scholarly journals Eye Movements and Abducens Motoneuron Behavior after Cholinergic Activation of the Nucleus Reticularis Pontis Caudalis

SLEEP ◽  
2010 ◽  
Vol 33 (11) ◽  
pp. 1517-1527 ◽  
Author(s):  
Javier Márquez-Ruiz ◽  
Miguel Escudero
Keyword(s):  
Eye Movements ◽  
Nucleus Reticularis ◽  
Cholinergic Activation

Smooth-Pursuit Eye-Movement Deficits With Chemical Lesions in Macaque Nucleus Reticularis Tegmenti Pontis

1999 ◽  
Vol 82 (3) ◽  
pp. 1178-1186 ◽  
Author(s):  
David A. Suzuki ◽  
Tetsuto Yamada ◽  
Rebecca Hoedema ◽  
Robert D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Ibotenic Acid ◽  
Frontal Eye Field ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis ◽  
Dorsolateral Pontine Nucleus

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over ∼3 days when maintained pursuit gains attained normal values. The step-ramp, “Rashbass” task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a component of a cortico-ponto-cerebellar circuit that presumably involves the pursuit area of the frontal eye field (FEF) and projects to ocular motor-related areas of the cerebellum. This FEF-NRTP-cerebellum path would parallel a middle and medial superior temporal cerebral cortical area-dorsolateral pontine nucleus-cerebellum pathway also known to be involved with regulating smooth-pursuit eye movements.

Smooth pursuitlike eye movements evoked by microstimulation in macaque nucleus reticularis tegmenti pontis

1996 ◽  
Vol 76 (5) ◽  
pp. 3313-3324 ◽  
Author(s):  
T. Yamada ◽  
D. A. Suzuki ◽  
R. D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Current Intensity ◽  
Image Motion ◽  
Eye Position ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis

1. Smooth pursuitlike eye movements were evoked with low current microstimulation delivered to rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. Microstimulation sites were selected by the observation of modulations in single-cell firing rates that were correlated with periodic smoothpursuit eye movements. Current intensities ranged from 10 to 120 microA and were routinely < 40 microA. Microstimulation was delivered either in the dark with no fixation, 100 ms after a fixation target was extinguished, or during maintained fixation of a stationary or moving target. Evoked eye movements also were studied under open-loop conditions with the target image stabilized on the retina. 2. Eye movements evoked in the absence of a target rapidly accelerated to a constant velocity that was maintained for the duration of the microstimulation. Evoked eye speeds ranged from 3.7 to 23 deg/s and averaged 11 deg/s. Evoked eye speed appeared to be linearly related to initial eye position with a sensitivity to initial eye position that averaged 0.23 deg.s-1.deg-1. While some horizontal and oblique smooth eye movements were elicited, microstimulation resulted in upward eye movements in 89% of the sites. 3. Evoked eye speed was found to be dependent on microstimulation pulse frequency and current intensity. Within limits, evoked eye speed increased with increases in stimulation frequency or current intensity. For stimulation frequencies < 300–400 Hz, only smooth pursuit-like eye movements were evoked. At higher stimulation frequencies, accompanying saccades consistently were elicited. 4. Feedback of retinal image motion interacted with the evoked eye movements to decrease eye speed if the visual motion was in the opposite direction as the evoked, pursuit-like eye movements. 5. The results implicate rNRTP as part of the neuronal substrate that controls smooth-pursuit eye movements. NRTP appears to be divided functionally into a rostral, pursuit-related portion and a caudal, saccade-related area. rNRTP is a component of a corticopontocerebellar circuit that presumably involves the pursuit area of the frontal eye field and that parallels the middle and medial superior temporal cerebral cortical/dorsalateral pontine nucleus (MT/MST-DLPN-cerebellum) pathway known to be involved also with regulating smooth-pursuit eye movements.

Role of the nucleus reticularis tegmenti pontis on visually induced eye movements

1982 ◽  
Vol 78 (3) ◽  
pp. 503-516 ◽  
Author(s):  
Isao Kato ◽  
Koji Harada ◽  
Tadashi Nakamura ◽  
Yu Sato ◽  
Tadashi Kawasaki
Keyword(s):  
Eye Movements ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Nucleus Reticularis

Visual and oculomotor signals in nucleus reticularis tegmenti pontis in alert monkey

1985 ◽  
Vol 54 (5) ◽  
pp. 1326-1345 ◽  
Author(s):  
W. F. Crandall ◽  
E. L. Keller
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Stimulus ◽  
Saccadic Eye Movements ◽  
Visual Response ◽  
Optokinetic Stimulation ◽  
Visual Neurons ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Nucleus Reticularis ◽  
Movement Field

