Electrophysiological evidence for a bisynaptic retinocerebellar pathway

Ariel, Michael; Fan, Tian Xing

doi:10.1152/jn.1993.69.4.1323

Cited by 15 publications

(4 citation statements)

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“…A time or velocity-varying effect of the vHIT in the dark, with a reduced gain at the final time stamp of 80 ms, is intriguing. This modulation appears to be consistent with a cerebellar role in the VOR which integrates visual and vestibular input (Ariel & Fan, 1993;Waespe & Cohen, 1983). The cerebellum modulates the VOR around 80 ms after the start of head thrust which matches the reduction of the VOR gain in the dark in the current study.…”

Section: Discussionsupporting

confidence: 86%

Reduced Vestibulo-Ocular Reflex During Fast Head Rotation in Complete Darkness

et al. 2023

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The human vestibulo-ocular reflex (VOR) leads to maintenance of the acuity of an image on the retina and contributes to the perception of orientation during high acceleration head movements. Our objective was to determine whether vision affects the horizontal VOR by assessing and comparing the performance at the boundaries of contribution of: (a) unrestricted visual information and (b) no visual information. Understanding how the VOR performs under both lighted and unlighted conditions is of paramount importance to avoiding falls, perhaps particularly among the elderly. We tested 23 participants ( M age = 35.3 years, standard error of mean ( SEM) = 2.0 years). The participants were tested with the video Head Impulse Test (vHIT), EyeSeeCam from Interacoustics™, which assesses whether VOR is of the expected angular velocity compared to head movement angular velocity. The vHIT tests were performed under two conditions: (a) in a well-lit room and (b) in complete darkness. The VOR was analyzed by evaluating the gain (quotient between eye and head angular velocity) at 40, 60 and 80 ms time stamps after the start of head movement. Additionally, we calculated the approximate linear gain between 0-100 ms through regression. The gain decreased significantly faster across time stamps in complete darkness ( p < .001), by 10% in darkness compared with a 2% decrease in light. In complete darkness, the VOR gain gradually declined, reaching a marked reduction at 80 ms by 10% ( p < .001), at which the head velocities were 150°/second or faster. The approximate linear gain value was not significantly different in complete darkness and in light. These findings suggest that information from the visual system can modulate the high velocity VOR. Subsequently, fast head turns might cause postural imbalance and momentary disorientation in poor light in people with reduced sensory discrimination or motor control, like the elderly.

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Section: Discussionsupporting

confidence: 86%

Reduced Vestibulo-Ocular Reflex During Fast Head Rotation in Complete Darkness

et al. 2023

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“…Animals of this size have Cb whose mean depth is approximately 800 μm, measured from the midline ventricular surface to its pia (Ariel and Fan, 1993; Brown and Ariel, 2009; Rosenberg and Ariel, 1990). The animals were housed at room temperature in an aquarium on a 16/8-h light-dark cycle, where they could swim and bask at will.…”

Section: Methodsmentioning

confidence: 99%

“…The protocols of animal care and surgical procedures were approved by the Saint Louis University Animal Care Committee. Details of the methods of optical recordings of turtle Cb are reported elsewhere (Ariel and Fan, 1993; Brown and Ariel, 2009; Rosenberg and Ariel, 1990). These techniques are now summarized briefly, indicating methods that are specific to recording from cerebellar slices.…”

Section: Methodsmentioning

confidence: 99%

Origin and timing of voltage-sensitive dye signals within layers of the turtle cerebellar cortex

