DOCSLIB.ORG

Afferent Projections of the Trigeminal Nerve in the Goldfish, Carassius Auratus R.L

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Afferent Projections of the Trigeminal Nerve in the Goldfish, Carassius Auratus R.L JOURNAL OF MORPHOLOGY 198:131-147 (1988) Afferent Projections of the Trigeminal Nerve in the Goldfish, Carassius auratus R.L. PUZDROWSKI Department ofBioZogy, The University of Michigan, Ann Arbor. Michigan 48109 ABSTRACT The horseradish peroxidase (HRP) histochemical technique was used to examine the peripheral distribution and afferent projections of the trigeminal nerve in the goldfish, Carassius auratus. Sensory fibers of the trigeminal nerve distribute over the head via four branches. The ophthalmic branch distributes fibers to the region above the eye and naris. The maxillary and mandibular branches innervate the regions of the upper and lower lip, respectively. A fourth branch of the trigeminal nerve was demonstrated to be present in the hyomandibular trunk. Upon entering the medulla the trigeminal afferent fibers divide into a rostro- medially directed bundle and a caudally directed bundle. The rostromedially directed bundle terminates in the sensory trigeminal nucleus (STN) located within the rostral medulla. The majority of fibers turn caudally, forming the descending trigeminal tract. Fibers of the descending trigeminal tract termi- nate within three medullary nuclei: the nucleus of the descending trigeminal tract (NDTV), the spinal trigeminal nucleus (Spv), and the medial funicular nucleus (MFn). All projections, except for those to the MFn, are ipsilateral. Contralateral projections were observed at the level of the MFn following the labeling of the ophthalmic and maxillomandibular branches. All branches of the trigeminal nerve project to all four of the trigeminal medullary nuclei. Projections to the STN and MFn were found to be topographically organized such that the afferents of the ophthalmic branch project onto the ventral portion of these nuclei, while the afferents of the maxillo- and hyomandibular branches project to the dorsal portion of these nuclei. Cells of the mesencephalic trigeminal nucleus were retrogradely labeled following HRP application to the ophthalmic, maxillary, and mandibular branches of the trigeminal nerve. In addition to demonstrating the ascending mesencephalic trigeminal root fibers, HRP application to the above-mentioned branches also revealed descending mesencephalic trigeminal fibers. The de- scending mesencephalic trigeminal fibers course caudally medial to the bran- chiomeric motor column and terminate in the ventromedial portion of the MFn. As in most anamniotic gnathostomes, the '67; Harrison, '81). trigeminal sensory nerve in teleosts consists In teleosts the afferent fibers of the trigem- of maxillomandibular branches, which dis- inal nerve enter the brainstem as a single tribute fibers to the oral region, and an root that distributes fibers to the trigeminal ophthalmic branch, which distributes fibers medullary nuclear complex (Woodburne, '36; to the region dorsal to the orbit and naris. In Luiten, '75). In addition to these sensory af- addition, in teleosts a third branch of the ferents, fibers from the cells of the mesence- trigeminal nerve, termed the ramus com- phalic trigeminal nucleus exit the brainstem municans, has been described coursing pe- through the trigeminal root and course pe- ripherally along the rostral operculum as a ripherally in the branches of the trigeminal part of the hyomandibular trunk (Herrick, nerve. 1899; Allis, '03; Maheshwari, '65; Saxena, There have been relatively few studies uti- G 1988 ALAN R. LISS, INC 132 R.L. PUZDROWSKI lizing modern tracing techniques to investi- trigeminal nucleus. A third specimen (ap- gate the primary afferents of the sensory trigeminal nerve in teleosts. Using degener- A hhreviatwns ation methods to investigate the projections of the entire trigeminal root in the carp (Cy AG anterior ganglion prinus carpw), Luiten ('75) reported that the ALLN root of the anterior lateral line nerve descending trigeminal tract gives off axons ALLNd dorsal root of the anterior lateral line nerve ALLN, ventral root of the anterior lateral line to four different cell groups, which he consid- nerve ered subdivisions of the nucleus of the de- BS bulbospinal tract scending trigeminal tract. There has been Cb cerebellum only a single study of the trigeminal sensory cc cerebellar crest afferents utilizing horseradish peroxidase