Effects of Adrenalectomy and Treatments with ACTH and Glucocorticoids on Isolation-Induced Aggressive Behavior in Male Albino Mice

Abstract

Publisher Summary This chapter presents several experiments to show the effects of adrenalectomy and treatments with adrenocorticotropic hormone (ACTH) and glucocorticoids on isolation-induced aggressive behavior in male albino mice. It is well-known that isolation induces fighting behavior in laboratory mice and that the longer the period of isolation, the more intense the behavior. It is apparent that, as well as being influenced by the “stress” of behavioral interactions, the hormones of the pituitary-adrenocortical axis (ACTH and glucocorticoids) can have a marked and rather specific influence on some social behaviors in rodents. The results confirm that modulation of isolation-induced fighting by the pituitary—adrenocortical axis is a complex phenomenon, strongly influenced by the animal's prior experience and the type of test employed. The fact that ACTH causes both adrenalectomized and mock operated animals to be subordinate with respect to mock injected animals, suggests a direct action rather than an effect mediated via the production of adrenal steroids. It was concluded that both ACTH and glucocorticoids may have a direct action on aggressive behavior and that part of this influence may be by affecting the “attackability” of the treated animal.