Pharmacological Alterations of Anxious Behaviour in Mice Depending on Both Strain and the Behavioural Situation

A previous study comparing non-emotive mice from the strain C57BL/6/ByJ with ABP/Le mice showed ABP/Le to be more anxious in an open-field situation. In the present study, several compounds affecting anxiety were assayed on ABP/Le and C57BL/6/ByJ mice using three behavioural models of anxiety: the elevated plus-maze, the light-dark discrimination test and the free exploratory paradigm. The compounds used were the full benzodiazepine receptor agonist, chlordiazepoxide, and the antagonist, flumazenil, the GABAA antagonist, bicuculline, the full 5-HT1A agonist 8-OH-DPAT, and the mixed 5-HT1A/5-HT1B agonist, RU 24969. Results showed the effect of the compounds to be dependent on both the strain and the behavioural task. Several compounds found to be anxiolytic in ABP/Le mice had an anxiogenic effect on C57BL/6/ByJ mice. More behavioural changes were observed for ABP/Le in the elevated plus-maze, but the clearest findings for C57BL/6/ByJ mice were observed in the light-dark discrimination apparatus. These data demonstrate that anxious behaviour is a complex phenomenon which cannot be described by a single behavioural task nor by the action of a single compound

Influence of Griffonia simplicifolia on male sexual behavior in rats: Behavioral and neurochemical study

The seeds of Griffonia simplicifolia Baill. are rich in 5-HIP (5-hydroxytryptophan), a direct precursor of the neurotransmitter serotonin. In the present study we investigated the influence of the plant extract on male sexual behavior. The seed extract was orally administered to Sprague-Dawley male rats at three dose levels (25, 50 and 100 mg/kg) both acutely and subchronically (daily for 9 days). Mating test with receptive female rats was performed 60 min after the acute treatment or the last dose when repetitively administered. Mount, intromission and ejaculation latencies and post-ejaculatory interval were recorded. Food intake and body weight were measured over the 9-day period of treatment. Microdialysis technique was used to detect the extracellular levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in rat brain following the acute administration of the extract dosed at 100 mg/kg. The acute treatment significantly increased mount latency (at any dosage), intromission and ejaculation latencies (at 100 mg/kg) and post-ejaculatory interval (at 50 and 100 mg/kg). On the contrary the subchronic treatment failed to exert a significant influence on copulatory behavior. The daily administration of the extract dosed at 50 and 100 mg/kg for 9 days significantly reduced food intake and body weight. Finally in the microdialysis experiments we found a dramatic increase in 5-HT and its metabolite 5-HIAA. (C) 2011 Elsevier GmbH. All rights reserved