Functional linkage between the electrical activity in the vermal cerebellar cortex and saccadic eye movements

Abstract

The temporal relation between the onset of electrical activity of Purkinje cells and the occurrence of rapid eye movements was studied. Experiments were performed in unanesthetized animals, the recordings being made under direct vision through the use of a chronically implanted teflon sleeve. The following results were obtained. 1. Correlation between the activity of Purkinje cells and eye movements indicates that Purkinje cell firing in vermal lobules VI and VII precedes eye movement by 11-12 msec, peak activity corresponding to the time of onset of eye movement. 2. This eye movement related activity of Purkinje cells occurred regardless of the direction of the eye movements but some cells showed directional biases. Best correlation between eye movement and Purkinje cell activity was found with fast eye movements toward the right regardless of recording side. 3. Electrical activity of Purkinje cells was mainly related to saccades. Slow eye movement modulation, although probably present, was not studied in detail. 4. In those cells where an extensive set of measurements could be made, Purkinje cell firing was found to be inversely proportional to the amplitude of the eye movement, small movements being preceded by highest Purkinje cell activity. The present results suggest that cerebellar vermis responds prior to the generation of eye movement and may probably serve to control eye movements in a ballistic manner.

Functional mapping of the human cerebellum with positron emission tomography.

“…We detected only one activated zone in each cerebellar hemisphere during the finger-movement task; yet four discrete foci of activation could be anticipated from the studies described above (18)(19)(20)(21)(22)(23)(24)(25)(26)(27). The intense, ipsilateral hemispheric increase in regional blood flow occurring during finger movement and (to a lesser extent) during finger stimulation is best attributed to activity within the large cortical receiving area in the anterior lobe (lobules IV and V).…”

“…Neurons active during visual stimulation (18) and oculomotor activity (21,26,27) are most dense in lobule VI (declive and simplex), which in man would be expected to lie 1-2 cm posterior to the first forelimb receiving zone of Snider and Stowell, abutting the midsagittal plane.…”

“…The paramedian-lobule responses described by Snider and (18,20,(22)(23)(24)(25) and the eyes (18,21,(26)(27). Lobules of the anterior lobe are in heavy outline; underlying nuclei are in dashed outline.…”

“…Sci. USA 82 (1985) Stowell (18) (18,21,26,27). Despite a mean separation of <1 cm (i.e., <1 FWHM) between the regions responding to finger movement and that responding to eye movement, these regions could be discriminated because the two tasks were performed during different scans (i.e., sequentially rather than simultaneously).…”

Deficits in Saccades and Fixation During Muscimol Inactivation of the Caudal Fastigial Nucleus in the Rhesus Monkey

“…Neurons in the lobules VIc and VII (Helmchen and Büttner 1995;Kase et al 1980;Llinas and Wolfe 1977;Ohtsuka and Noda 1995;Thier et al 2000) and in the cFN (cat: Gruart and Delgado-Garcia 1994;monkey: Fuchs et al 1993;Helmchen et al 1994;Hepp et al 1982;Kleine et al 2003;Ohtsuka and Noda 1991) display saccade-related bursts of activity. Although most of these neurons also show a steady firing rate during intersaccadic intervals Helmchen et al 1994;Kleine et al 2003;Ohtsuka and Noda 1991), the dysmetria observed during muscimol injection in the cFN is interpreted as resulting from the suppression of the saccaderelated bursts.…”