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Birinyi A, Rácz N, Kecskes S, Matesz C, Kovalecz G. Neural circuits underlying jaw movements for the prey-catching behavior in frog: distribution of vestibular afferent terminals on motoneurons supplying the jaw. Brain Struct Funct 2017; 223:1683-1696. [PMID: 29189907 DOI: 10.1007/s00429-017-1581-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 11/25/2017] [Indexed: 10/18/2022]
Abstract
Coordinated movement of the jaw is essential for catching and swallowing the prey. The majority of the jaw muscles in frogs are supplied by the trigeminal motoneurons. We have previously described that the primary vestibular afferent fibers, conveying information about the movements of the head, established close appositions on the motoneurons of trigeminal nerve providing one of the morphological substrates of monosynaptic sensory modulation of prey-catching behavior in the frog. The aim of our study was to reveal the spatial distribution of vestibular close appositions on the somatodendritic compartments of the functionally different trigeminal motoneurons. In common water frogs, the vestibular and trigeminal nerves were simultaneously labeled with different fluorescent dyes and the possible direct contacts between vestibular afferents and trigeminal motoneurons were identified with the help of DSD2 attached to an Andor Zyla camera. In the rhombencephalon, an overlapping area was detected between the incoming vestibular afferents and trigeminal motoneurons along the whole extent of the trigeminal motor nucleus. The vestibular axon collaterals formed large numbers of close appositions with dorsomedial and ventrolateral dendrites of trigeminal motoneurons. The majority of direct contacts were located on proximal dendritic segments closer than 300 µm to the somata. The identified contacts were evenly distributed on rostral motoneurons innervating jaw-closing muscles and motoneurons supplying jaw-opening muscles and located in the caudal part of trigeminal nucleus. We suggest that the identified contacts between vestibular axon terminals and trigeminal motoneurons may constitute one of the morphological substrates of a very quick response detected in trigeminal motoneurons during head movements.
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Affiliation(s)
- András Birinyi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary.
| | - Nóra Rácz
- Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Szilvia Kecskes
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Clara Matesz
- Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary.,MTA-DE Neuroscience Research Group, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary.,Department of Oral Anatomy, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - Gabriella Kovalecz
- Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
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Kageyama I, Yoshimura K, Satoh Y, Nanayakkara CD, Pallegama RW, Iwasaki SI. Proposal for research and education: joint lectures and practicals on central nervous system anatomy and physiology. J Physiol Sci 2016; 66:283-92. [PMID: 26621026 PMCID: PMC10718038 DOI: 10.1007/s12576-015-0428-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/05/2015] [Indexed: 01/01/2023]
Abstract
We coordinated anatomy and physiology lectures and practicals to facilitate an integrated understanding of morphology and function in a basic medical science program for dental students and to reduce the time spent on basic science education. This method is a means to provide the essential information and skills in less time. The overall impression was that the practice of joint central nervous system lectures and practicals was an efficient method for students, which suggests that joint lectures might also be useful for clinical subjects. About two-thirds of students felt that the joint anatomy and physiology lecture on the central nervous system was useful and necessary in understanding the relationship between morphology and function, at least for this subject. One-third of students were neutral on the effectiveness of this method. However, the survey results suggest that improvements are needed in the method and timing of joint lectures and practicals. The present teaching approach can be further improved by conducting combined lectures in which the form and function of anatomic structures are presented by the relevant departments during the same lecture. Finally, joint lecturers and practicals offer an opportunity to increase student understanding of the importance of new research findings by the present authors and other researchers.
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Affiliation(s)
- Ikuo Kageyama
- Department of Anatomy, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-Cho, Chuo-ku, Niigata, 951-8580, Japan
| | - Ken Yoshimura
- Department of Anatomy, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-Cho, Chuo-ku, Niigata, 951-8580, Japan
| | - Yoshihide Satoh
- Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-Cho, Chuo-Ku, Niigata, 951-8580, Japan
| | - Chinthani D Nanayakkara
- Department of Basic Sciences, Faculty of Dental Sciences, University of Peradeniya, Peradeniya, 20400, Sri Lanka
| | - Ranjith W Pallegama
- Division of Physiology, Department of Basic Sciences, Faculty of Dental Sciences, University of Peradeniya, Peradeniya, 20400, Sri Lanka
| | - Shin-Ichi Iwasaki
- Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-Cho, Chuo-Ku, Niigata, 951-8580, Japan.
