Authors: Pérez Conchillo, María, Martínez-Sanchis, Sonia, Salvador, Alicia, Simón, Vicente M.
• Format: Article
• Language: English
• Subjects: aggression; Behavioral psychophysiology; benzodiazepines; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; lorazepam; male mice; Neurotransmission and behavior; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Ro 15-1788; social behavior
• ISSN: 0096-140X; 1098-2337
• DOI: 10.1002/ab.90025

The aim of this work was to test the antiaggressive effects of lorazepam and to determine whether these effects were mediated by benzodiazepine receptors. In a first experiment, male mice were injected with lorazepam in a range of low doses (0.05, 0.1, 0.2, and 0.6 mg/kg) or saline solution. In a second experiment, 1 mg/kg of Ro 15‐1788, a benzodiazepine receptor antagonist, and a saline solution were injected before the behavioral test. Results showed that 0.6 mg/kg of lorazepam was the only dose that decreased the total duration of threat (P < .01) and social investigation (P < .05) and that 1 mg/kg of Ro 15‐1788 had no effects. In the third experiment, animals received two injections: 0.6 mg/kg of lorazepam plus 1 mg/kg of Ro 15‐1788, 0.6 mg/kg of lorazepam plus saline solution, or saline solution plus saline solution. Those treated with lorazepam and saline solution spent less time digging (P < .001), threatening (P < .001), and attacking (P < .05) and more time avoiding the opponent (P < .01) or being immobile (P < .001) than the controls. Ro 15‐1788 was successful in completely antagonizing the behavior modulated by lorazepam. Aggr. Behav. 28:248–256, 2002. © 2002 Wiley‐Liss, Inc.