Cerebellar nucleus lesions dissociate alpha conditioning from alpha responses in rabbits

This experiment compared the effects of unilateral lesions of the cerebellar nuclei and control lesions of the cerebellar cortex on alpha responses, alpha conditioning, and classical conditioning in the rabbit eyelid conditioning paradigm. Lesions of the dentate-interpositus (DI) region of the cerebellar nuclei abolished retention of conditioned responses to an auditory conditioned stimulus (CS), and prevented acquisition of conditioned alpha responses to a dim proximal light CS, but did not diminish alpha responses to a bright proximal light. These results indicate that the DI region is essential to both alpha conditioning and classical conditioning of eyelid responses, hut not to alpha responses, and suggest that both forms of conditioning are mediated by a common anatomical substrate that is distinct from the anatomical substrate of alpha responses.