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.

Dynamics and Kinematics of the Angular Vestibulo-Ocular Reflex in Monkey: Effects of Canal Plugging

1998 ◽  
Vol 80 (6) ◽  
pp. 3077-3099 ◽  
Author(s):  
Sergei B. Yakushin ◽  
Theodore Raphan ◽  
Jun-Ichi Suzuki ◽  
Yasuko Arai ◽  
Bernard Cohen
Keyword(s):  
Time Constant ◽  
Three Dimensional ◽  
Low Frequency ◽  
Stimulus Velocity ◽  
Ocular Reflex ◽  
Left Posterior ◽  
Vestibulo Ocular Reflex ◽  
Afferent Response ◽  
Short Time ◽  
Eye Velocity

Yakushin, Sergei B., Theodore Raphan, Jun-Ichi Suzuki, Yasuko Arai, and Bernard Cohen. Dynamics and kinematics of the angular vestibulo-ocular reflex in monkey: effects of canal plugging. J. Neurophysiol. 80: 3077–3099, 1998. Horizontal and roll components of the angular vestibulo-ocular reflex (aVOR) were elicited by sinusoidal rotation at frequencies from 0.2 Hz (60°/s) to 4.0 Hz (≈6°/s) in cynomolgus monkeys. Animals had both lateral canals plugged (VC, vertical canals intact), both lateral canals and one pair of the vertical canals plugged (RALP, right anterior and left posterior canals intact; LARP, left anterior and right posterior canal intact), or all six semicircular canal plugged (NC, no canals). In normal animals, horizontal and roll eye velocity was in phase with head velocity and peak horizontal and roll gains were ≈0.8 and 0.6 in upright and 90° pitch, respectively. NC animals had small aVOR gains at 0.2 Hz, and the temporal phases were shifted ≈90° toward acceleration. As the frequency increased to 4 Hz, aVOR temporal gains and phases tended to normalize. Findings were similar for the LARP, RALP, and VC animals when they were rotated in the planes of the plugged canals. That is, they tended to normalize at higher frequencies. A model was developed incorporating the geometric organization of the canals and first order canal-endolymph dynamics. Canal plugging was modeled as an alteration in the low frequency 3-db roll-off and corresponding dominant time constant. The shift in the low-frequency 3-dB roll-off was seen in the temporal responses as a phase lead of the aVOR toward acceleration at higher frequencies. The phase shifted toward stimulus velocity as the frequency increased toward 4.0 Hz. By incorporating a dynamic model of the canals into the three-dimensional canal system, the spatial responses were predicted at all frequencies. Animals were also stimulated with steps of velocity in planes parallel to the plugged lateral canals. This induced a response with a short time constant and low peak velocity in each monkey. Gains were normalized for step rotation with respect to time constant as (steady state eye velocity)/(stimulus acceleration × time constant). Using this procedure, the gains were the same in canal plugged as in normal animals and corresponded to gains obtained in the frequency analysis. The study suggests that canal plugging does not block the afferent response to rotation, it merely shifts the dynamic response to higher frequencies.

scholarly journals Both ongoing alpha and visually induced gamma oscillations show reliable diversity in their across-site phase-relations

2015 ◽  
Vol 113 (5) ◽  
pp. 1556-1563 ◽  
Author(s):  
Freek van Ede ◽  
Stan van Pelt ◽  
Pascal Fries ◽  
Eric Maris
Keyword(s):  
Phase Relation ◽  
Visual Stimulation ◽  
Low Frequency ◽  
Gamma Oscillations ◽  
Phase Relations ◽  
Neural Oscillations ◽  
High Signal ◽  
Noninvasive Methods ◽  
Healthy Human ◽  
Systems Neuroscience

Neural oscillations have emerged as one of the major electrophysiological phenomena investigated in cognitive and systems neuroscience. These oscillations are typically studied with regard to their amplitude, phase, and/or phase coupling. Here we demonstrate the existence of another property that is intrinsic to neural oscillations but has hitherto remained largely unexplored in cognitive and systems neuroscience. This pertains to the notion that these oscillations show reliable diversity in their phase-relations between neighboring recording sites (phase-relation diversity). In contrast to most previous work, we demonstrate that this diversity is restricted neither to low-frequency oscillations nor to periods outside of sensory stimulation. On the basis of magnetoencephalographic (MEG) recordings in humans, we show that this diversity is prominent not only for ongoing alpha oscillations (8–12 Hz) but also for gamma oscillations (50–70 Hz) that are induced by sustained visual stimulation. We further show that this diversity provides a dimension within electrophysiological data that, provided a sufficiently high signal-to-noise ratio, does not covary with changes in amplitude. These observations place phase-relation diversity on the map as a prominent and general property of neural oscillations that, moreover, can be studied with noninvasive methods in healthy human volunteers. This opens important new avenues for investigating how neural oscillations contribute to the neural implementation of cognition and behavior.

