ELECTROGRAPHIC ANALYSIS OF THE DYNAMICS O F FUNCTIONAL-STATE CHANGE OF THE RAT-BRAIN AFTER DESTRUCTION OF THE LOCUS-CERULEUS

Bilateral destruction of the Locus coeruleus in rats was carried out b y means of 6-hydroxydopamine injections. Sham-operated animals served as control ones. Electrical activity was recorded in the region of the Locus coeruleus, the dorsal hippocampus, and in the caudatus-putamen complex. Beginning from the second week after surgery in experimental rats was observed a generalization of the theta-rhythm (7-9 Hz) in ele ctrical activity of the Locus coeruleus, hippocampus and the caudatus- putamen complex during orienting-exploratory activity. At the same tim e such a rhythm was enhanced in animals with motor and orienting-explo ratory agitation. In comparison to the sham-operated animals there wer e no changes in expression in the electrical activity of the subcortic al structures of the rhythm of 5-6 Hz, accompanying immobilization sta te as well as that of 9-11 Hz, accompanying teeth chattering. The dyna mics of changes of subcortical electrical activity of rats after the L ocus coeruleus destruction may serve an index of the functional state of the animals under the conditions of noradrenergic deficiency. Chang es of the brain electrical activity and behaviour of the animals revea led are considered to be a consequence of a relative enhancement of th e central serotoninergic regulation of the subcortical structures bein g caused by a weakening of noradrenergic influences.