Citation

Haller J, Makara GB, Kovács JL. Psychopharmacology 1996; 126(4): 345-350.

Affiliation

Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.

Copyright

(Copyright © 1996, Holtzbrinck Springer Nature Publishing Group)

DOI

unavailable

PMID

8878351

Abstract

The effects of three alpha 2 adrenoceptor blockers (idazoxan, yohimbine and CH-38083) on isolation-induced aggressive behavior was studied in male mice. The three drugs produced different behavioral profiles. Idazoxan reduced aggressiveness dose-dependently by decreasing the duration of offensive/aggressive interactions and increasing the duration of defensive behaviors. The other two drugs produced only parts of the dual action of idazoxan: yohimbine affected mainly defensive behaviors, while CH-38083 affected only the time spent with fighting. Saline injections per se also influenced behavior and, in contrast to alpha 2 adrenoceptor blockers, induced an increase in aggressiveness. These results are different from those previously obtained in rats, which show bell-shaped dose-response curves in response to alpha 2 adrenoceptor blockers (small doses increased, while large doses decreased aggression). It is postulated that the strong behavioral reaction of mice to the injection per se may mask the aggression-heightening effects of small doses of alpha 2 adrenoceptor blockers in this species. A theory is also presented regarding the complexity of adrenoceptor interactions when both pre-, and postsynaptic alpha 2 adrenoceptors are blocked.

Language: en