Characteristics of eye velocity storage during periods of suppression and reversal of eye velocity in monkeys

1986 ◽  
Vol 65 (1) ◽  
Author(s):  
W. Waespe ◽  
U. Schwarz
Keyword(s):  
Velocity Storage ◽  
Eye Velocity

Quantifying the Ontogeny of Optokinetic and Vestibuloocular Behaviors in Zebrafish, Medaka, and Goldfish

2004 ◽  
Vol 92 (6) ◽  
pp. 3546-3561 ◽  
Author(s):  
James C. Beck ◽  
Edwin Gilland ◽  
David W. Tank ◽  
Robert Baker
Keyword(s):  
Visual Stimulation ◽  
Larval Fish ◽  
Low Frequency ◽  
Velocity Storage ◽  
Active Movement ◽  
Stimulus Velocity ◽  
Oculomotor Behavior ◽  
Bode Plots ◽  
And Function ◽  
Eye Velocity

We quantitatively studied the ontogeny of oculomotor behavior in larval fish as a foundation for studies linking oculomotor structure and function with genetics. Horizontal optokinetic and vestibuloocular reflexes (OKR and VOR, respectively) were measured in three different species (goldfish, zebrafish, and medaka) during the first month after hatching. For all sizes of medaka, and most zebrafish, Bode plots of OKR (0.065–3.0 Hz, ±10°/s) revealed that eye velocity closely followed stimulus velocity (gain > 0.8) at low frequency but dropped sharply above 1 Hz (gain < 0.3 at 3 Hz). Goldfish showed increased gain proportional to size across frequencies. Linearity testing with steps and sinusoids showed excellent visual performance (gain > 0.8) in medaka almost from hatching; but zebrafish and goldfish exhibited progressive improvement, with only the largest equaling medaka performance. Monocular visual stimulation in zebrafish and goldfish produced gains of 0.5 versus <0.1 for the eye viewing a moving versus stationary stimulus pattern but 0.25 versus <0.1 in medaka. Angular VOR appeared much later than OKR, initially at only high accelerations (>200°/s at 0.5 Hz), first in medaka followed by larger (8.11 mm) zebrafish; but it was virtually nonexistent in goldfish. Velocity storage was not observed except for an eye velocity build-up in the largest medaka. In summary, a robust OKR was achieved shortly after hatching in all three species. In contrast, larval fish seem to be unique among vertebrates tested in their lack of significant angular VOR at stages where active movement is required for feeding and survival.

Spatial orientation of postrotatory nystagmus during static roll tilt in cats

2002 ◽  
Vol 12 (1) ◽  
pp. 15-23
Author(s):  
Keiko Yasuda ◽  
Hiroaki Fushiki ◽  
Rinnosuke Wada ◽  
Yukio Watanabe
Keyword(s):  
Spatial Orientation ◽  
Vertical Axis ◽  
Longitudinal Axis ◽  
Velocity Storage ◽  
Slow Phase ◽  
Storage Mechanism ◽  
Spatial Disorientation ◽  
Acceleration And Deceleration ◽  
Eye Velocity ◽  
Roll Tilt

While the stimulation of otolith inputs reduces the duration of postrotatory nystagmus (PRN), there is still room for dialogue about the effect of static tilt on the orientation of PRN. We studied one possible influence of static roll tilt on the spatial orientation of PRN in cats. The animal was rotated about an earth-vertical axis (EVA) at a constant velocity of 100 deg/s with an acceleration and deceleration of 120 deg / s 2 . Within two seconds after stopping EVA rotation, the animal was passively tilted at 45 deg/s about its longitudinal axis by as much as ± 90 deg in steps of 15 deg. Eye movements were measured with magnetic search coils. The angle of the PRN plane and its slow phase eye velocity were measured. The time constant of PRN decreased with an increase in roll tilt. The PRN plane remained earth horizontal within a range of ± 30 deg roll tilt. Beyond this range, the velocity of PRN decreased too rapidly to measure any change in orientation. Our results indicate a spatially limited and temporally short interaction of the semicircular canal and otolith signals in the velocity storage mechanism of cat PRN. Our data, along with previous studies, suggest that different species show different solutions to the problem of the imbalance and spatial disorientation during contradictory stimuli.

