| Abstract: | The behavioral profiles generated by a benzodiazepine (BDZ) agonist (diazepam), an “inverse” agonist (β-carboline-3-carboxylate ethyl ester, βC-3-CEE), and dihydro-(DHβCs) and tetrahydro-β-carbolines (THβCs) were investigated on aggressive isolated mice using a computerized ethopharmacological technique. Augmentation of intraspecific sociability with a concurrent reduction of aggression are characteristic features of diazepam's effects, whereas βC-3-CEE exerts the opposite effects. βC-3-CEE countered the prosocial activity of diazepam and had intrinsic activities on intraspecific behaviour. Some DHβCs (harmalol and 6-methoxy-harmalan) and THβCs (1-methyl-6-hydroxy-THβC and tetrahydronorharmane) may exacerbate aggression at low (BDZ-negative) doses (1 mg/kg), and inhibit such behavior at higher (serotonin-positive) doses (10-15 mg/kg). The ethological profiles of DHβCs were different from the profiles of THβCs. Differences in ethological profiles of βC-3-CEE, DHβCs, and THβCs seem to reflect the neurochemical (mainly BDZ-and serotonergic) properties of these substances. |
