Effects of microlesions of dorsal cap of inferior olive of rabbits on optokinetic and vestibuloocular reflexes

1980 ◽  
Vol 43 (1) ◽  
pp. 182-206 ◽  
Author(s):  
N. H. Barmack ◽  
J. I. Simpson
Keyword(s):  
Eye Movements ◽  
Inferior Olive ◽  
Field Potential ◽  
Climbing Fibers ◽  
Optokinetic Stimulation ◽  
Low Velocity ◽  
Retinal Slip ◽  
Electrolytic Lesions ◽  
Contralateral Eye ◽  
Velocity Bias

1. Discrete, unilateral, electrolytic lesions of the dorsal cap of the inferior olive were made in rabbits in an attempt to assess the effect on eye movements of removal of a visual climbing fiber input to the fluocculus. The position of the lesioning electrode within the dorsal cap was adjusted on the basis of the field potential evoked by flash stimulation of the contralateral eye. 2. Electrophysiological and anatomical evidence confirmed that the microlesions of the dorsal cap destroyed 10-80% of olivary cells, but cause only slight damage to the olivocerebellar pathway originating from the contralateral dorsal cap. 3. The immediate effect of the microlesions was a spontaneous, conjugate drift of the eyes to the side contralateral to the lesion. The effects of the microlesions on eye movements were further examined using reflexes evoked by vestibular and optokinetic stimulation. 4. Postoperatively, the vestibuloocular reflex (VOR) gain was not modified, but there was a marked VOR velocity bias to the contralateral side. This velocity bias was most pronounced at low stimulus frequencies (0.02-0.05 Hz, +/- 10 degrees) and was minimal at stimulus frequencies above 0.5 Hz. 5. Monocular, sinusoidal optokinetic stimulation with a large contrast-rich visual target evokes, in normal rabbits, a conjugate asymmetric following response with a higher eye velocity for target movement from posterior to anterior. Following damage to the dorsal cap, the asymmetry of this optokinetic reflex was reversed when the target was presented to the eye contralateral to the lesion. With monocular, constant-velocity optokinetic stimulation delivered to the contralateral eye, the optokinetic gain for movement in the posterior to anterior direction was decreased. 6. These data suggest that visual climbing fibers are part of a feedback loop that reduces retinal slip of low velocity. The relatively low discharge rate of climbing fibers would seem appropriate to ecode continuously retinal slip of low velocity and to influence low-velocity eye movements.

Multiple-unit activity evoked in dorsal cap of inferior olive of the rabbit by visual stimulation

1980 ◽  
Vol 43 (1) ◽  
pp. 151-164 ◽  
Author(s):  
N. H. Barmack ◽  
D. T. Hess
Keyword(s):  
Eye Movements ◽  
Unit Activity ◽  
Inferior Olive ◽  
Visual Stimulation ◽  
Field Potential ◽  
Large Field ◽  
Sodium Pentobarbital ◽  
Optokinetic Stimulation ◽  
Multiple Unit ◽  
Contralateral Eye

1. Microelectrode recordings of multiple-unit activity were made from the dorsal cap of the inferior olive of anesthetized and unanesthetized rabbits during vestibular and optokinetic stimulation. 2. A large field potential could be evoked in the dorsal cap by photic stimulation of the contralateral eye when the rabbit was anesthetized with sodium pentobarbital or chloralose-urethan. This field potential could not be evoked in rabbits that were anesthetized with halothane or in unanesthetized rabbits. 3. Dorsal cap neurons were maximally excited by large, contrast-rich stimuli presented to the contralateral eye, moving in the posterior-anterior direction at a velocity of 1--2 degrees/s. The discharge rate of dorsal cap neurons was decreased by stimuli moving in the opposite direction. 4. The activity of dorsal cap neurons was not modulated by vestibular stimulation when visual inputs were excluded. 5. Dorsal cap neurons were sensitive to retinal slip velocity and higher derivatives of optokinetic stimulation. Their activity was related to eye movements only when the eye movements affected movement of optokinetic images on the retina.

