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Sugimura T, Saito Y. Distinct proportions of cholinergic neurons in the rat prepositus hypoglossi nucleus according to their cerebellar projection targets. J Comp Neurol 2021; 529:1541-1552. [PMID: 32949021 DOI: 10.1002/cne.25035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 11/07/2022]
Abstract
Cerebellar functions are modulated by cholinergic inputs, the density of which varies among cerebellar regions. Although the prepositus hypoglossi nucleus (PHN), a brainstem structure involved in controlling gaze holding, is known as one of the major sources of these cholinergic inputs, the proportions of cholinergic neurons in PHN projections to distinct cerebellar regions have not been quantitatively analyzed. In this study, we identified PHN neurons projecting to the cerebellum by applying retrograde labeling with dextran-conjugated Alexa 488 in choline acetyltransferase (ChAT)-tdTomato transgenic rats and compared the proportion of cholinergic PHN neurons in the PHN projections to four different regions of the cerebellum, namely the flocculus (FL), the uvula and nodulus (UN), lobules III-V in the vermis (VM), and the hemispheric paramedian lobule and crus 2 (PC). In the PHN, the percentage of cholinergic PHN neurons was lower in the projection to the FL than in the projection to the UN, VM or PC. Preposito-cerebellar neurons, except for preposito-FL neurons, included different proportions of cholinergic neurons at different rostrocaudal positions in the PHN. These results suggest that cholinergic PHN neurons project to not only the vestibulocerebellum but also the anterior vermis and posterior hemisphere and that the proportion of cholinergic neurons among projection neurons from the PHN differs depending on cerebellar target areas and the rostro-caudal regions of the PHN. This study provides insights regarding the involvement of cerebellar cholinergic networks in gaze holding.
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Affiliation(s)
- Taketoshi Sugimura
- Department of Neurophysiology, Nara Medical University, Kashihara, Nara, Japan
| | - Yasuhiko Saito
- Department of Neurophysiology, Nara Medical University, Kashihara, Nara, Japan
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Lin TF, Mohammadi M, Fathalla AM, Pul D, Lüthi D, Romano F, Straumann D, Cullen KE, Chacron MJ, Huang MYY. Negative optokinetic afternystagmus in larval zebrafish demonstrates set-point adaptation. Sci Rep 2019; 9:19039. [PMID: 31836778 PMCID: PMC6910917 DOI: 10.1038/s41598-019-55457-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 11/27/2019] [Indexed: 01/05/2023] Open
Abstract
Motor learning is essential to maintain accurate behavioral responses. We used a larval zebrafish model to study ocular motor learning behaviors. During a sustained period of optokinetic stimulation in 5-day-old wild-type zebrafish larvae the slow-phase eye velocity decreased over time. Then interestingly, a long-lasting and robust negative optokinetic afternystagmus (OKAN) was evoked upon light extinction. The slow-phase velocity, the quick-phase frequency, and the decay time constant of the negative OKAN were dependent on the stimulus duration and the adaptation to the preceding optokinetic stimulation. Based on these results, we propose a sensory adaptation process during continued optokinetic stimulation, which, when the stimulus is removed, leads to a negative OKAN as the result of a changed retinal slip velocity set point, and thus, a sensorimotor memory. The pronounced negative OKAN in larval zebrafish not only provides a practical solution to the hitherto unsolved problems of observing negative OKAN, but also, and most importantly, can be readily applied as a powerful model for studying sensorimotor learning and memory in vertebrates.
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Affiliation(s)
- Ting-Feng Lin
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Mohammad Mohammadi
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Ahmed M Fathalla
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Duygu Pul
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Dennis Lüthi
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Fausto Romano
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Dominik Straumann
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Kathleen E Cullen
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland, USA.,Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Maurice J Chacron
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Melody Ying-Yu Huang
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. .,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland.
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3
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Abstract
Optokinetic eye movements are crucial for keeping a stable image on the retina during movements of the head. These eye movements can be differentiated into a cortically generated response (optokinetic look nystagmus) and the highly reflexive optokinetic stare nystagmus, which is controlled by circuits in the brainstem and cerebellum. The contributions of these infratentorial networks and their functional connectivity with the cortical eye fields are still poorly understood in humans. To map ocular motor centres in the cerebellum and brainstem, we studied stare nystagmus using small-field optokinetic stimuli in the horizontal and vertical directions in 22 healthy subjects. We were able to differentiate ocular motor areas of the pontine brainstem and midbrain in vivo for the first time. Direction and velocity-dependent activations were found in the pontine brainstem (nucleus reticularis, tegmenti pontis, and paramedian pontine reticular formation), the uvula, flocculus, and cerebellar tonsils. The ocular motor vermis, on the other hand, responded to constant and accelerating velocity stimulation. Moreover, deactivation patterns depict a governing role for the cerebellar tonsils in ocular motor control. Functional connectivity results of these hubs reveal the close integration of cortico-cerebellar ocular motor and vestibular networks in humans. Adding to the cortical concept of a right-hemispheric predominance for visual-spatial processing, we found a complementary left-sided cerebellar dominance for our ocular motor task. A deeper understanding of the role of the cerebellum and especially the cerebellar tonsils for eye movement control in a clinical context seems vitally important and is now feasible with functional neuroimaging.
