Figure 14.

(A–C) show the restricted spatial pattern of excitatory (dark stippling) and inhibitory (light hatching) Purkinje cell responses following peripheral stimulation in three experiments. The stimulus activated only granule cells beneath the region of excitatory PC responses. (D) shows the expected pattern of activation if parallel fibers drove Purkinje cell responses. (E) Original drawing from Llinas (1982) illustrating the hypothesis that synapses associated with the ascending segment of the granule cell axon drove the excitatory Purkinje cell responses. Reprinted with permission from Bower and Woolston (1983).