Ariel

Brown

2010

Brain Research

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Optical recording techniques were applied to the turtle cerebellum to localize synchronous responses to microstimulation of its cortical layers and reveal the cerebellum's three-dimensional processing. The in vitro yet intact cerebellum was first immersed in voltage-sensitive dye and its responses while intact were compared to those measured in thick cerebellar slices. Each slice is stained throughout its depth, even though the pial half appeared darker during epi-illumination and lighter during trans-illumination. Optical responses were shown to be mediated by the voltagesensitive dye because the evoked signals had opposite polarity for 540-and 710-nm light, but no response to 850-nm light.Molecular layer stimulation of the intact cerebellum evoked slow transverse beams. Similar beams were observed in the molecular layer of thick transverse slices but not sagittal slices. With low currents, beams in transverse slices were restricted to sublayers within the molecular layer, conducting slowly away from the stimulus site. These excitatory beams were observed nearly all the way across the turtle cerebellum, distances of 4-6 mm. Microstimulation of the granule cell layer of both transverse or sagittal slices either evoked a local membrane depolarization restricted to a radial wedge, but these radial responses did not activate measurable molecular layer beams in transverse slices.White matter microstimulation in sagittal slices (near the ventricular surface of the turtle cerebellum) activated the granule cell and Purkinje cell layers, but not the molecular layer. These responses were nearly synchronous, were primarily caudal to the stimulation, and were blocked by cobalt ions. Therefore, synaptic responses in all cerebellar layers contribute to optical signals recorded in intact cerebellum in vitro (Brown and Ariel, 2009). Rapid radial signaling connects a sagittally-oriented, fast-conduction system of the deep layers with the transverse-oriented, slowconducting molecular layer, thereby permitting complex temporal processing between two tangential but orthogonal paths in the cerebellar cortex.

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“…The procedures used for recording the in vitro visual responses have been described in several publications, for which neural recordings were made in visual brainstem structures including pretectum, the nuclei of the accessory optic system, the optic tectum, the nucleus isthmi and the cerebellum (Ariel and Fan, 1993;Ariel and Johny, 2007;Fan et al, 1995;Kogo et al, 1998;Rosenberg and Ariel, 1990;Saha et al, 2010). The present study examined only the brainstem responses from the optic tectum.…”

Section: Preparation 2: Visual Recordings From the Optic Tectum (Ot)mentioning

confidence: 99%

Responses of thein vitroturtle brain to visual and auditory stimuli during severe hypoxia

Ariel¹,

Ahuja²,

Warren³

2022

Preprint

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North American pond turtles (Emydidae) are renowned for their ability to survive extreme hypoxia and anoxia, which enables several species to overwinter in ice-locked, anoxic freshwater ponds and bogs for months. Centrally important for surviving these conditions is a profound metabolic suppression, which enables ATP demands to be met entirely with glycolysis. Despite this, turtles have occasionally been observed exploring their natural and laboratory environments while anoxic and can still respond to sensory stimuli. To better understand whether anoxia limits a special sensory function, we recorded evoked potentials in a reduced brain preparation, in vitro, that was perfused with severely hypoxic artificial cerebral spinal fluid (aCSF). For recordings of visual responses, an LED light was flashed onto retinal eyecups while evoked potentials were recorded from the retina or the optic tectum. For recordings of auditory responses, a piezo motor-controlled glass actuator vibrated the tympanic membrane while evoked potentials were recorded from the cochlear nuclei. We found that visual responses decreased even with moderately hypoxic perfusate (aCSF Po2 = 30-60 torr) and completely abolished under severe hypoxia. In contrast, the evoked response within the cochlear nuclei was unattenuated with severe hypoxia (aCSF Po2 < 20 torr). These data provide further support that pond turtles have a limited ability to sense visual information in their environment even while moderately hypoxic, but that auditory input may become a principal avenue of sensory perception during extreme diving in this species.

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Electrophysiological evidence for a bisynaptic retinocerebellar pathway

Cited by 15 publications

References 0 publications

Reduced Vestibulo-Ocular Reflex During Fast Head Rotation in Complete Darkness

Reduced Vestibulo-Ocular Reflex During Fast Head Rotation in Complete Darkness

Origin and timing of voltage-sensitive dye signals within layers of the turtle cerebellar cortex

Responses of thein vitroturtle brain to visual and auditory stimuli during severe hypoxia

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