Effects of the APV Injection into the Abducens and the Prepositus Hypoglossi Nuclei on the Generation of Eye Position Signal

1994 ◽  
pp. 21-29 ◽  
Author(s):  
G. CHERON ◽  
P. METTENS ◽  
E. GODAUX ◽  
M. ESCUDERO
Keyword(s):  
Eye Position ◽  
Position Signal ◽  
Prepositus Hypoglossi

Discharge patterns in nucleus prepositus hypoglossi and adjacent medial vestibular nucleus during horizontal eye movement in behaving macaques

1992 ◽  
Vol 68 (1) ◽  
pp. 319-332 ◽  
Author(s):  
J. L. McFarland ◽  
A. F. Fuchs
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Vestibular Nucleus ◽  
Medial Vestibular Nucleus ◽  
Eye Position ◽  
Head Velocity ◽  
Firing Rates ◽  
Prepositus Hypoglossi ◽  
Eye Velocity

1. Monkeys were trained to perform a variety of horizontal eye tracking tasks designed to reveal possible eye movement and vestibular sensitivities of neurons in the medulla. To test eye movement sensitivity, we required stationary monkeys to track a small spot that moved horizontally. To test vestibular sensitivity, we rotated the monkeys about a vertical axis and required them to fixate a target rotating with them to suppress the vestibuloocular reflex (VOR). 2. All of the 100 units described in our study were recorded from regions of the medulla that were prominently labeled after injections of horseradish peroxidase into the abducens nucleus. These regions include the nucleus prepositus hypoglossi (NPH), the medial vestibular nucleus (MVN), and their common border (the “marginal zone”). We report here the activities of three different types of neurons recorded in these regions. 3. Two types responded only during eye movements per se. Their firing rates increased with eye position; 86% had ipsilateral “on” directions. Almost three quarters (73%) of these medullary neurons exhibited a burst-tonic discharge pattern that is qualitatively similar to that of abducens motoneurons. There were, however, quantitative differences in that these medullary burst-position neurons were less sensitive to eye position than were abducens motoneurons and often did not pause completely for saccades in the off direction. The burst of medullary burst position neurons preceded the saccade by an average of 7.6 +/- 1.7 (SD) ms and, on average, lasted the duration of the saccade. The number of spikes in the burst was well correlated with saccade size. The second type of eye movement neuron displayed either no discernible burst or an inconsistent one for on-direction saccades and will be referred to as medullary position neurons. Neither the burst-position nor the position neurons responded when the animals suppressed the VOR; hence, they displayed no vestibular sensitivity. 4. The third type of neuron was sensitive to both eye movement and vestibular stimulation. These neurons increased their firing rates during horizontal head rotation and smooth pursuit eye movements in the same direction; most (76%) preferred ipsilateral head and eye movements. Their firing rates were approximately in phase with eye velocity during sinusoidal smooth pursuit and with head velocity during VOR suppression; on average, their eye velocity sensitivity was 50% greater than their vestibular sensitivity. Sixty percent of these eye/head velocity cells were also sensitive to eye position. 5. The NPH/MVN region contains many neurons that could provide an eye position signal to abducens neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Postsaccadic eye position contributes to oculomotor error estimation in saccadic adaptation

2019 ◽  
Vol 122 (5) ◽  
pp. 1909-1917
Author(s):  
Svenja Gremmler ◽  
Markus Lappe
Keyword(s):  
Visual Feedback ◽  
Eye Position ◽  
Time Interval ◽  
Proprioceptive Information ◽  
Experimental Conditions ◽  
Position Information ◽  
Saccadic Adaptation ◽  
Position Signal ◽  
Motor Error ◽  
Saccade Control

We investigated whether the proprioceptive eye position signal after the execution of a saccadic eye movement is used to estimate the accuracy of the movement. If so, saccadic adaptation, the mechanism that maintains saccade accuracy, could use this signal in a similar way as it uses visual feedback after the saccade. To manipulate the availability of the proprioceptive eye position signal we utilized the finding that proprioceptive eye position information builds up gradually after a saccade over a time interval comparable to typical saccade latencies. We confined the retention time of gaze at the saccade landing point by asking participants to make fast return saccades to the fixation point that preempt the usability of proprioceptive eye position signals. In five experimental conditions we measured the influence of the visual and proprioceptive feedback, together and separately, on the development of adaptation. We found that the adaptation of the previously shortened saccades in the case of visual feedback being unavailable after the saccade was significantly weaker when the use of proprioceptive eye position information was impaired by fast return saccades. We conclude that adaptation can be driven by proprioceptive eye position feedback. NEW & NOTEWORTHY We show that proprioceptive eye position information is used after a saccade to estimate motor error and adapt saccade control. Previous studies on saccadic adaptation focused on visual feedback about saccade accuracy. A multimodal error signal combining visual and proprioceptive information is likely more robust. Moreover, combining proprioceptive and visual measures of saccade performance can be helpful to keep vision, proprioception, and motor control in alignment and produce a coherent representation of space.