Eye Movements During Multi-Axis Whole-Body Rotations

2003 ◽  
Vol 89 (1) ◽  
pp. 355-366 ◽  
Author(s):  
Christopher J. Bockisch ◽  
Dominik Straumann ◽  
Thomas Haslwanter
Keyword(s):  
Eye Movements ◽  
Rotation Axis ◽  
Human Subjects ◽  
Whole Body ◽  
Velocity Storage ◽  
Head Orientation ◽  
Otolith Organs ◽  
Velocity Signal ◽  
Eye Velocity ◽  
Cue Conflict

The semi-circular canals and the otolith organs both contribute to gaze stabilization during head movement. We investigated how these sensory signals interact when they provide conflicting information about head orientation in space. Human subjects were reoriented 90° in pitch or roll during long-duration, constant-velocity rotation about the earth-vertical axis while we measured three-dimensional eye movements. After the reorientation, the otoliths correctly indicated the static orientation of the subject with respect to gravity, while the semicircular canals provided a strong signal of rotation. This rotation signal from the canals could only be consistent with a static orientation with respect to gravity if the rotation-axis indicated by the canals was exactly parallel to gravity. This was not true, so a cue-conflict existed. These conflicting stimuli elicited motion sickness and a complex tumbling sensation. Strong horizontal, vertical, and/or torsional eye movements were also induced, allowing us to study the influence of the conflict between the otoliths and the canals on all three eye-movement components. We found a shortening of the horizontal and vertical time constants of the decay of nystagmus and a trend for an increase in peak velocity following reorientation. The dumping of the velocity storage occurred regardless of whether eye velocity along that axis was compensatory to the head rotation or not. We found a trend for the axis of eye velocity to reorient to make the head-velocity signal from the canals consistent with the head-orientation signal from the otoliths, but this reorientation was small and only observed when subjects were tilted to upright. Previous models of canal-otolith interaction could not fully account for our data, particularly the decreased time constant of the decay of nystagmus. We present a model with a mechanism that reduces the velocity-storage component in the presence of a strong cue-conflict. Our study, supported by other experiments, also indicates that static otolith signals exhibit considerably smaller effects on eye movements in humans than in monkeys.

Precerebellar Hindbrain Neurons Encoding Eye Velocity During Vestibular and Optokinetic Behavior in the Goldfish

2006 ◽  
Vol 96 (3) ◽  
pp. 1370-1382 ◽  
Author(s):  
James C. Beck ◽  
Paul Rothnie ◽  
Hans Straka ◽  
Susan L. Wearne ◽  
Robert Baker
Keyword(s):  
Firing Rate ◽  
Eye Movement ◽  
Time Course ◽  
Mossy Fiber ◽  
Vestibular Stimulation ◽  
Neuronal Firing ◽  
Velocity Storage ◽  
Head Velocity ◽  
Motor Error ◽  
Eye Velocity

Elucidating the causal role of head and eye movement signaling during cerebellar-dependent oculomotor behavior and plasticity is contingent on knowledge of precerebellar structure and function. To address this question, single-unit extracellular recordings were made from hindbrain Area II neurons that provide a major mossy fiber projection to the goldfish vestibulolateral cerebellum. During spontaneous behavior, Area II neurons exhibited minimal eye position and saccadic sensitivity. Sinusoidal visual and vestibular stimulation over a broad frequency range (0.1–4.0 Hz) demonstrated that firing rate mirrored the amplitude and phase of eye or head velocity, respectively. Table frequencies >1.0 Hz resulted in decreased firing rate relative to eye velocity gain, while phase was unchanged. During visual steps, neuronal discharge paralleled eye velocity latency (∼90 ms) and matched both the build-up and the time course of the decay (∼19 s) in eye velocity storage. Latency of neuronal discharge to table steps (40 ms) was significantly longer than for eye movement (17 ms), but firing rate rose faster than eye velocity to steady-state levels. The velocity sensitivity of Area II neurons was shown to equal (±10%) the sum of eye- and head-velocity firing rates as has been observed in cerebellar Purkinje cells. These results demonstrate that Area II neuronal firing closely emulates oculomotor performance. Conjoint signaling of head and eye velocity together with the termination pattern of each Area II neuron in the vestibulolateral lobe presents a unique eye-velocity brain stem-cerebellar pathway, eliminating the conceptual requirement of motor error signaling.