scholarly journals Presyncodon, a Web Server for Gene Design with the Evolutionary Information of the Expression Hosts

2018 ◽  
Vol 19 (12) ◽  
pp. 3872 ◽  
Author(s):  
Jian Tian ◽  
Qingbin Li ◽  
Xiaoyu Chu ◽  
Ningfeng Wu
Keyword(s):  
High Frequency ◽  
Synonymous Codon ◽  
Low Frequency ◽  
Synonymous Codon Usage ◽  
Codon Usage Pattern ◽  
Evolutionary Information ◽  
Specific Expression ◽  
Synonymous Codons ◽  
New Genes ◽  
And Function

In the natural host, most of the synonymous codons of a gene have been evolutionarily selected and related to protein expression and function. However, for the design of a new gene, most of the existing codon optimization tools select the high-frequency-usage codons and neglect the contribution of the low-frequency-usage codons (rare codons) to the expression of the target gene in the host. In this study, we developed the method Presyncodon, available in a web version, to predict the gene code from a protein sequence, using built-in evolutionary information on a specific expression host. The synonymous codon-usage pattern of a peptide was studied from three genomic datasets (Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae). Machine-learning models were constructed to predict a selection of synonymous codons (low- or high-frequency-usage codon) in a gene. This method could be easily and efficiently used to design new genes from protein sequences for optimal expression in three expression hosts (E. coli, B. subtilis, and S. cerevisiae). Presyncodon is free to academic and noncommercial users; accessible at http://www.mobioinfor.cn/presyncodon_www/index.html.

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.

A new time coding approach for CTVEP-based brain-computer interface

2020 ◽  
Vol 20 (3) ◽  
pp. 743-757
Author(s):  
Teng Ma ◽  
Xuezhuan Zhao
Keyword(s):  
Information Transfer ◽  
High Performance ◽  
Visual Stimulation ◽  
Brain Computer Interface ◽  
Low Frequency ◽  
Computer Interface ◽  
Binary Codes ◽  
Frequency Change ◽  
Time Coding ◽  
New Time

The chromatic transient visual evoked potential (CTVEP)-based brain-computer interface (BCI) can provide safer and more comfortable stimuli than the traditional VEP-based BCIs due to its low frequency change and no luminance variation in the visual stimulation. However, it still generates relatively few codes that correspond to input commands to control the outside devices, which limits its application in the practical BCIs to some extent. Aiming to obtain more codes, we firstly proposes a new time coding technique to CTVEP-based BCI by utilizing a combination of two 4-bit binary codes to construct four 8-bit binary codes to increase the control commands to extend its application in practice. In the experiment, two time-encoded isoluminant chromatic stimuli are combined to serve as different commands for BCI control, and the results show that the high performance based on the new time coding approach with the average accuracy up to 90.28% and average information transfer rate up to 27.78 bits/min for BCI can be achieved. It turns out that the BCI system based on the proposed method is feasible, stable and efficient, which makes the method very suitable for the practical application of BCIs, such as military, entertainment and medical enterprise.

scholarly journals Free and sulfated steroids secretion in postpubertal boars (Sus scrofa domestica)

Reproduction ◽  
2014 ◽  
Vol 148 (3) ◽  
pp. 303-314 ◽  
Author(s):  
G Schuler ◽  
Y Dezhkam ◽  
L Bingsohn ◽  
B Hoffmann ◽  
K Failing ◽  
...  
Keyword(s):  
Venous Blood ◽  
Low Frequency ◽  
Peripheral Circulation ◽  
Target Cells ◽  
Sulfated Steroids ◽  
Liquid Chromatography Tandem Mass ◽  
Testicular Steroidogenesis ◽  
High Production ◽  
And Function

Sulfated steroids have been traditionally regarded as inactive metabolites. However, they may also serve as precursors for the production of active free steroids in target cells. In this study, we used the boar as a model to study the metabolism, transport, and function of steroid sulfates due to their high production in the porcine testicular–epididymal compartment, of which the role is unknown. To characterize the secretion of free and sulfated steroids, plasma samples were collected from six postpubertal boars over 6 h every 20 min from the jugular vein. Long-term secretion profiles were also established in seven boars stimulated with human chorionic gonadotropin. To directly characterize the testicular output, samples were collected from superficial testicular arterial and venous blood vessels. Testosterone, androstenedione and sulfated pregnenolone, DHEA, estrone (E1), and estradiol-17β (E2) were determined by liquid chromatography–tandem mass spectrometry. Free E1 and E2 were measured by RIA. Irrespective of a high variability between individuals, the results suggest that i) all steroids assessed are primarily produced in the testis, ii) they exhibit similar profiles pointing to a pulsatile secretion with low frequency (three to five pulses per day), and iii) after synthesis at least a major proportion is immediately released into peripheral circulation. The fact that all steroid sulfates assessed are original testicular products and their high correlations with one another suggest their role as being intermediates of testicular steroidogenesis rather than as being inactivated end products. Moreover, a substantial use of sulfated steroids in porcine testicular steroidogenesis would assign a crucial regulatory role to steroid sulfatase, which is highly expressed in Leydig cells.