Eye movements induced by pontine stimulation: interaction with visually triggered saccades

1987 ◽  
Vol 58 (2) ◽  
pp. 300-318 ◽  
Author(s):  
D. L. Sparks ◽  
L. E. Mays ◽  
J. D. Porter
Keyword(s):  
Visual Target ◽  
Motor Command ◽  
Feedback Signal ◽  
Eye Position ◽  
Saccadic System ◽  
Position Signal ◽  
Orbital Position ◽  
A Site ◽  
Induced Changes ◽  
Pontine Stimulation

1. Rhesus monkeys were trained to look to brief visual targets presented in an otherwise darkened room. On some trials, after the visual target was extinguished but before a saccade to it could be initiated, the eyes were driven to another orbital position by microstimulation of the paramedian pontine reticular formation. If, as current models of the saccadic system suggest, a copy of the motor command is used as a feedback signal of eye position, failure to compensate for stimulation-induced movements would indicate that stimulation occurred at a site beyond the point from which the eye position signal was derived. 2. Animals compensated for perturbations of eye position induced by stimulation of most pontine sites by making saccades that directed gaze to the position of the visual target. With stimulation at other pontine sites, compensatory saccades did not occur. 3. Pontine stimulation sometimes triggered, prematurely, impending visually directed saccades. The direction and amplitude of the premature movement depended upon the location of the briefly presented visual target. The amplitude of the premature movement was also a function of the interval between the stimulation train and the impending saccade. These data suggest that input signals for the horizontal and vertical pulse/step generators develop gradually during the presaccadic interval. Saccade trigger signals need to be delayed until the formation of these signals is completed. 4. The implications of these findings for models of the saccadic system are discussed. Robinson's local feedback model of the saccadic system can explain compensation for pontine stimulation-induced changes in eye position but cannot easily account for the failure to compensate for perturbations in eye position produced by stimulation at other sites. Modified versions of Robinson's model, which assume that the input signal to the pulse/step generator is the desired displacement of the eye, can account for both compensation and the failure to compensate since two separate neural integrators are employed. However, these models ignore kinematic arguments that commands to the extraocular muscles must specify the absolute position of the eye in the orbit rather than a relative movement from a previous position.

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.

Visual Sensitivity Shifts with Perceived Eye Position

2013 ◽  
Vol 25 (7) ◽  
pp. 1180-1189 ◽  
Author(s):  
Bartholomäus Odoj ◽  
Daniela Balslev
Keyword(s):  
Visuospatial Attention ◽  
Visual Sensitivity ◽  
Functional Coupling ◽  
Eye Position ◽  
Lateral Eye ◽  
Position Signal ◽  
Letter Array ◽  
Eye Rotation ◽  
Sound Experiment ◽  
Selection Of

Spatial attention can be defined as the selection of a location for privileged stimulus processing. Most oculomotor structures, such as the superior colliculus or the FEFs, play an additional role in visuospatial attention. Indeed, electrical stimulation of these structures can cause changes in visual sensitivity that are location specific. We have proposed that the recently discovered ocular proprioceptive area in the human postcentral gyrus (S1EYE) may have a similar function. This suggestion was based on the observation that a reduction of excitability in this area with TMS causes not only a shift in perceived eye position but also lateralized changes in visual sensitivity. Here we investigated whether these shifts in perceived gaze position and visual sensitivity are spatially congruent. After continuous theta burst stimulation over S1EYE, participants underestimated own eye rotation, so that saccades from a lateral eye rotation undershoot a central sound (Experiment 1). They discriminated letters faster if they were presented nearer the orbit midline (Experiment 2) and spent less time looking at locations nearer the orbit midline when searching for a nonexistent target in a letter array (Experiment 3). This suggests that visual sensitivity increased nearer the orbit midline, in the same direction as the shift in perceived eye position. This spatial congruence argues for a functional coupling between the cortical eye position signal in the somatosensory cortex and visuospatial attention.

scholarly journals The time course of the tonic oculomotor proprioceptive signal in area 3a of somatosensory cortex

2011 ◽  
Vol 106 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Yixing Xu ◽  
Xiaolan Wang ◽  
Christopher Peck ◽  
Michael E. Goldberg
Keyword(s):  
Somatosensory Cortex ◽  
Visual Processing ◽  
Time Course ◽  
Temporal Dynamics ◽  
Eye Position ◽  
Phasic Response ◽  
Tonic Response ◽  
Proprioceptive Signal ◽  
Position Signal ◽  
Area 3A