Characteristics of Nystagmus Evoked by Electrical Stimulation of The Uvular/Nodular Lobules of the Cerebellum in Monkey

1992 ◽  
Vol 2 (3) ◽  
pp. 235-245
Author(s):  
S.J. Heinen ◽  
D.K. Oh ◽  
E.L. Keller
Keyword(s):  
Electrical Stimulation ◽  
Velocity Storage ◽  
Large Field ◽  
Slow Phase ◽  
Stimulus Pulse ◽  
Storage Mechanism ◽  
Velocity Storage Mechanism ◽  
Stimulus Offset ◽  
Eye Velocity ◽  
Stimulation Of

Electrical stimulation in the monkey vestibulocerebellum has previously been shown to produce ocular nystagmus, but large stimulating current values were used. Using long duration (⩽10-second) stimulus pulse trains and low current values (<50 μA), we studied the nystagmus evoked by microstimulation in the uvular/nodular regions of the cerebellum. In doing this, we found quantitative differences in the nystagmus evoked from these two regions. Stimulation of the nodulus typically produced a vigorous nystagmus with a contralateral slow phase and a prolonged afternystagmus in the same direction. In contrast, stimulation of the uvula typically produced a regular ipsilateral nystagmus pattern with a very short, if any, afternystagmus in the same direction. In addition, at some stimulation sites in the uvula we observed an adaptation in the slow phase eye velocity during the time that the stimulation remained on. This effect could result in a secondary nystagmus, with a slow phase velocity direction opposite to that first evoked by the stimulation, followed by a prolonged afternystagmus in the direction of the secondary nystagmus at stimulus offset. The nystagmus evoked by these cerebellar stimulations differs from both natural nystagmus produced by large field visual motion and from the nystagmus produced by electrical stimulation of the nucleus of the optic tract. The nystagmus produced by uvular and nodular stimulation shows a shorter latency and a more rapid slow phase eye velocity buildup. The uvula stimulations also showed a much shorter afternystagmus. Also, the same nystagmus was evoked whether the animal was in a lighted or dark surround. These characteristics and recent single-unit recording studies in the uvula seem to suggest that the uvula acts not as a direct input to the velocity storage mechanism, but instead perhaps as part of an internal regulator for balance between the bilateral vestibular nuclei which are normally part of the nystagmus response. On the other hand, the nodulus, with its prolonged afternystagmus in the same direction as the evoked nystagmus, may be involved as a part of the velocity storage mechanism.

Compensatory and Orienting Eye Movements Induced By Off-Vertical Axis Rotation (OVAR) in Monkeys

2002 ◽  
Vol 88 (5) ◽  
pp. 2445-2462 ◽  
Author(s):  
Keisuke Kushiro ◽  
Mingjia Dai ◽  
Mikhail Kunin ◽  
Sergei B. Yakushin ◽  
Bernard Cohen ◽  
...  
Keyword(s):  
Eye Movements ◽  
Vertical Axis ◽  
Velocity Storage ◽  
Eye Position ◽  
Rotational Axis ◽  
Vestibuloocular Reflex ◽  
Time Constants ◽  
Head Velocity ◽  
Axis Rotation ◽  
Eye Velocity

