Wf. Supple et Bs. Kapp, THE ANTERIOR CEREBELLAR VERMIS - ESSENTIAL INVOLVEMENT IN CLASSICALLY-CONDITIONED BRADYCARDIA IN THE RABBIT, The Journal of neuroscience, 13(9), 1993, pp. 3705-3711
The effects of lesions of the cerebellum on the acquisition and retent
ion of aversive Pavlovian conditioned bradycardia were examined in rab
bits. Lesions of the anterior cerebellar vermis severely attenuated th
e acquisition of simple conditioned bradycardia without disrupting bas
eline heart rate (HR), or unconditioned HR responses. Also, lesions of
the vermis performed after the acquisition of conditioned bradycardia
eliminated evidence of prior conditioning. Bilateral lesions of the c
erebellar hemispheres did not affect conditioned or unconditioned HR r
esponses. These results were interpreted to indicate that anterior ver
mis lesions specifically disrupted part of an essential conditioned re
sponse pathway without interfering with the neural circuits that media
te unconditioned HR responding. These lesion data, coupled with recent
electrophysiological evidence of learning-related changes in neuronal
activity within the anterior vermis of the fear-conditioned rabbit, s
uggest that the anterior cerebellar vermis is critically involved in t
he acquisition and retention of this rapidly learned autonomic conditi
oned response.