CL caudal lobe of the cerebellum DTN dorsal tegmental nucleus (HRP) techniques in two species of teleosts, DTV descending trigeminal tract Hypsoblennius and Oxylebius (von Bartheld EG eminentia granularis and Meyer, '85). That study was limited to FL facial lobe Fm facial motor nerve an examination of the afferent projections of FR fasciculus retroflexus the trigeminal nerve branches innervating Fs facial sensory nerve the cirri (finger-like projections found on the HYO hyomandibular trunk dorsal surface of the head in these genera) I11 third ventricle IL inferior lobe of the hypothalamus and its findings agreed, for the most part, I0 infraorbital trunk with the description given by Luiten ('75). IR inferior reticular formation The mesencephalic trigeminal nucleus has Iv fourth ventricle been described in a number of teleosts (Wein- LLF lateral longitudinal fasciculus MA Mauthner axon berg, '28; Woodburne, '36; Luiten, '75, '79). MAN mandibular branch of the infraorbital trunk However, the peripheral distribution of the MAX maxillary branch of the infraorbital trunk afferents of these cells has never been fullv MFn medial funicular nucleus examined, nor has a mesencephalic trigemi- medial longitudinal fasciculus MR medial reticular formation nal root ever been experimentally demon- Mv cells of the mesencephalic trigeminal strated in a teleost. nucleus The purpose of the present study was to nC commissural nucleus of Cajal provide a complete description of the primary Nm nucleus of the descending trigeminal tract NMLF nucleus of the medial longitudinal sensory afferents of the trigeminal nerve in fasciculus a teleost, the goldfish Carassius auratus, uti- oPv ventricle of the optic tectum lizing HRP techniques. An abstract of this OT optic tectum work has been published previously Cpuz- pal palatine ramus of the facial sensory nerve PC posterior commissure drowski, '85). PCT posterior cerebellar tract PG preglomerular complex MATERIALS AND METHODS PN periventricular nucleus of the inferior lobe The results of this study are based on ob- rcl Communicating ramus of the trigeminal nerve servations made using 32 goldfish, C. aura- rosl lateral line ramus of the supraorbital trunk tus, ranging in size from 1-12 cm in total ros, trigeminofacial ramus of the supraorbital length. All surgical and perfusion procedures v+vii trunk otic ramus of the lateral line nerve utilized animals that were anesthetized with Et recurrent ramus of the facial sensory nerve tricaine methane sulfonate (Sigma Chemical ~IIroot of the facial sensory nerve Co., St. Louis, MO). SG secondary gustatory tract Five animals were used for survey pur- SGN secondary gustatory nucleus supraorbital trunk poses. Two specimens were transcardially so spinal trigeminal nucleus perfused with 0.04 M phosphate buffer and superior reticular formation MA(90 ml80% ethanol, 5 ml stock formal- STN sensory trigeminal nucleus dehyde, 5 ml glacial ascetic acid); the brains T dorsal thalamus torus longitudinalis were removed, embedded in Paraplast &an- :L root of the trigeminal nerve cer, Distributors, St. Louis, MO), and serially Val" valvula of the cerebellum sectioned in the transverse plane at 10 pm. VII root of the facial sensory nerve These sectioned brains were subsequently VIIm facial motor nucleus vagal lobe stained with cresyl violet and used to exam- ;k trigeminal motor nucleus ine the normal anatomy of the brainstem Xm vagal motor nucleus trigeminal centers and the mesencephalic XN vagus nerve Fig. 1. Lateral view of the head of Carassius auratus HRP application. The outline of the brain is indicated illustrating the distribution of the supraorhital, infraor- by dots; the outline of the body is indicated by dashes. hital, and hyomandihular nerve trunks over the head. Bar scale = 1 mm. Arrowheads indicate points of nerve transection and proximately 1 cm in length) was prepared Hawk International, Distributors, Montreal, according to the Bodian reduced silver pro- Canada). The location of HRP application to cedure and used to examine the peripheral each trunk is illustrated in Figure 1. When distribution of the main nerve trunks carry- labeling the nerves that course along the ing trigeminal rami. The peripheral distri- walls of the orbit (SO, 10, MAX, and MAN, bution of the nerve trunks of the head was see Fig. 1) the eyeball was retracted, the also examined in two specimens that had nerve transected and labeled with HRP, and been prepared by a modification of the Sihler the eyeball then