Figure 1.

Schematic diagram showing experimental arrangements. Climbing fiber field potentials were recorded from the paravermal cerebellar cortex (CC) (lobule V, zones C1 and C3). Ascending climbing fiber pathways (SOCPs) were activated by electrical stimuli delivered to the SR nerve in the ipsilateral forelimb, and the afferent nerve volley was monitored proximally. Descending climbing fiber pathways (COCPs) were activated by electrical stimuli delivered to the contralateral CP (all animals) or contralateral pyramidal tract (PT¹) (animal ME1), and the tract volley was monitored caudally (PT²) (animal BW5). EMG activity was monitored from triceps brachii or cleidobrachialis in the ipsilateral forelimb. See Materials and Methods for additional details.