8-OH-DPAT specifically enhances feeding behaviour in mice: evidence from behavioural competition.
The behavioural specificity of the hyperphagic effects of 8-OH-DPAT is a controversial issue. The present study addressed this question through the introduction of behavioural competition. Feeding behaviour in male mice was assessed under both basal (free-feeding) and social conflict conditions. Since, in the latter condition, defence and escape are prepotent responses, elicitation of feeding would be indicative of a specific treatment effect on mechanisms controlling food intake. Results showed that 8-OH-DPAT enhanced basal feeding duration (at doses of 0.05-0.50 mg/kg) and also elicited feeding in intruder mice during encounters with aggressive resident conspecifics (at doses of 0.10-0.50 mg/kg). As the 5-HT3 antagonist GR38032F (1.0-2.0 mg/kg) enhanced feeding only under basal conditions, the effect of 8-OH-DPAT cannot readily be attributed to anxiety reduction. Finally, diazepam (1.0-2.0 mg/kg) produced a similar profile to that of 8-OH-DPAT, suggesting that the hyperphagic effects of the 5-HT1A agonist are not pharmacologically specific.
Shepherd
J K
JK
Department of Psychology, University of Leeds, UK.
Rodgers
R J
RJ
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D003163:Competitive Behavior / Q000187:drug effects*; D003220:Conflict, Psychological; D003975:Diazepam / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009281:Naphthalenes / Q000494:pharmacology*; D017294:Ondansetron; D012919:Social Behavior; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D007093:Imidazoles; D009281:Naphthalenes; D013764:Tetrahydronaphthalenes; D017294:Ondansetron; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D003975:Diazepam