Purkinje cell activity in the floccular middle-zone during optokinetic and vestibular eye movements in cats

1. Oculomotor responses to microstimulation of the cerebellar vermis of macaque monkeys were investigated by using a magnetic search-coil method. 2. The oculomotor responses were conjugate eye movements with an ipsilateral horizontal component. Analyses of amplitude-velocity and amplitude-duration relationships revealed that the peak eye velocities and the durations of the responses were comparable to those of saccadic eye movements. 3. Systematic mapping with microstimulation disclosed that the region in the cerebellar vermis that yielded saccades with weak stimulus currents was confined to lobule VII in five monkeys but included a part of folium VIc in the other four monkeys. This region coincided with the distribution of the saccade-related neural activity observed in the present study and also corresponded to the vermal folia from which we recorded the burst mossy-fiber units and the oculomotor Purkinje cell activity. 4. The oculomotor vermis was defined as that region of the cerebellar vermis that met the following criteria: 1) saccades were evoked with low-intensity microstimulation (with currents less than 10 microA); 2) vigorous saccade-related neural activity was present; and 3) Purkinje cell discharges were modulated with eye movements. The oculomotor vermis was more circumscribed and located more posteriorly than the vermal cortex explored in previous microstimulation experiments on monkeys. 5. Microstimulation of the oculomotor vermis evoked more or less curved saccades in oblique directions. The horizontal and vertical components were not simultaneous in some saccades: the shorter component started later or ended earlier than the other component and their peak velocities were not always synchronous. 6. The amplitude of the saccade depended on stimulus parameters; microstimulation with 10-12 pulses within a period of approximately 20 ms (500-600 Hz) was shown to be optimal. When the pulses were applied to the white matter or to the granular layer, a stimulus current of 10 microA was sufficient to evoke saccades. When the molecular layer was stimulated, evoked saccades were smaller and frequently curved, and an increase in the stimulus current changed either the initial direction or the trajectory of the saccade. 7. When the stimulus current was carefully controlled and maintained near the threshold, the direction of the saccade evoked from the oculomotor vermis was topographically organized.(ABSTRACT TRUNCATED AT 400 WORDS)

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Purkinje cell activity in the primate flocculus during optokinetic stimulation, smooth pursuit eye movements and VOR-suppression

Experimental Brain Research ◽

10.1007/bf00240502 ◽

1984 ◽

Vol 55 (1) ◽

Cited By ~ 37

Author(s):

U. B�ttner ◽

W. Waespe

Keyword(s):

Eye Movements ◽

Purkinje Cell ◽

Smooth Pursuit ◽

Cell Activity ◽

Optokinetic Stimulation ◽

Smooth Pursuit Eye Movements ◽

Pursuit Eye Movements

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Inverse-Dynamics Representation of Eye Movements by Cerebellar Purkinje Cell Activity during Short-Latency Ocular-Following Responses

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1996.tb15709.x ◽

1996 ◽

Vol 781 (1 Lipids and Sy) ◽

pp. 314-321 ◽

Cited By ~ 11

Author(s):

KENJI KAWANO ◽

MUNETAKA SHIDARA ◽

AYA TAKEMURA ◽

YUKA INOUE ◽

HIROAKI GOMI ◽

...

Keyword(s):

Eye Movements ◽

Purkinje Cell ◽

Inverse Dynamics ◽

Cell Activity ◽

Short Latency ◽

Cerebellar Purkinje Cell ◽

Ocular Following

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Purkinje Cell Activity During Suppression of Voluntary Eye Movements in Rhesus Macaques

10.1101/2021.03.26.437236 ◽

2021 ◽

Author(s):

Eric Avila ◽

Nico A. Flierman ◽

Peter J. Holland ◽

Pieter R. Roelfsema ◽

Maarten A. Frens ◽

...

Keyword(s):

Eye Movements ◽

Purkinje Cell ◽

Behavioral Control ◽

Rhesus Macaques ◽

Cell Activity ◽

Cerebral Control ◽

Trial History ◽

Voluntary Eye Movements ◽

External Stimuli ◽

Conscious Control

AbstractConscious control of actions helps us to reach our goals by suppressing responses to distracting external stimuli. The cerebellum has been suggested to complement cerebral control of inhibition of targeted movements (conscious control), though by what means, remains unclear. By measuring Purkinje cell (PC) responses during antisaccades, we show that the cerebellum not only plays a role in the execution of eye movements, but also in during the volitional inhibition thereof. We found that simple spike (SS) modulation during instruction and execution of prosaccades and antisaccades was prominent in PCs of both medial and lateral cerebellum, showing distinct, time-ordered sequences, but each with different sensitivities for execution and trial-history. SS activity in both regions modulated bidirectionally, with both facilitation (increasing SS firing) and suppression (decreasing SS firing) PCs showing firing-rate changes associated with instruction and execution, respectively. These findings show that different cerebellar regions can contribute to behavioral control and inhibition, but with different propensities, enriching the cerebellar machinery in executive control.

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