The discharges of cerebellar Golgi cells during locomotion in the cat.

Abstract

SUMMARY1. Extracellular recordings have been obtained from 134 units in the paravermal cortex of lobule V in the anterior lobe of the cerebellum in free-to-move cats. Each unit discharged action potentials in a characteristic pattern with no complex spikes. Previous investigators have described such discharges and have assigned them to Golgi cells. We provide further evidence to support this identification.2. In cats which were sitting quietly, each putative Golgi cell discharged tonically at a low rate (overall mean (±S.D.) was 14-5+7-3 spikes/s). Eighty-one of the neurones were also recorded during steady walking on a moving belt and the discharge rate then averaged 17-7 (S.D. + 19-4) spikes/s.3. All eighty-one putative Golgi cells discharged rythmically during locomotion. Many different patterns of discharge were seen but as a population the neurones were most active in early stance and at the onset of the swing phase of the step cycle in the ipsilateral forelimb.4. Over a range of different walking speeds (0 5-09 m/s) and of different uphill inclines (0-25 deg), putative Golgi cells discharged with similar patterns and rates, despite large changes in the vigour of the locomotor movements and in the amplitude of limb muscle electromyograms.

Characteristics of Responses of Golgi Cells and Mossy Fibers to Eye Saccades and Saccadic Adaptation Recorded from the Posterior Vermis of the Cerebellum

“…It should however be noted that GCs largely outnumber the Lugaro cells in the granular layer [the ratio of Golgi to Lugaro cells is ϳ67/15 in the mouse cerebellum according to Simat et al (2007)]. Finally, unlike previously reported (Edgley and Lidierth, 1987), we did not find that PC action potentials were shorter than those of GCs (Fig. 3D) were.…”

“…The axonal plexus of individual GCs are known to branch within generally nonoverlapping parasagittal planes (Barmack and Yakhnitsa, 2008). Combined with the heterogeneity of their discharge patterns, this suggests, as previously speculated by Edgley and Lidierth (1987), that subpopulations of thousands of GrCs organized in sagittal zones are under different patterns of inhibitory control. van Kan et al (1993) reported that most MFs responded reciprocally to extension and flexion movements and exhibited strong device specificity (showed preference for shoulder, elbow, wrist, or finger manipulation), whereas GCs fired identically for both flexion and extension, and lacked device specificity.…”

“…The cell-to-cell variability of movement-related discharges in GCs was also observed for various eye and head movements (Miles et al, 1980) and forelimb manipulations (van Kan et al, 1993) in the monkey, as well as during cat locomotion (Edgley and Lidierth, 1987). This was vexingly not the case for electrical and somatosensory stimuli of vibrissal pads and limbs in rats (Vos et al, 1999b;Holtzman et al, 2006), in which the evoked GC responses were more stereotypical.…”

“…van Kan et al (1993) reported that most MFs responded reciprocally to extension and flexion movements and exhibited strong device specificity (showed preference for shoulder, elbow, wrist, or finger manipulation), whereas GCs fired identically for both flexion and extension, and lacked device specificity. Similarly, Edgley and Lidierth (1987) stated that the majority of GCs were responsive to stimuli of both forelimbs of the cat, and the eye saccade-related responses of MFs recorded in the flocculus (Miles et al, 1980) or the OMV (Kase et al, 1980;Ohtsuka and Noda, 1992) generally showed strong directional preference. Finally, electrical and tactile stimuli of the rat face or limbs (Vos et al, 1999b;Holtzman et al, 2006) revealed that responses in GCs could be elicited from widespread areas.…”

“…8 A, B). The study by Edgley and Lidierth (1987) is the only other one to our knowledge to examine the specificity of GCs to movement metrics. In line with our own results, they reported that different speeds of locomotion and platform inclination angles resulted in unaltered timing patterns and discharge rates of most GCs.…”