A small region in the dorsal midline portion of the nucleus reticularis tegmenti pontis (NRTP) in monkeys contains neurons that respond to focal visual stimuli or during saccadic eye movements or both. None of these cells or any others in this region respond to the motion of large visual fields (optokinetic stimulation), although such responses were specifically sought. Thus, this group of NRTP neurons forms a completely different set of cells than those previously described in more rostral but closely adjacent portions of the pontine nuclei which respond well to optokinetic stimulation. The most frequently encountered cell type in this region of NRTP (153 neurons) produced a high-frequency burst of discharges during saccadic eye movements. Neural discharge (burst intensity or duration) was not related to saccade metrics. Instead, peak burst frequency and/or the number of spikes in a unit's burst reached a maximum when the saccade moved the eyes to a circumscribed region (movement field) of the animal's visual field. There were two subtypes of these burst neurons. In one type (44%) the movement fields were smaller and entirely contained within the oculomotor range. In the other type (56%) the movement fields consisted of a whole sector (some as wide as 180 degrees) of the entire oculomotor range. All the neurons in this sample that we were able to test in total darkness continued to produce bursts of discharges of similar profile during spontaneous saccades into their movement field. All the movement fields were retinotopically organized, although a few cells (22%) showed a marked variation of burst metrics with initial eye position. Another small group of cells in NRTP (8 neurons) responded to small spots of light turned on within a circumscribed region of the visual field while the animal maintained fixation on a separate spot of light. These visual neurons produced no saccade-related discharge. A larger group of neurons (24 out of 52 tested cells) produced both a visual response and a saccadic burst. The visual field of this type of cell was always smaller and was contained within the movement field of the cell. The response of both types of NRTP visual neurons was enhanced when the visual stimulus was to be the target for a saccadic eye movement. On double-saccade trials the visual stimulus was never present in the hemifield containing the cell's visual field.(ABSTRACT TRUNCATED AT 400 WORDS)

Smooth-Pursuit Eye-Movement-Related Neuronal Activity in Macaque Nucleus Reticularis Tegmenti Pontis

2003 ◽  
Vol 89 (4) ◽  
pp. 2146-2158 ◽  
Author(s):  
David A. Suzuki ◽  
Tetsuto Yamada ◽  
Robert D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Response Amplitude ◽  
Eye Position ◽  
Smooth Pursuit Eye Movements ◽  
Average Sensitivity ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis ◽  
Eye Velocity

Neuronal responses that were observed during smooth-pursuit eye movements were recorded from cells in rostral portions of the nucleus reticularis tegmenti pontis (rNRTP). The responses were categorized as smooth-pursuit eye velocity (78%) or eye acceleration (22%). A separate population of rNRTP cells encoded static eye position. The sensitivity to pursuit eye velocity averaged 0.81 spikes/s per °/s, whereas the average sensitivity to pursuit eye acceleration was 0.20 spikes/s per °/s2. Of the eye-velocity cells with horizontal preferences for pursuit responses, 56% were optimally responsive to contraversive smooth-pursuit eye movements and 44% preferred ipsiversive pursuit. For cells with vertical pursuit preferences, 61% preferred upward pursuit and 39% preferred downward pursuit. The direction selectivity was broad with 50% of the maximal response amplitude observed for directions of smooth pursuit up to ±85° away from the optimal direction. The activities of some rNRTP cells were linearly related to eye position with an average sensitivity of 2.1 spikes/s per deg. In some cells, the magnitude of the response during smooth-pursuit eye movements was affected by the position of the eyes even though these cells did not encode eye position. On average, pursuit centered to one side of screen center elicited a response that was 73% of the response amplitude obtained with tracking centered at screen center. For pursuit centered on the opposite side, the average response was 127% of the response obtained at screen center. The results provide a neuronal rationale for the slow, pursuit-like eye movements evoked with rNRTP microstimulation and for the deficits in smooth-pursuit eye movements observed with ibotenic acid injection into rNRTP. More globally, the results support the notion of a frontal and supplementary eye field-rNRTP-cerebellum pathway involved with controlling smooth-pursuit eye movements.

The effect of clause wrap-up on eye movements during reading

2000 ◽  
Vol 53 (4) ◽  
pp. 1061-1080 ◽  
Author(s):  
Keith Rayner ◽  
Gretchen Kambe ◽  
Susan A. Duffy
Keyword(s):  
Eye Movements ◽  
Eye Movements During Reading

Editorial: Human motion perception, eye movements, and orientation in visual space

2000 ◽  
Vol 59 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Rudolf Groner ◽  
Marina T. Groner ◽  
Kazuo Koga
Keyword(s):  
Eye Movements ◽  
Motion Perception ◽  
Visual Space ◽  
Human Motion

Eye Movements of Children and Adults While Reading Television Subtitles

2007 ◽  
Vol 12 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Géry d'Ydewalle ◽  
Wim De Bruycker
Keyword(s):  
Eye Movements ◽  
Foreign Language ◽  
Age Differences ◽  
Information Sources ◽  
Native Language ◽  
Verbal Information ◽  
Single Text ◽  
Grade 5 ◽  
Reading Patterns ◽  
Attentional System

Abstract. Eye movements of children (Grade 5-6) and adults were monitored while they were watching a foreign language movie with either standard (foreign language soundtrack and native language subtitling) or reversed (foreign language subtitles and native language soundtrack) subtitling. With standard subtitling, reading behavior in the subtitle was observed, but there was a difference between one- and two-line subtitles. As two lines of text contain verbal information that cannot easily be inferred from the pictures on the screen, more regular reading occurred; a single text line is often redundant to the information in the picture, and accordingly less reading of one-line text was apparent. Reversed subtitling showed even more irregular reading patterns (e.g., more subtitles skipped, fewer fixations, longer latencies). No substantial age differences emerged, except that children took longer to shift attention to the subtitle at its onset, and showed longer fixations and shorter saccades in the text. On the whole, the results demonstrated the flexibility of the attentional system and its tuning to the several information sources available (image, soundtrack, and subtitles).

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