A proprioceptive representation of eye position exists in area 3a of primate somatosensory cortex (Wang X, Zhang M, Cohen IS, Goldberg ME. Nat Neurosci 10: 640–646, 2007). This eye position signal is consistent with a fusimotor response (Taylor A, Durbaba R, Ellaway PH, Rawlinson S. J Physiol 571: 711–723, 2006) and has two components during a visually guided saccade task: a short-latency phasic response followed by a tonic response. While the early phasic response can be excitatory or inhibitory, it does not accurately reflect the eye's orbital position. The late tonic response appears to carry the proprioceptive eye position signal, but it is not clear when this component emerges and whether the onset of this signal is reliable. To test the temporal dynamics of the tonic proprioceptive signal, we used an oculomotor smooth pursuit task in which saccadic eye movements and phasic proprioceptive responses are suppressed. Our results show that the tonic proprioceptive eye position signal consistently lags the actual eye position in the orbit by ∼60 ms under a variety of eye movement conditions. To confirm the proprioceptive nature of this signal, we also studied the responses of neurons in a vestibuloocular reflex (VOR) task in which the direction of gaze was held constant; response profiles and delay times were similar in this task, suggesting that this signal does not represent angle of gaze and does not receive visual or vestibular inputs. The length of the delay suggests that the proprioceptive eye position signal is unlikely to be used for online visual processing for action, although it could be used to calibrate an efference copy signal.

scholarly journals Efference Copy Provides the Eye Position Information Required for Visually Guided Reaching

1998 ◽  
Vol 80 (3) ◽  
pp. 1605-1608 ◽  
Author(s):  
Richard F. Lewis ◽  
Bertrand M. Gaymard ◽  
Rafael J. Tamargo
Keyword(s):  
Visual Information ◽  
Constant Error ◽  
Efference Copy ◽  
Eye Position ◽  
Sufficient Information ◽  
Visually Guided ◽  
Position Information ◽  
Visually Guided Reaching ◽  
Position Signal ◽  
The Mean

Lewis, Richard F., Bertrand M. Gaymard, and Rafael J. Tamargo. Efference copy provides the eye position information required for visually guided reaching. J. Neurophysiol. 80: 1605–1608, 1998. The contribution of extraocular muscle (EOM) proprioception to the eye position signal used to transform retinotopic visual information to a craniotopic reference frame remains uncertain. In this study we examined the effects of unilateral and bilateral proprioceptive deafferentation of the EOMs on the accuracy of reaching movements directed to visual targets. No significant changes occurred in the mean accuracy (constant error) or variance (variable error) of pointing after unilateral or bilateral deafferentation. We concluded that in normal animals efference copy provides sufficient information about orbital eye position to code space in craniotopic coordinates.

scholarly journals Eye Position Signal Modulates a Human Parietal Pointing Region during Memory-Guided Movements

2000 ◽  
Vol 20 (15) ◽  
pp. 5835-5840 ◽  
Author(s):  
Joseph F. X. DeSouza ◽  
Sean P. Dukelow ◽  
Joseph S. Gati ◽  
Ravi S. Menon ◽  
Richard A. Andersen ◽  
...  
Keyword(s):  
Eye Position ◽  
Position Signal

Discharge Dynamics of Oculomotor Neural Integrator Neurons During Conjugate and Disjunctive Saccades and Fixation

2003 ◽  
Vol 90 (2) ◽  
pp. 739-754 ◽  
Author(s):  
Pierre A. Sylvestre ◽  
Julia T. L. Choi ◽  
Kathleen E. Cullen
Keyword(s):  
Eye Movements ◽  
Vestibular Nucleus ◽  
Vestibular Nuclei ◽  
Medial Vestibular Nucleus ◽  
Eye Position ◽  
Neural Integrator ◽  
Abducens Nucleus ◽  
Nucleus Prepositus Hypoglossi ◽  
Prepositus Hypoglossi ◽  
Eye Velocity

Burst-tonic (BT) neurons in the prepositus hypoglossi and adjacent medial vestibular nuclei are important elements of the neural integrator for horizontal eye movements. While the metrics of their discharges have been studied during conjugate saccades (where the eyes rotate with similar dynamics), their role during disjunctive saccades (where the eyes rotate with markedly different dynamics to account for differences in depths between saccadic targets) remains completely unexplored. In this report, we provide the first detailed quantification of the discharge dynamics of BT neurons during conjugate saccades, disjunctive saccades, and disjunctive fixation. We show that these neurons carry both significant eye position and eye velocity-related signals during conjugate saccades as well as smaller, yet important, “slide” and eye acceleration terms. Further, we demonstrate that a majority of BT neurons, during disjunctive fixation and disjunctive saccades, preferentially encode the position and the velocity of a single eye; only few BT neurons equally encode the movements of both eyes (i.e., have conjugate sensitivities). We argue that BT neurons in the nucleus prepositus hypoglossi/medial vestibular nucleus play an important role in the generation of unequal eye movements during disjunctive saccades, and carry appropriate information to shape the saccadic discharges of the abducens nucleus neurons to which they project.

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