replaced and covered with technique (Freihofer, '66). Specimens pro- histoacryl. The hyomandibular trunk was cessed by this technique are rendered trans- transected and labeled with HRP at the point parent, except for the nerves, which are in the rostrodorsal wall of the opercular cav- stained a dark purple. ity where it courses superficially before en- Surgical procedures were performed with tering the hyomandibular bone. The palatine the aid of a Zeiss stereozoom operating mi- ramus was labeled with HRP at a point croscope. Following anesthetization, the fish where it courses along the posterior wall of was wrapped in moistened cheesecloth and the orbit in order to establish that it was a individual nerve trunks were exposed and branch of the facial sensory nerve containing
Load more

Recommended publications
  • Projections from the Trigeminal Nuclear Complex to the Cochlear Nuclei: a Retrograde and Anterograde Tracing Study in the Guinea Pig
    Journal of Neuroscience Research 78:901–907 (2004) Projections From the Trigeminal Nuclear Complex to the Cochlear Nuclei: a Retrograde and Anterograde Tracing Study in the Guinea Pig Jianxun Zhou and Susan Shore* Department of Otolaryngology and Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan In addition to input from auditory centers, the cochlear cuneate nucleus innervation of cochlear nucleus has been nucleus (CN) receives inputs from nonauditory centers, hypothesized to convey information about head and pinna including the trigeminal sensory complex. The detailed position for the purpose of localizing a sound source in anatomy, however, and the functional implications of the space (Young et al., 1995). In addition, interactions be- nonauditory innervation of the auditory system are not tween somatosensory and auditory systems have been fully understood. We demonstrated previously that the linked increasingly to phantom sound perception, also trigeminal ganglion projects to CN, with terminal labeling known as tinnitus. This is demonstrated in the observa- most dense in the marginal cell area and secondarily in tions that injuries of the head and neck region can lead to the magnocellular area of the ventral cochlear nucleus the onset of tinnitus in patients with no hearing loss (VCN). We continue this line of study by investigating the (Lockwood et al., 1998). projection from the spinal trigeminal nucleus to CN in We demonstrated previously projections from the guinea pig. After injections of the retrograde tracers Flu- trigeminal ganglion to CN in guinea pigs (Shore et al., oroGold or biotinylated dextran amine (BDA) in VCN, 2000). Terminal labeling of trigeminal ganglion projec- labeled cells were found in the spinal trigeminal nuclei, tions to the CN was found to be most dense in the most densely in the pars interpolaris and pars caudalis marginal cell area and secondarily in the magnocellular with ipsilateral dominance.
    [Show full text]
  • Cranial Nerve Palsy
    Cranial Nerve Palsy What is a cranial nerve? Cranial nerves are nerves that lead directly from the brain to parts of our head, face, and trunk. There are 12 pairs of cranial nerves and some are involved in special senses (sight, smell, hearing, taste, feeling) while others control muscles and glands. Which cranial nerves pertain to the eyes? The second cranial nerve is called the optic nerve. It sends visual information from the eye to the brain. The third cranial nerve is called the oculomotor nerve. It is involved with eye movement, eyelid movement, and the function of the pupil and lens inside the eye. The fourth cranial nerve is called the trochlear nerve and the sixth cranial nerve is called the abducens nerve. They each innervate an eye muscle involved in eye movement. The fifth cranial nerve is called the trigeminal nerve. It provides facial touch sensation (including sensation on the eye). What is a cranial nerve palsy? A palsy is a lack of function of a nerve. A cranial nerve palsy may cause a complete or partial weakness or paralysis of the areas served by the affected nerve. In the case of a cranial nerve that has multiple functions (such as the oculomotor nerve), it is possible for a palsy to affect all of the various functions or only some of the functions of that nerve. What are some causes of a cranial nerve palsy? A cranial nerve palsy can occur due to a variety of causes. It can be congenital (present at birth), traumatic, or due to blood vessel disease (hypertension, diabetes, strokes, aneurysms, etc).