Nystagmus induced by off-vertical axis rotation (OVAR) about a head yaw axis is composed of a yaw bias velocity and modulations in eye position and velocity as the head changes orientation relative to gravity. The bias velocity is dependent on the tilt of the rotational axis relative to gravity and angular head velocity. For axis tilts <15°, bias velocities increased monotonically with increases in the magnitude of the projected gravity vector onto the horizontal plane of the head. For tilts of 15–90°, bias velocity was independent of tilt angle, increasing linearly as a function of head velocity with gains of 0.7–0.8, up to the saturation level of velocity storage. Asymmetries in OVAR bias velocity and asymmetries in the dominant time constant of the angular vestibuloocular reflex (aVOR) covaried and both were reduced by administration of baclofen, a GABAB agonist. Modulations in pitch and roll eye positions were in phase with nose-down and side-down head positions, respectively. Changes in roll eye position were produced mainly by slow movements, whereas vertical eye position changes were characterized by slow eye movements and saccades. Oscillations in vertical and roll eye velocities led their respective position changes by ≈90°, close to an ideal differentiation, suggesting that these modulations were due to activation of the orienting component of the linear vestibuloocular reflex (lVOR). The beating field of the horizontal nystagmus shifted the eyes 6.3°/ g toward gravity in side down position, similar to the deviations observed during static roll tilt (7.0°/ g). This demonstrates that the eyes also orient to gravity in yaw. Phases of horizontal eye velocity clustered ∼180° relative to the modulation in beating field and were not simply differentiations of changes in eye position. Contributions of orientating and compensatory components of the lVOR to the modulation of eye position and velocity were modeled using three components: a novel direct otolith-oculomotor orientation, orientation-based velocity modulation, and changes in velocity storage time constants with head position re gravity. Time constants were obtained from optokinetic after-nystagmus, a direct representation of velocity storage. When the orienting lVOR was combined with models of the compensatory lVOR and velocity estimator from sequential otolith activation to generate the bias component, the model accurately predicted eye position and velocity in three dimensions. These data support the postulates that OVAR generates compensatory eye velocity through activation of velocity storage and that oscillatory components arise predominantly through lVOR orientation mechanisms.

Discharge properties of morphologically identified vestibular neurons recorded during horizontal eye movements in the goldfish

2019 ◽  
Vol 121 (5) ◽  
pp. 1865-1878 ◽  
Author(s):  
A. M. Pastor ◽  
P. M. Calvo ◽  
R. R. de la Cruz ◽  
R. Baker ◽  
H. Straka
Keyword(s):  
Eye Movements ◽  
Velocity Storage ◽  
Slow Phase ◽  
Eye Position ◽  
Type I ◽  
Abducens Nucleus ◽  
Ancestral Condition ◽  
Vestibular Neurons ◽  
Prepositus Hypoglossi ◽  
Eye Velocity

Computational capability and connectivity are key elements for understanding how central vestibular neurons contribute to gaze-stabilizing eye movements during self-motion. In the well-characterized and segmentally distributed hindbrain oculomotor network of goldfish, we determined afferent and efferent connections along with discharge patterns of descending octaval nucleus (DO) neurons during different eye motions. Based on activity correlated with horizontal eye and head movements, DO neurons were categorized into two complementary groups that either increased discharge during both contraversive (type II) eye (e) and ipsiversive (type I) head (h) movements (eIIhI) or vice versa (eIhII). Matching time courses of slow-phase eye velocity and corresponding firing rates during prolonged visual and head rotation suggested direct causality in generating extraocular motor commands. The axons of the dominant eIIhI subgroup projected either ipsi- or contralaterally and terminated in the abducens nucleus, Area II, and Area I with additional recurrent collaterals of ipsilaterally projecting neurons within the parent nucleus. Distinct feedforward commissural pathways between bilateral DO neurons likely contribute to the generation of eye velocity signals in eIhII cells. The shared contribution of DO and Area II neurons to eye velocity storage likely represents an ancestral condition in goldfish that is clearly at variance with the task separation between mammalian medial vestibular and prepositus hypoglossi neurons. This difference in signal processing between fish and mammals might correlate with a larger repertoire of visuo-vestibular-driven eye movements in the latter species that potentially required a shift in sensitivity and connectivity within the hindbrain-cerebello-oculomotor network. NEW & NOTEWORTHY We describe the structure and function of neurons within the goldfish descending octaval nucleus. Our findings indicate that eye and head velocity signals are processed by vestibular and Area II velocity storage integrator circuitries whereas the velocity-to-position Area I neural integrator generates eye position solely. This ancestral condition differs from that of mammals, in which vestibular neurons generally lack eye position signals that are processed and stored within the nucleus prepositus hypoglossi.

