alpha-MSH-induced behavior: changes after diazepam and baclofen administration related with cyclic AMP levels

The present work was performed to evaluate the participation of the benzodiacepinic GABAA and GABAB components upon excessive grooming, locomotion, rearing, and stretching/yawning syndrome induced by the intracerebroventricularly alpha-MSH administration by using GABAA and GABAB agonists. It also aims at evaluating possible relation between changes in cAMP levels in caudate-putamen and accumbens nuclei and the behavioral responses. Injection of diazepam or baclofen reduced the total behavioral scores in a dose-related manner as well as the cAMP levels with respect to the control values (animals treated with artificial cerebrospinal fluid). When diazepam was tested in animals simultaneously injected with alpha-MSH, behavioral scores decreased with respect to those treated with the peptide alone. Cyclic AMP also decreased after combined treatment (MSH + diazepam).