    [Show full text]
  • Circuits in the Rodent Brainstem That Control Whisking in Concert with Other Orofacial Motor Actions
    Neuroscience 368 (2018) 152–170 CIRCUITS IN THE RODENT BRAINSTEM THAT CONTROL WHISKING IN CONCERT WITH OTHER OROFACIAL MOTOR ACTIONS y y LAUREN E. MCELVAIN, a BETH FRIEDMAN, a provides the reset to the relevant premotor oscillators. HARVEY J. KARTEN, b KAREL SVOBODA, c FAN WANG, d Third, direct feedback from somatosensory trigeminal e a,f,g MARTIN DESCHEˆ NES AND DAVID KLEINFELD * nuclei can rapidly alter motion of the sensors. This feed- a Department of Physics, University of California at San Diego, back is disynaptic and can be tuned by high-level inputs. La Jolla, CA 92093, USA A holistic model for the coordination of orofacial motor actions into behaviors will encompass feedback pathways b Department of Neurosciences, University of California at San Diego School of Medicine, La Jolla, CA 92093, USA through the midbrain and forebrain, as well as hindbrain c areas. Howard Hughes Medical Institute, Janelia Research This article is part of a Special Issue entitled: Barrel Campus, Ashburn, VA 20147, USA Cortex. Ó 2017 IBRO. Published by Elsevier Ltd. All rights d Department of Neurobiology, Duke University Medical reserved. Center, Durham, NC 27710, USA e Department of Psychiatry and Neuroscience, Laval University, Que´bec City, G1J 2G3, Canada f Key words: coupled oscillators, facial nucleus, hypoglossal Section of Neurobiology, University of California at San Diego, La Jolla, CA 92093, USA nucleus, licking, orienting, tongue, vibrissa. g Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, CA 92093, USA Contents Introduction 153 Abstract—The world view of rodents is largely determined Coordination of multiple orofacial motor actions 153 by sensation on two length scales.
    [Show full text]
  • MR Imaging of Primary Trochlear Nerve Neoplasms
    707 MR Imaging of Primary Trochlear Nerve Neoplasms Lindell R. Gentry 1 We present the clinical, anatomic, and MR imaging findings in six patients with seven Rahul C. Mehta 1 primary trochlear nerve neoplasms, as well as the MR and clinical criteria that serve to Richard E. Appen2 establish the diagnosis of these rare cranial nerve neoplasms. Three patients had a Joel M. Weinstein2 history of neurofibromatosis and five patients had clinical evidence of a trochlear nerve palsy. Six of seven neoplasms produced localized, fusiform enlargement of the proximal cisternal segments of the trochlear nerves. The lesions that were visible on noncontrast MR scans (T1-, T2-, and proton density-weighted) had signal intensities that were virtually identical to normal brain parenchyma. All lesions showed intense, homogeneous enhancement on contrast-enhanced scans. Contrast-enhanced imaging was necessary for the detection of five of seven lesions and greatly increased the value of the MR study in all six patients. AJNR 12:707-713, July/August 1991; AJR 157: September 1991 Primary neoplasms arising from pure motor cranial nerves such as the trochlear nerve are rare. To our knowledge just nine primary trochlear nerve neoplasms have been reported in the literature [1-7), only one of which was imaged with MR [1). Over the last 6 years, since we began to use MR as the primary imaging method for evaluating patients with cranial nerve palsies , we have noticed a striking increase in the number of primary trochlear nerve neoplasms over those encountered during the CT era. We believe this is due to a much greater sensitivity of MR in detecting these typically small lesions.
