Eye field in the cerebellar flocculus of pigmented rabbits determined with local electrical stimulation

Nagao, S; Ito, Masao; Karachot, Laddawan

doi:10.1016/0168-0102(85)90037-9

Cited by 52 publications

(22 citation statements)

References 21 publications

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“…Nagao et al (1985) mapped the H-zone, two V-zones, and the R-zone from which local electrical stimulation induced horizontal, vertical, and rotatory eye movements, respectively. Neurons inhibited by the H-zone, V-zones, and R-zone seem to relay signals to the horizontal recti, the vertical recti, and the obliques, respectively.…”

Section: Simulation Of Simultaneous Adaptation Of Vor and Okrmentioning

confidence: 99%

Adaptive feedback control models of the vestibulocerebellum and spinocerebellum

1992

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We extend the cerebellar learning model proposed by Kawato and Gomi (1992) to the case where a specific region of the cerebellum executes adaptive feedback control as well as feedforward control. The model is still based on the feedback-error-learning scheme. The proposed adaptive feedback control model is developed in detail as a specific neural circuit model for three different regions of the cerebellum and the learning of the corresponding representative movements: (i) the flocculus and adaptive modification of the vestibulo-ocular reflex and optokinetic eye-movement responses, (ii) the vermis and adaptive posture control, and (iii) the intermediate zones of the hemisphere and adaptive control of locomotion. As a representative example, simultaneous adaptation of the vestibulo-ocular reflex and the optokinetic eye-movement response was successfully simulated while the Purkinje cells receive copies of motor commands through recurrent neural connections as well as vestibular and retinal-slip parallel-fiber inputs.

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Section: Simulation Of Simultaneous Adaptation Of Vor and Okrmentioning

confidence: 99%

Adaptive feedback control models of the vestibulocerebellum and spinocerebellum

1992

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“…We used rabbits because their flocculus has discernible regular folial divisions (8,9), which is not the case in rats or mice.…”

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confidence: 99%

“…Several microzones have been analyzed with regard to their circuit mechanisms and specific reflex functions (not only somatic; some are autonomic) (6,7), but the actual roles of beaded fibers remain largely unknown. In this study, we focused on a particular microzone located in the flocculus [folium-p (fp)] (8,9), which receives beaded fibers containing orexins (hypocretins) (10). Orexins consist of A and B isopeptides containing 33 and 28 amino acids, respectively, and have been implicated in sleep and feeding (11)(12)(13).…”

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confidence: 99%

Orexin-neuromodulated cerebellar circuit controls redistribution of arterial blood flows for defense behavior in rabbits

Nisimaru

Mittal

Shirai

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

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We investigated a unique microzone of the cerebellum located in folium-p (fp) of rabbit flocculus. In fp, Purkinje cells were potently excited by stimulation of the hypothalamus or mesencephalic periaqueductal gray, which induced defense reactions. Using multiple neuroscience techniques, we determined that this excitation was mediated via beaded axons of orexinergic hypothalamic neurons passing collaterals through the mesencephalic periaqueductal gray. Axonal tracing studies using DiI and biotinylated dextran amine evidenced the projection of fp Purkinje cells to the ventrolateral corner of the ipsilateral parabrachial nucleus (PBN). Because, in defense reactions, arterial blood flow has been known to redistribute from visceral organs to active muscles, we hypothesized that, via PBN, fp adaptively controls arterial blood flow redistribution under orexin-mediated neuromodulation that could occur in defense behavior. This hypothesis was supported by our finding that climbing fiber signals to fp Purkinje cells were elicited by stimulation of the aortic nerve, a high arterial blood pressure, or a high potassium concentration in muscles, all implying errors in the control of arterial blood flow. We further examined the arterial blood flow redistribution elicited by electric foot shock stimuli in awake, behaving rabbits. We found that systemic administration of an orexin antagonist attenuated the redistribution and that lesioning of fp caused an imbalance in the redistribution between active muscles and visceral organs. Lesioning of fp also diminished foot shock-induced increases in the mean arterial blood pressure. These results collectively support the hypothesis that the fp microcomplex adaptively controls defense reactions under orexin-mediated neuromodulation.somatosympathetic | vestibulosympathetic | OX-1R antagonist | bicuculline | baroreceptor

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“…Reduced flocculus output would ultimately activate the superior and medial recti. (Conversely, stimulation of the flocculus outflow tracts causes eye depression and abduction [35,48]. ) The unilateral muscimol injection did not replicate the horizontal eye movement peculiarities of tottering described above, including its temporally deviated eye positions relative to controls when pitched nose-down, or its relatively nasal positions when rolled contralateral ear down.…”

Section: Resultsmentioning

confidence: 99%

The ataxic mouse as a model for studying downbeat nystagmus

Stahl

Thumser

Oommen

2012

VES

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Downbeat nystagmus (DBN) is a common eye movement complication of cerebellar disease. Use of mice to study pathophysiology of vestibulocerebellar disease is increasing, but it is unclear if mice can be used to study DBN; it has not been reported in this species. We determined whether DBN occurs in the ataxic mutant tottering, which carries a mutation in the Cacna1a gene for P/Q calcium channels. Spontaneous DBN occurred only rarely, and its magnitude did not exhibit the relationship to head tilt seen in human patients. DBN during yaw rotation was more common and shares some properties with the tilt-independent, gaze-independent component of human DBN, but differs in its dependence on vision. Hyperactivity of otolith circuits responding to pitch tilts is hypothesized to contribute to the gaze-independent component of human DBN. Mutants exhibited hyperactivity of the tilt maculo-ocular reflex (tiltMOR) in pitch. The hyperactivity may serve as a surrogate for DBN in mouse studies. TiltMOR hyperactivity correlates with hyperdeviation of the eyes and upward deviation of the head during ambulation; these may be alternative surrogates. Muscimol inactivation of the cerebellar flocculus suggests a floccular role in the tiltMOR hyperactivity and provides insight into the rarity of frank DBN in ataxic mice.

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Eye field in the cerebellar flocculus of pigmented rabbits determined with local electrical stimulation

Cited by 52 publications

References 21 publications

Adaptive feedback control models of the vestibulocerebellum and spinocerebellum

Adaptive feedback control models of the vestibulocerebellum and spinocerebellum

Orexin-neuromodulated cerebellar circuit controls redistribution of arterial blood flows for defense behavior in rabbits

The ataxic mouse as a model for studying downbeat nystagmus

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