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Zhang Y, Kaneko R, Yanagawa Y, Saito Y. The vestibulo- and preposito-cerebellar cholinergic neurons of a ChAT-tdTomato transgenic rat exhibit heterogeneous firing properties and the expression of various neurotransmitter receptors. Eur J Neurosci 2014; 39:1294-313. [PMID: 24593297 DOI: 10.1111/ejn.12509] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 12/11/2013] [Accepted: 01/10/2014] [Indexed: 02/02/2023]
Abstract
Cerebellar function is regulated by cholinergic mossy fiber inputs that are primarily derived from the medial vestibular nucleus (MVN) and prepositus hypoglossi nucleus (PHN). In contrast to the growing evidence surrounding cholinergic transmission and its functional significance in the cerebellum, the intrinsic and synaptic properties of cholinergic projection neurons (ChPNs) have not been clarified. In this study, we generated choline acetyltransferase (ChAT)-tdTomato transgenic rats, which specifically express the fluorescent protein tdTomato in cholinergic neurons, and used them to investigate the response properties of ChPNs identified via retrograde labeling using whole-cell recordings in brainstem slices. In response to current pulses, ChPNs exhibited two afterhyperpolarisation (AHP) profiles and three firing patterns; the predominant AHP and firing properties differed between the MVN and PHN. Morphologically, the ChPNs were separated into two types based on their soma size and dendritic extensions. Analyses of the firing responses to time-varying sinusoidal current stimuli revealed that ChPNs exhibited different firing modes depending on the input frequencies. The maximum frequencies in which each firing mode was observed were different between the neurons that exhibited distinct firing patterns. Analyses of the current responses to the application of neurotransmitter receptor agonists revealed that the ChPNs expressed (i) AMPA- and NMDA-type glutamate receptors, (ii) GABAA and glycine receptors, and (iii) muscarinic and nicotinic acetylcholine receptors. The current responses mediated by these receptors of MVN ChPNs were not different from those of PHN ChPNs. These findings suggest that ChPNs receive various synaptic inputs and encode those inputs appropriately across different frequencies.
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Affiliation(s)
- Yue Zhang
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
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Chen CC, Bockisch CJ, Bertolini G, Olasagasti I, Neuhauss SCF, Weber KP, Straumann D, Ying-Yu Huang M. Velocity storage mechanism in zebrafish larvae. J Physiol 2013; 592:203-14. [PMID: 24218543 DOI: 10.1113/jphysiol.2013.258640] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The optokinetic reflex (OKR) and the angular vestibulo-ocular reflex (aVOR) complement each other to stabilize images on the retina despite self- or world motion, a joint mechanism that is critical for effective vision. It is currently hypothesized that signals from both systems integrate, in a mathematical sense, in a network of neurons operating as a velocity storage mechanism (VSM). When exposed to a rotating visual surround, subjects display the OKR, slow following eye movements frequently interrupted by fast resetting eye movements. Subsequent to light-off during optokinetic stimulation, eye movements do not stop abruptly, but decay slowly, a phenomenon referred to as the optokinetic after-response (OKAR). The OKAR is most likely generated by the VSM. In this study, we observed the OKAR in developing larval zebrafish before the horizontal aVOR emerged. Our results suggest that the VSM develops prior to and without the need for a functional aVOR. It may be critical to ocular motor control in early development as it increases the efficiency of the OKR.
