SENSORY RESPONSES TO PASSIVE HINDLIMB JOINT ROTATION IN THE CEREBELLAR CORTEX OF THE CAT

We recorded from Purkinje cells in the anterior and posterior lobes of the cerebellar vermis in anesthetized cats during passive flexion and extension of the ipsilateral hind foot. Nearly 60% of the 302 cells r ecorded in lobules I-IV anterior and VII-IX posterior responded to thi s stimulus. In lobule V, generally considered to be the forelimb proje ction area, about a third of the 38 cells tested responded to hind foo t movement. Cells in the anterior lobe typically exhibited different p oststimulus patterns in response to foot flexion and extension while p osterior cells usually had the same response to these stimuli. We also noted that cells recorded in the medial vermis (within 2.7 mm of the midline) generally had longer response latencies than cells recorded m ore laterally (2.7-4.5 mm) in both lobes. The results illustrate a dif fuse proprioceptive input to the cerebellar vermis which has different features in various cerebellar areas.