Approach-escape interactions in rat brain

Animals with electrodes implanted at tegmental escape points and at hypothalamic approach points were tested for positive reinforcement during simultaneous negative stimulation, and for escape behavior during simultaneous positive stimulation.

Abstract

Animals with electrodes implanted at tegmental escape points and at hypothalamic approach points were tested for positive reinforcement during simultaneous negative stimulation, and for escape behavior during simultaneous positive stimulation. The test of positive reinforcement was made by presenting a correlated hypothalamic stimulus after each lever response, during a 2-min period, while a constant train of stimulation was being applied to a negative reinforcing point in tegmentum. The test of negative reinforcement was made by presenting repeated 1/2-sec trains of tegmental stimulation at a rate of 1/sec and interrupting this sequence for 4 sec after each lever response, during a 2-min period, while a constant train of stimulation was being applied to the positive reinforcing point in lateral hypothalamus. The constant negative train impeded and sometimes inhibited completely the positively reinforced behavior. The constant positive train, however, far from impeding the escape response, regularly facilitated the negatively reinforced behavior. The data were interpreted on the theory of a one-way inhibition from tegmental escape points to the hypothalamic approach one.