Motor Coding in Floccular Climbing Fibers

2006 ◽  
Vol 95 (4) ◽  
pp. 2342-2351 ◽  
Author(s):  
Beerend Winkelman ◽  
Maarten Frens
Keyword(s):  
Visual Motion ◽  
Inferior Olive ◽  
Motor Behavior ◽  
Climbing Fibers ◽  
Retinal Slip ◽  
Motor Component ◽  
Prepositus Hypoglossi ◽  
Sensorimotor Information ◽  
Sensory Encoding ◽  
Oculomotor Learning

The climbing fibers (CFs) that project from the dorsal cap of the inferior olive (IO) to the flocculus of the cerebellar cortex have been reported to be purely sensory, encoding “retinal slip.” However, a clear oculomotor projection from the nucleus prepositus hypoglossi (NPH) to the IO has been shown. We therefore studied the sensorimotor information that is present in the CF signal. We presented rabbits with visual motion noise stimuli to break up the tight relation between instantaneous retinal slip and eye movement. Strikingly, the information about the motor behavior in the CF signal more than doubled that of the sensory component and was time-locked more tightly. The contribution of oculomotor signals was independently confirmed by analysis of spontaneous eye movements in the absence of visual input. The motor component of the CF code is essential to distinguish unexpected slip from self-generated slip, which is a prerequisite for proper oculomotor learning.

Eye movements evoked by microstimulation of dorsal cap of inferior olive in the rabbit

1980 ◽  
Vol 43 (1) ◽  
pp. 165-181 ◽  
Author(s):  
N. H. Barmack ◽  
D. T. Hess
Keyword(s):  
Eye Movements ◽  
Opposite Direction ◽  
Significant Interaction ◽  
Inferior Olive ◽  
Vestibular Stimulation ◽  
Low Velocity ◽  
Cerebellar Flocculus ◽  
Stimulus Train

1. Microstimulation was used in an attempt to activate selectively neurons of the dorsal cap of the inferior olive in unanesthetized rabbits, and the eye movements evoked by this microstimulation were recorded. 2. Trains of microstimulation (20--50 microA, 0.1- to 0.2-ms pulses, 10--60 pulses/s, 2--8 s duration) evoked low-velocity conjugate eye movements directed toward the side of the stimulated olive. These evoked eye movements were interrupted by resetting eye movements in the opposite direction and could be evoked only if the rabbit was in darkness. 3. The velocity of the evoked eye movements increased during a stimulus train and gradually decreased after the stimulation was terminated. 4. The low-velocity eye movements appeared to combine with eye movements evoked by vestibular stimulation without any significant interaction. 5. After transection of the olivocerebellar pathway or destruction of the contralateral cerebellar flocculus, dorsal cap microstimulation no longer evoked ipsilaterally directed eye movements.

scholarly journals Neurons in the Nucleus papilio contribute to the control of eye movements during REM sleep

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Gutierrez Herrera ◽  
F. Girard ◽  
A. Bilella ◽  
T. C. Gent ◽  
D. M. Roccaro-Waldmeyer ◽  
...  
Keyword(s):  
Eye Movements ◽  
Rem Sleep ◽  
Mammalian Brain ◽  
Eye Muscle ◽  
Genetic Ablation ◽  
Rapid Eye Movements ◽  
Motor Commands ◽  
Calbindin D28k ◽  
Contralateral Eye

AbstractRapid eye movements (REM) are characteristic of the eponymous phase of sleep, yet the underlying motor commands remain an enigma. Here, we identified a cluster of Calbindin-D28K-expressing neurons in the Nucleus papilio (NPCalb), located in the dorsal paragigantocellular nucleus, which are active during REM sleep and project to the three contralateral eye-muscle nuclei. The firing of opto-tagged NPCalb neurons is augmented prior to the onset of eye movements during REM sleep. Optogenetic activation of NPCalb neurons triggers eye movements selectively during REM sleep, while their genetic ablation or optogenetic silencing suppresses them. None of these perturbations led to a change in the duration of REM sleep episodes. Our study provides the first evidence for a brainstem premotor command contributing to the control of eye movements selectively during REM sleep in the mammalian brain.

Neurons in the cat pretectum that project to the dorsal lateral geniculate nucleus are activated during saccades

1996 ◽  
Vol 76 (5) ◽  
pp. 2907-2918 ◽  
Author(s):  
M. Schmidt
Keyword(s):  
Eye Movements ◽  
Lateral Geniculate Nucleus ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Saccadic Eye Movements ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Response Latencies ◽  
Retinal Slip ◽  
Response Properties ◽  
Dorsal Lateral Geniculate

