DIFFERENTIAL EFFECTS OF CHOLINERGIC AGONISTS ON SELF-STIMULATION AND ESCAPE BEHAVIOR

¹ Michigan Neuropsychopharmacology Research Program, Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, and Lafayette Clinic, Detroit, Michigan

The purpose of these experiments was to compare the effects of cholinergic agonists on approach behavior induced by electrical stimulation of lateral posterior hypothalamus with those on escape behavior induced by electrical stimulation of midbrain tegmentum. Adult male albino rats were prepared with chronic bipolar electrodes for brain stimulation. Conventional behavioral techniques were used to record approach or escape responses. After suitable training sessions, various cholinergic agonista and antagonists were given s.c. In addition, total brain acetylcholine and acetylcholinesterase activity was determined and correlated with the induced behavioral changes. It was found that escape behavior is not depressed by cholinergic agonists in doses which produce profound depression of self-stimulation behavior.