    [Show full text]
  • DR. Sanaa Alshaarawy
    By DR. Sanaa Alshaarawy 1 By the end of the lecture, students will be able to : Distinguish the internal structure of the components of the brain stem in different levels and the specific criteria of each level. 1. Medulla oblongata (closed, mid and open medulla) 2. Pons (caudal, mid “Trigeminal level” and rostral). 3. Mid brain ( superior and inferior colliculi). Describe the Reticular formation (structure, function and pathway) being an important content of the brain stem. 2 1. Traversed by the Central Canal. Motor Decussation*. Spinal Nucleus of Trigeminal (Trigeminal sensory nucleus)* : ➢ It is a larger sensory T.S of Caudal part of M.O. nucleus. ➢ It is the brain stem continuation of the Substantia Gelatinosa of spinal cord 3 The Nucleus Extends : Through the whole length of the brain stem and upper segments of spinal cord. It lies in all levels of M.O, medial to the spinal tract of the trigeminal. It receives pain and temperature from face, forehead. Its tract present in all levels of M.O. is formed of descending fibers that terminate in the trigeminal nucleus. 4 It is Motor Decussation. Formed by pyramidal fibers, (75-90%) cross to the opposite side They descend in the Decuss- = crossing lateral white column of the spinal cord as the lateral corticospinal tract. The uncrossed fibers form the ventral corticospinal tract. 5 Traversed by Central Canal. Larger size Gracile & Cuneate nuclei, concerned with proprioceptive deep sensations of the body. Axons of Gracile & Cuneate nuclei form the internal arcuate fibers; decussating forming Sensory Decussation. Pyramids are prominent ventrally. 6 Formed by the crossed internal arcuate fibers Medial Leminiscus: Composed of the ascending internal arcuate fibers after their crossing.
    [Show full text]
  • University International
    INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or “target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy. Unless we meant to delete copyrighted materials that should not have been filmed, you will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photo­ graphed the photographer has followed a definite method in “sectioning” the material. It is customary to begin filming at the upper left hand corner of a large sheet and to continue from left to right in equal sections with small overlaps. If necescary, sectioning is continued again—beginning below the first row and continuing on until complete. 4. For any illustrations that cannot be reproduced satisfactorily by xerography, photographic prints can be purchased at additional cost and tipped into your xerographic copy.
    [Show full text]
  • Trigeminal Nerve Block
    Trigeminal Nerve Block Why use this treatment? This procedure is used for trigeminal neuralgia, described by many patients as one of the most painful afflictions known. TN sufferers experience sudden attacks of pain that are typically brief, but severe. TN pain occurs on only one side, involving the upper, middle and/or lower portions of the face. Attacks may come on without warning or be triggered by specific light stimulation in the affected area of the face. Common triggers include touch, talking, eating, drinking, chewing, tooth brushing, hair combing, water from a shower and even kissing. There are a number of causes for trigeminal neuralgia, including pressure from blood vessels on the trigeminal nerve, multiple sclerosis, brain tumors, or injury to the nerve from head trauma, dental or sinus trauma or from failed procedures that were intended to treat the neuralgia. TN pain after traumatic injury is usually constant aching or burning, but can also get worse with exposure to wind or cold. How does a trigeminal nerve block work? A trigeminal nerve block delivers steroids and/or local anesthetic directly into the space around the trigeminal nerve root. The area is bathed in the medicine. The injection is given to reduce inflammation and provide pain relief for several days to several months. How is the procedure done? You will be placed on an x-ray table and your skin will be cleansed and prepared. This procedure is performed under local anesthetic with light IV sedation. A needle is inserted into the skin beside the mouth, and directed through an opening at the base of the skull.