1. Neurons in the pretectal nuclear complex that project to the ipsilateral dorsal lateral geniculate nucleus (LGNd) were identified by antidromic activation after electrical LGNd stimulation in awake cats, and their response properties were characterized to retinal image shifts elicited either by external visual stimulus movements or during spontaneous saccadic eye movements on a stationary visual stimulus, and to saccades in darkness. Eye position was monitored with the use of a scleral search coil and care was taken to assure stability of the eyes during presentation of moving visual stimuli. 2. Of a total sample of 134 cells recorded, 27 neurons were antidromically activated by electrical LGNd stimulation. In addition, responses from neurons that were not activated from the LGNd were also analyzed, including 19 “retinal slip” cells, which selectively respond to slow horizontal stimulus movements, and 21 “jerk” cells, which are specifically activated by rapid stimulus shifts. All recorded neurons were located in the nucleus of the optic tract and in the posterior pretectal nucleus. 3. In the light, neurons identified as projecting to the LGNd responded maximally to saccadic eye movements and to externally generated sudden shifts of large visual stimuli. Slow stimulus drifts did not activate these neurons. Response latencies were shorter and peak activities were increased during saccades compared with pure visual stimulation. No systematic correlation between response latency, response duration, or the number of spikes in the response and saccade direction, saccade amplitude, or saccade duration was found. Saccades and rapid stimulus shifts in the light also activated jerk cells but not retinal slip cells. 4. All 27 antidromically activated neurons also responded to spontaneous saccadic eye movements in complete darkness. Responses to saccades in the dark, however, had longer response latencies and lower peak activities than responses to saccades in light. As in the light, response parameters in darkness seemed not to code specific saccade parameters. Cells that were not activated from LGNd were found to be unresponsive to saccades in the dark. 5. According to their specific activation by saccades in darkness, LGNd-projecting pretectal neurons are termed “saccade neurons” to distinguish them from other pretectal cell populations, in particular from jerk neurons, which show similar response properties in light. 6. The saccade-related activation of pretectal saccade neurons may be used to modulate visual responses of LGNd relay cells following saccadic eye movements. Because the pretectogeniculate projection in cat most likely is GABAergic and terminates on inhibitory LGNd interneurons, its activation may lead to a saccade-locked disinhibition of relay cells. This input could counter the strong inhibition induced in the LGNd after shifts of gaze direction and lead to a resetting of LGNd cell activity.

Eye-Head Coordination during Optokinetic Stimulation in Squirrel Monkeys

1981 ◽  
Vol 90 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Takeshi Kubo ◽  
David W. Jensen ◽  
Makoto Igarashi ◽  
Jerry L. Homick
Keyword(s):  
Statistical Analysis ◽  
Eye Movements ◽  
Negative Correlation ◽  
Guinea Pigs ◽  
Significant Negative Correlation ◽  
Squirrel Monkeys ◽  
Slow Phase ◽  
Optokinetic Stimulation ◽  
The Gaze ◽  
Significant Difference

Head and eye movements in the yaw plane were recorded during and after optokinetic stimulation in squirrel monkeys. 1) Phasic or tonic head deviations to the side of the ocular quick phase occurred in 94% of total recordings (n = 50) during the perstimulus period, and in 75% of recordings (n = 49) during the poststimulus period. Magnitude of mean head deviation was significantly different between perstimulus and poststimulus periods. 2) Head nystagmus associated with eye nystagmus was consistently observed in seven of nine squirrel monkeys during optokinetic stimulation. Squirrel monkeys are thereby less prone to display head nystagmus than either guinea pigs, pigeons or chickens. 3) Slow phase speeds of coupled head and eye nystagmus were subjected to statistical analysis. A highly significant negative correlation was found between slow phase head and eye speeds. The correlation coefficient was −0.81 at 60°/sec stimulus (n = 119) and −0.72 at 100°/sec stimulus (n = 131). The gaze speed, calculated by summing the head and eye speeds, was 59.1 ± 6.8/sec at 60°/sec and 92.2 ± 11.4 at 100°/sec stimulus. There was no significant difference between the gaze speed in a free head condition and the eye speed when the head was fixed.

A Functionally Important Feature of the Distribution of the Olivo–Cerebellar Climbing Fibers

1974 ◽  
Vol 52 (6) ◽  
pp. 1212-1217 ◽  
Author(s):  
J. Courville ◽  
F. Faraco-Cantin ◽  
N. Diakiw
Keyword(s):  
Cerebellar Cortex ◽  
Central Region ◽  
Inferior Olive ◽  
Molecular Layer ◽  
Climbing Fibers ◽  
Striking Feature ◽  
Contralateral Projection

The olivo–cerebellar projection has been demonstrated by injections of small volumes of tritiated l-leucine in the inferior olive. A strictly contralateral projection to the cerebellar cortex has been found. Labelling of terminal fibers in the molecular layer is restricted to the paravermian and lateral regions of cortex after an injection of the central region of the olive. The distribution presents a very striking feature: the label is distributed along sagittal bands about 0.4 mm wide interrupted by empty spaces of the same width. It is suggested that an extra-olivary source provides the climbing fibers distributed in these spaces.

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