Intracranial self-stimulation and escape by EEG-derived instrumental responses in cerveau isolé rats

Abstract

In 14 of the 25 unanesthetized postcollicular, pretrigeminal cerveau isolé rats studied, intracranial self-stimulation or escape, or both, were demonstrated using EEG-derived instrumental responses. Stimulus trains (0.5-sec, 40-cps trains of 0.5-msec cathodal pulses at 600 μA) were delivered in a continuous reinforcement schedule in series of tests for each of 55 diencephalic and mesencephalic sites. Medial forebrain bundle stimulation consistently elicited self-stimulation, but never evoked escape. Stimulation of known aversive regions, lateral reticular formation, medial lemniscus, and meninges, elicited escape, but not self-stimulation. Both self-stimulation and escape were obtained by two types of EEG responses: high and low voltage, which triggered reinforcements when EEG amplitude increased and decreased, respectively. These data extend previous concepts of the integrative capability of cerveau isolé animals to include phenomena related to reward, pain, and neural plasticity. The cerveau isolé technique presented may offer significant advantages for several types of experiments for which the paralyzed encephalé isolé preparation has been the traditional choice. © 1977, Psychonomic Society, Inc.. All rights reserved.