Model-based study of the human cupular time constant

1999 ◽  
Vol 9 (4) ◽  
pp. 293-301 ◽  
Author(s):  
Mingjia Dai ◽  
Avniel Klein ◽  
Bernard Cohen ◽  
Theodore Raphan
Keyword(s):  
Time Constant ◽  
Human Subjects ◽  
Vestibular Nerve ◽  
Velocity Storage ◽  
Slow Phase ◽  
Initial Portion ◽  
Time Constants ◽  
Model Based ◽  
Double Exponential ◽  
Eye Velocity

The time constant of the angular vestibulo-ocular reflex (aVOR), measured from the response to steps of rotation about a yaw axis, has frequently been estimated as a single exponential. However, the slow phase velocity envelope during per- or post-rotatory nystagmus is more accurately represented by two exponential modes. One represents activity in the vestibular nerve induced by deflection of the cupula, the other by activation that the input from the canals produces in the central velocity storage integrator. The sum of the cupula and the integrator responses describes the overall response of slow phase eye velocity and can be approximated by a double exponential. Frequently, there is a plateau in the initial portion of eye velocity response, but this may be masked by habituation, making the cupula contribution unobservable and impossible to estimate. Using a model-based technique to analyze responses with a clear plateau, we estimated peripheral and central vestibular time constants by double exponential fits to slow phase eye velocity. Cupular time constants were varied from 1 to 10 s to identify values that gave optimal fits of the data according to a Chi-square criterion. The mean cupular time constant for 10 human subjects was 4.2 ± 0.6 s. Fits of the data were also good for time constants between 3.5 to 7 s, but not for 1 to 3 or 7.5 to 10 s. The estimated cupular time constants also fit responses where there was no plateau. In 8 monkeys, cupular time constants were estimated as 3.9 ± 0.5 s, which agreed with those derived from activity in the vestibular nerve. There was no difference between monkey and human cupular time constants from these estimates. It is likely that the human cupular time constant is similar to that of the monkey and shorter than previously thought.

Spatial Orientation of Caloric Nystagmus in Semicircular Canal-Plugged Monkeys

2002 ◽  
Vol 88 (2) ◽  
pp. 914-928 ◽  
Author(s):  
Yasuko Arai ◽  
Sergei B. Yakushin ◽  
Bernard Cohen ◽  
Jun-Ichi Suzuki ◽  
Theodore Raphan
Keyword(s):  
Phase Velocity ◽  
Spatial Orientation ◽  
Velocity Vector ◽  
Semicircular Canals ◽  
Velocity Storage ◽  
Slow Phase ◽  
Coordinate Frame ◽  
Slow Phase Velocity ◽  
Caloric Nystagmus ◽  
Eye Velocity

We studied caloric nystagmus before and after plugging all six semicircular canals to determine whether velocity storage contributed to the spatial orientation of caloric nystagmus. Monkeys were stimulated unilaterally with cold (≈20°C) water while upright, supine, prone, right-side down, and left-side down. The decline in the slow phase velocity vector was determined over the last 37% of the nystagmus, at a time when the response was largely due to activation of velocity storage. Before plugging, yaw components varied with the convective flow of endolymph in the lateral canals in all head orientations. Plugging blocked endolymph flow, eliminating convection currents. Despite this, caloric nystagmus was readily elicited, but the horizontal component was always toward the stimulated (ipsilateral) side, regardless of head position relative to gravity. When upright, the slow phase velocity vector was close to the yaw and spatial vertical axes. Roll components became stronger in supine and prone positions, and vertical components were enhanced in side down positions. In each case, this brought the velocity vectors toward alignment with the spatial vertical. Consistent with principles governing the orientation of velocity storage, when the yaw component of the velocity vector was positive, the cross-coupled pitch or roll components brought the vector upward in space. Conversely, when yaw eye velocity vector was downward in the head coordinate frame, i.e., negative, pitch and roll were downward in space. The data could not be modeled simply by a reduction in activity in the ipsilateral vestibular nerve, which would direct the velocity vector along the roll direction. Since there is no cross coupling from roll to yaw, velocity storage alone could not rotate the vector to fit the data. We postulated, therefore, that cooling had caused contraction of the endolymph in the plugged canals. This contraction would deflect the cupula toward the plug, simulating ampullofugal flow of endolymph. Inhibition and excitation induced by such cupula deflection fit the data well in the upright position but not in lateral or prone/supine conditions. Data fits in these positions required the addition of a spatially orientated, velocity storage component. We conclude, therefore, that three factors produce cold caloric nystagmus after canal plugging: inhibition of activity in ampullary nerves, contraction of endolymph in the stimulated canals, and orientation of eye velocity to gravity through velocity storage. Although the response to convection currents dominates the normal response to caloric stimulation, velocity storage probably also contributes to the orientation of eye velocity.

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