Role of Primate Cerebellar Hemisphere in Voluntary Eye Movement Control Revealed by Lesion Effects

Abstract

. The anatomical connection between the frontal eye field and the cerebellar hemispheric lobule VII (H-VII) suggests a potential role of the hemisphere in voluntary eye movement control. To reveal the involvement of the hemisphere in smooth pursuit and saccade control, we made a unilateral lesion around H-VII and examined its effects in three Macaca fuscata that were trained to pursue visually a small target. To the step (3°)-ramp (5-20°/s) target motion, the monkeys usually showed an initial pursuit eye movement at a latency of 80 -140 ms and a small catch-up saccade at 140 -220 ms that was followed by a postsaccadic pursuit eye movement that roughly matched the ramp target velocity. After unilateral cerebellar hemispheric lesioning, the initial pursuit eye movements were impaired, and the velocities of the postsaccadic pursuit eye movements decreased. The onsets of 5°visually guided saccades to the stationary target were delayed, and their amplitudes showed a tendency of increased trial-to-trial variability but never became hypo-or hypermetric. Similar tendencies were observed in the onsets and amplitudes of catch-up saccades. The adaptation of open-loop smooth pursuit velocity, tested by a step increase in target velocity for a brief period, was impaired. These lesion effects were recognized in all directions, particularly in the ipsiversive direction. A recovery was observed at 4 wk postlesion for some of these lesion effects. These results suggest that the cerebellar hemispheric region around lobule VII is involved in the control of smooth pursuit and saccadic eye movements.

Characterization of the of the Pathological and Biochemical Markers That Correlate to the Clinical Features of Autism. Subproject 2. Contribution of Significant Delay of Neuronal Development and Metabolic Shift of Neurons to Clinical Phenotype of Autism

“…Therefore, some focal cerebellar lesions do not cause eye movement alterations that strictly correspond to the defect (Kheradmand and Zee, 2011). An example of this compensatory effect is the response to flocculus-paraflocculus lesions by a significant correction of smooth pursuit deficits by PCs in the dorsal vermis and cerebellar hemispheres (Ohki et al, 2009;Xiong et al, 2010). …”

A bi-hemispheric neuronal network model of the cerebellum with spontaneous climbing fiber firing produces asymmetrical motor learning during robot control

“…These loci constitute partially independent mechanisms for adaptive control of vertical VOR gain, whereas the bilateral pool of motor neurons innervating the muscles of the eye has been proposed to be the locus of dis-conjugate adaptation in saccades (Kapoula et al, 1996). A different hypothesis proposes that the asymmetrical mechanisms are closely related to the bi-hemispheric structure of the cerebellum (Choi et al, 2008; Ohki et al, 2009; Panouilleres et al, 2012). Lesions to the left cerebellar hemisphere lobule H-VII of the monkey significantly impair motor performance in the ipsiversive direction but also to a less degree in the contraversive direction during smooth pursuit (Ohki et al, 2009).…”

“…A different hypothesis proposes that the asymmetrical mechanisms are closely related to the bi-hemispheric structure of the cerebellum (Choi et al, 2008; Ohki et al, 2009; Panouilleres et al, 2012). Lesions to the left cerebellar hemisphere lobule H-VII of the monkey significantly impair motor performance in the ipsiversive direction but also to a less degree in the contraversive direction during smooth pursuit (Ohki et al, 2009). In a similar way, the adaptation of postsaccadic smooth pursuit velocity affects the ipsiversive direction (Ohki et al, 2009).…”

“…Lesions to the left cerebellar hemisphere lobule H-VII of the monkey significantly impair motor performance in the ipsiversive direction but also to a less degree in the contraversive direction during smooth pursuit (Ohki et al, 2009). In a similar way, the adaptation of postsaccadic smooth pursuit velocity affects the ipsiversive direction (Ohki et al, 2009). Ipsilesional saccadic adaptation was significantly reduced following unilateral cerebellar hemisphere infarctions in humans (Choi et al, 2008).…”

Features of Eye Movement Disorders in Patients With Cerebellar Lesions of Different Localization

“…Оку-ломоторные представлены дорсальным vermis-declive, folium, tuber -а также lobuli semilunares superior et inferior и внутримозжечковым ядром nucleusfastigii, и преимущественно вовлечены в управле-ние саккадической системой, но также принимают участие в прослеживающих и вергентных движениях глаз. Так, на при-матах было показано, что области, окру-жающие lobuli semilu nares superior et inferior, контролируют плавное прослежи-вание и саккады [7].…”