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Satoh Y, Ishizuka K, Yajima E, Nagamine Y, Iwasaki SI. Neuronal activities of the vestibular nuclear complex during mechanically induced rhythmic jaw movements in rats. Brain Res Bull 2012; 89:86-91. [PMID: 22828572 DOI: 10.1016/j.brainresbull.2012.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 07/05/2012] [Accepted: 07/07/2012] [Indexed: 01/16/2023]
Abstract
We studied the neuronal activities of the vestibular nuclear complex (VN) neurons during rhythmic jaw movements in rats anesthetized with urethane. Rhythmic jaw movements were induced by mechanical stimulation of the palate mucosa. The firing rate of approximately 25% of VN neurons increased significantly, and that of 10% of VN neurons decreased significantly, during these rhythmic jaw movements. There was no correlation between the change in the firing rate and the phase of the rhythmic jaw movements (jaw-opening and jaw-closing phases). The neurons that were affected were intermingled in the VN. These results suggest that the VN neurons are involved in controlling jaw movements.
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Affiliation(s)
- Yoshihide Satoh
- Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuou-ku, Niigata 951-8580, Japan.
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Satoh Y, Yajima E, Nagamine Y, Ishizuka K, Murakami T. Effects of neck muscle activities during rhythmic jaw movements by stimulation of the medial vestibular nucleus in rats. Brain Res Bull 2011; 86:447-53. [PMID: 21907266 DOI: 10.1016/j.brainresbull.2011.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 07/27/2011] [Accepted: 08/05/2011] [Indexed: 01/15/2023]
Abstract
This study first examines whether there is rhythmic activity of the neck muscles during cortically induced rhythmic jaw movements in rats anesthetized by urethane. Rhythmic jaw movements were induced by repetitive electrical stimulation of the orofacial motor cortex. An electromyogram in the splenius muscles (spEMG) showed rhythmic bursts during the jaw-opening phase, or during the transition from the jaw-opening phase to the jaw-closing phase. In the sternomastoid (stEMG), however, the electromyogram did not show any bursts during rhythmic jaw movements. A further study then examines whether stimulation of the medial vestibular nucleus (MVN) modulates the rhythmic activity of the neck muscles. Stimuli applied in the jaw-closing phase induced a transient burst in the stEMG, and the duration of activity in the spEMG was increased. Stimuli applied in the jaw-opening phase induced a transient burst in the stEMG and an inhibitory period in the spEMG. These results imply that the MVN is involved in the modulation of neck muscle activities during rhythmic jaw movements induced by stimulating the orofacial motor cortex.
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Affiliation(s)
- Yoshihide Satoh
- Department of Physiology, The Nippon Dental University, School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuou-ku, Niigata 951-8580, Japan.
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Guzman-Lopez J, Buisson Y, Strutton PH, Bronstein AM. Interaction between vestibulo-spinal and corticospinal systems: a combined caloric and transcranial magnetic stimulation study. Exp Brain Res 2011; 214:37-45. [PMID: 21805198 DOI: 10.1007/s00221-011-2804-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 07/13/2011] [Indexed: 12/21/2022]
Abstract
We investigated the interaction between vestibular and corticospinal stimuli in 8 healthy volunteers. Vestibular stimulation was induced with unilateral ear caloric irrigation (30°C) with subjects supine. Single transcranial magnetic stimulation (TMS) pulses were delivered (double-cone coil, intensities 60-75% maximal output) every 10-20 s during vestibular activation and during baseline. Bilateral surface electromyography (EMG) from splenius capitis, sternocleidomastoid (SCM), obliquus externus abdominis, vastus lateralis, biceps femoris (BF), tibialis anterior and peroneus longus was obtained. During whole-body maximal rotatory voluntary isometric contraction (MRVC), only SCM and BF displayed EMG activation/inhibition patterns indicating axial rotatory action. TMS-induced motor evoked potentials (MEPs) after caloric irrigation revealed that only SCM showed consistent vestibular-mediated excitation/inhibition responses, i.e. an increase in MEP area contralateral to the irrigation and a decrease in MEP area ipsilaterally (+12.7 and -6.3% of the MRVC, respectively). A putative head turn induced by this SCM activity pattern would be in the same direction of the slow-phase eye movement. EMG in the 100 ms preceding TMS showed muscle tone values of approximately 10% of MRVC. After caloric irrigation, these values increased by ca. 2% for all muscles bilaterally and hence cannot explain the direction-specific SCM MEP changes. Thus, SCM MEPs show caloric-induced amplitude modulation indicating that SCM is under both horizontal semicircular canal and corticospinal control. This vestibular modulation of corticospinal SCM control likely occurs at cortical levels. The direction of the MEP modulation indicates a directional coupling between vestibularly induced head and eye movements.
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Affiliation(s)
- J Guzman-Lopez
- Neuro-Otology Unit, Imperial College London, Charing Cross Hospital, London W6 8RF, UK
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