Normal and Adapted Visuooculomotor Reflexes in Goldfish

1997 ◽  
Vol 77 (3) ◽  
pp. 1099-1118 ◽  
Author(s):  
Eric Marsh ◽  
Robert Baker
Keyword(s):  
Visual Stimulus ◽  
Visual Motion ◽  
Visual Stimuli ◽  
Adaptive Plasticity ◽  
Visual Training ◽  
Optokinetic Response ◽  
Stimulus Velocity ◽  
Visuomotor Behavior ◽  
Distributed Circuits ◽  
Eye Velocity

Marsh, Eric and Robert Baker. Normal and adapted visuooculomotor reflexes in goldfish. J. Neurophysiol. 77: 1099–1118. Under normal physiological conditions, whole field visual motion generally occurs in response to either active or passive self-motion. In the laboratory, selective movement of the visual surround produces an optokinetic response (OKR) that acts primarily to support the vestibuloocular reflex (VOR). During visual world motion, however, the OKR can be viewed as operating independently over frequency and amplitude ranges insufficient for vestibular activation. The goal of the present study was to characterize this isolated behavior of the OKR in goldfish as an essential step for studying central neuronal correlates of visual-vestibular interactions and the mechanisms underlying oculomotor adaptation. After presentation of either binocular sinusoidal or step visual stimuli, conjugate eye movements were elicited with an amplitude and phase profile similar to that of other vertebrates. An early and a delayed component were measured with different dynamics that could be altered independently by visual training. The ensuing visuomotor plasticity was robust and exhibited five major characteristics. First, the gain of both early and delayed components of the OKR increased >100%. Second, eye velocity decreased 0.5–2.0 s before the change in direction of stimulus velocity. Third, on lengthening the duration of a constant velocity visual stimulus (e.g., from 8 to 16 s), eye velocity decreased toward 0°/s. This behavior was correlated with the direction and period as opposed to the frequency of the visual stimulus (“period tuning”). Fourth, visual stimulus training increased VOR eye velocity with a ratio of 0.6 to 1 to that measured for the OKR. Fifth, after OKR adaptation, eye velocity consistently oscillated in a conjugate, symmetrical fashion at 2.4 Hz in the light, whereas in the dark, a rhythmical low-amplitude eye velocity occurred at the visual training frequency. We conclude that the frequency and amplitude of visual stimuli for eliciting the goldfish OKR are well suited for complementing the VOR. Unlike most mammals, OKR adaptive modifications significantly alter VOR gain, whereas the effects of VOR training are much less on OKR gain. These observations suggest that both distributed circuits and discrete neuronal populations control visuo- and vestibulomotor performance. Finally, the existence of a rhythmic, “period tuned” visuomotor behavior provides a unique opportunity to examine the neuronal mechanisms of adaptive plasticity.

scholarly journals Language prediction mechanisms in human auditory cortex

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
K. J. Forseth ◽  
G. Hickok ◽  
P. S. Rollo ◽  
N. Tandon
Keyword(s):  
Speech Perception ◽  
Auditory Cortex ◽  
Speech Production ◽  
Low Frequency ◽  
Spoken Language ◽  
Planum Temporale ◽  
Gamma Power ◽  
And Function ◽  
Predictive Mechanisms ◽  
Stimulation Of

Abstract Spoken language, both perception and production, is thought to be facilitated by an ensemble of predictive mechanisms. We obtain intracranial recordings in 37 patients using depth probes implanted along the anteroposterior extent of the supratemporal plane during rhythm listening, speech perception, and speech production. These reveal two predictive mechanisms in early auditory cortex with distinct anatomical and functional characteristics. The first, localized to bilateral Heschl’s gyri and indexed by low-frequency phase, predicts the timing of acoustic events. The second, localized to planum temporale only in language-dominant cortex and indexed by high-gamma power, shows a transient response to acoustic stimuli that is uniquely suppressed during speech production. Chronometric stimulation of Heschl’s gyrus selectively disrupts speech perception, while stimulation of planum temporale selectively disrupts speech production. This work illuminates the fundamental acoustic infrastructure—both architecture and function—for spoken language, grounding cognitive models of speech perception and production in human neurobiology.

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.

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