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Affiliation(s)
- Chien-Cheng Chen
- M. Ying-Yu Huang or D. Straumann: Neurology Department, University Hospital Zurich, Frauenklinikstrasse 26, CH-8091 Zurich, Switzerland. or
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De Zeeuw CI, Koekkoek SKE, van Alphen AM, Luo C, Hoebeek F, van der Steen J, Frens MA, Sun J, Goossens HHLM, Jaarsma D, Coesmans MPH, Schmolesky MT, De Jeu MTG, Galjart N. Gain and Phase Control of Compensatory Eye Movements by the Flocculus of the Vestibulocerebellum. THE VESTIBULAR SYSTEM 2004. [DOI: 10.1007/0-387-21567-0_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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van der Steen J, Tan HS. Cholinergic control in the floccular cerebellum of the rabbit. PROGRESS IN BRAIN RESEARCH 1997; 114:335-45. [PMID: 9193153 DOI: 10.1016/s0079-6123(08)63373-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- J van der Steen
- Department of Physiology, Faculty of Medicine, Erasmus University Rotterdam, The Netherlands
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Jardon B, Bonaventure N. Different effects of dopamine and piribedil (a dopamine D2 agonist) on frog monocular optokinetic nystagmus asymmetry. Vision Res 1995; 35:2665-73. [PMID: 7483308 DOI: 10.1016/0042-6989(95)00022-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Frog monocular optokinetic nystagmus (OKN) displays a directional asymmetry, reacting only to stimulations in the temporal-nasal (T-N) direction. The nasal-temporal (N-T) component is almost absent. The systemic or intrapretectal injection of Piribedil, a D2 dopamine agonist, provokes the appearance of a N-T component suppressing the monocular OKN asymmetry. Conversely, dopamine or haloperidol (a dopamine antagonist, acting mainly on D2 receptors) have no effect upon the monocular OKN unidirectionality. The monocular OKN N-T component still appears after administration of Piribedil even if this injection is preceded by administration of haloperidol which blocks the dopaminergic D2 receptors. Moreover administration of atropine (a cholinergic muscarinic antagonist) following that of Piribedil suppresses the N-T component; when injected before Piribedil, atropine prevents the appearance of the N-T component. These results suggest that in our experiments, Piribedil binds with muscarinic receptors.
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Affiliation(s)
- B Jardon
- Laboratoire de Neurophysiologie et Biologie des Comportements, UPR 419 du CNRS, Strasbourg, France
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Barton JJ, Huaman AG, Sharpe JA. Muscarinic antagonists in the treatment of acquired pendular and downbeat nystagmus: a double-blind, randomized trial of three intravenous drugs. Ann Neurol 1994; 35:319-25. [PMID: 8122884 DOI: 10.1002/ana.410350312] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We performed a double-blind, randomized trial of intravenous scopolamine, benztropine, and glycopyrrolate in 7 patients with acquired nystagmus and oscillopsia. Five patients had pendular nystagmus and 2, downbeat nystagmus. We recorded eye movements with a magnetic search coil technique and tested visual acuity and motion perception before and after administration of each drug. Scopolamine reduced nystagmus in all patients. Benztropine was moderately effective and glycopyrrolate had a negligible impact. Visual acuity improved only with scopolamine; motion discrimination and oscillopsia improved significantly with scopolamine and benztropine. Pendular and downbeat nystagmus respond to intravenous antagonists of central muscarinic receptors.
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Affiliation(s)
- J J Barton
- Division of Neurology, Toronto Hospital Neurological Center, Ontario, Canada
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Tan HS, Collewijn H, Van der Steen J. Unilateral cholinergic stimulation of the rabbit's cerebellar flocculus: asymmetric effects on optokinetic responses. Exp Brain Res 1993; 92:375-84. [PMID: 8454003 DOI: 10.1007/bf00229025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In previous work, we have demonstrated an acceleration of the buildup of slow-phase velocity of optokinetic nystagmus (OKN) after bilateral floccular injection of the aselective cholinergic agonist carbachol (Tan and Collewijn 1991; Tan et al. 1992a). In the present study we investigated the effects of unilateral floccular injections of carbachol. Such unilateral injections specifically enhanced the buildup of OKN slow-phase velocity in the direction toward the injected flocculus (ipsiversive). During binocular optokinetic stimulation, this enhancement was expressed in the motion of both eyes. Acceleration of the eye contralateral to the injected flocculus increased from 1 to about 2 degrees/s2, while the acceleration of the ipsilateral eye increased from 1 to about 1.5 degrees/s2. In contrast, buildup of contraversive OKN was unchanged. No changes were found in the steady-state OKN and optokinetic afternystagmus (OKAN). Monocular optokinetic stimulation was only effective in the nasal direction, and the effects of unilateral injection of carbachol were disconjugate. Ipsiversive OKN was enhanced only in the contralateral, seeing eye, while the response of the ipsilateral, covered eye was unchanged. We hypothesize that the directionally specific effect of unilateral cholinergic floccular stimulation on OKN is due to enhancement of predominantly the excitatory phase of modulation of the Purkinje cell's simple-spike activity by carbachol, without a marked effect of carbachol on the inhibitory phase of simple-spike modulation.
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Affiliation(s)
- H S Tan
- Department of Physiology I, Faculty of Medicine, Erasmus University Rotterdam, The Netherlands
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