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 recorded in lobules I-IV anterior and VII-IX posterior responded to this stimulus. In lobule V, generally considered to be the forelimb projection area, about a third of the 38 cells tested responded to hind foot movement. Cells in the anterior lobe typically exhibited different poststimulus patterns in response to foot flexion and extension while posterior 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 more laterally (2.7 mm of the midline) generally had longer response latencies than cells recorded more laterally (2.7-4.5 mm) in both lobes. The results illustrate a diffuse proprioceptive input to the cerebellar vermis which has different features in various cerebellar areas.