[Participation of thalamic nuclei in the elaboration of conditioned avoidance reflexes of rats. IV. Lesions of the nucleus reuniens].

The elaboration of conditioned avoidance reflexes in a Y-maze and in the jumping test was scarcely influenced by lesion of the n. reuniens of the thalamus in hooded rats. The increase of intertrialreactions in the jumping test after such lesions in contrast to the control group indicates changes in the regulation of motivational processes. After additional lesion of the n. rhomboideus neither the conditioned avoidance nor the unconditioned escape reaction were elaborated in the jumping test.