    [Show full text]
  • Brain Structure and Function Related to Headache
    Review Cephalalgia 0(0) 1–26 ! International Headache Society 2018 Brain structure and function related Reprints and permissions: sagepub.co.uk/journalsPermissions.nav to headache: Brainstem structure and DOI: 10.1177/0333102418784698 function in headache journals.sagepub.com/home/cep Marta Vila-Pueyo1 , Jan Hoffmann2 , Marcela Romero-Reyes3 and Simon Akerman3 Abstract Objective: To review and discuss the literature relevant to the role of brainstem structure and function in headache. Background: Primary headache disorders, such as migraine and cluster headache, are considered disorders of the brain. As well as head-related pain, these headache disorders are also associated with other neurological symptoms, such as those related to sensory, homeostatic, autonomic, cognitive and affective processing that can all occur before, during or even after headache has ceased. Many imaging studies demonstrate activation in brainstem areas that appear specifically associated with headache disorders, especially migraine, which may be related to the mechanisms of many of these symptoms. This is further supported by preclinical studies, which demonstrate that modulation of specific brainstem nuclei alters sensory processing relevant to these symptoms, including headache, cranial autonomic responses and homeostatic mechanisms. Review focus: This review will specifically focus on the role of brainstem structures relevant to primary headaches, including medullary, pontine, and midbrain, and describe their functional role and how they relate to mechanisms
    [Show full text]
  • Clinical Anatomy of the Trigeminal Nerve
    Clinical Anatomy of Trigeminal through the superior orbital fissure Nerve and courses within the lateral wall of the cavernous sinus on its way The trigeminal nerve is the fifth of to the trigeminal ganglion. the twelve cranial nerves. Often Ophthalmic Nerve is formed by the referred to as "the great sensory union of the frontal nerve, nerve of the head and neck", it is nasociliary nerve, and lacrimal named for its three major sensory nerve. Branches of the ophthalmic branches. The ophthalmic nerve nerve convey sensory information (V1), maxillary nerve (V2), and from the skin of the forehead, mandibular nerve (V3) are literally upper eyelids, and lateral aspects "three twins" carrying information of the nose. about light touch, temperature, • The maxillary nerve (V2) pain, and proprioception from the enters the middle cranial fossa face and scalp to the brainstem. through foramen rotundum and may or may not pass through the • The three branches converge on cavernous sinus en route to the the trigeminal ganglion (also called trigeminal ganglion. Branches of the semilunar ganglion or the maxillary nerve convey sensory gasserian ganglion), which contains information from the lower eyelids, the cell bodies of incoming sensory zygomae, and upper lip. It is nerve fibers. The trigeminal formed by the union of the ganglion is analogous to the dorsal zygomatic nerve and infraorbital root ganglia of the spinal cord, nerve. which contain the cell bodies of • The mandibular nerve (V3) incoming sensory fibers from the enters the middle cranial fossa rest of the body. through foramen ovale, coursing • From the trigeminal ganglion, a directly into the trigeminal single large sensory root enters the ganglion.
    [Show full text]
  • Cortical Control of Facial Expression
    Review The Journal of Comparative Neurology Research in Systems Neuroscience DOI 10.1002/cne.23908 Topical review Cortical control of facial expression. René M. Müri1,2,3 1Division of Cognitive and Restorative Neurology, Departments of Neurology and Clinical Research, University Hospital Inselspital, Bern, Switzerland 2Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland 3Center for Cognition, Learning, and Memory, University of Bern, Bern, Switzerland Abbreviated title: Cortical control of facial expression Key words: human, facial expression, emotion, facial innervation | downloaded: 13.3.2017 http://boris.unibe.ch/72088/ This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as an ‘Accepted Article’, doi: 10.1002/cne.23908 source: © 2015 Wiley Periodicals, Inc. Received: Jan 31, 2015; Revised: Sep 19, 2015; Accepted: Sep 25, 2015 This article is protected by copyright. All rights reserved. Journal of Comparative Neurology Page 4 of 23 Abstract The present topical review deals with the motor control of facial expressions in humans. Facial expressions are a central part of human communication. Emotional face expressions have a crucial role in human non-verbal behavior, allowing a rapid transfer of information between individuals. Facial expressions can be both voluntarily or emotionally controlled. Recent studies in non-human primates and humans revealed that the motor control of facial expressions has a distributed neural representation. At least 5 cortical regions on the medial and lateral aspects of each hemisphere are involved: the primary motor cortex, the ventral lateral premotor cortex, the supplementary motor area on the medial wall, and, finally, the rostral and caudal cingulate cortex.
    [Show full text]
  • Somatotopic Organization of Perioral Musculature Innervation Within the Pig Facial Motor Nucleus
    Original Paper Brain Behav Evol 2005;66:22–34 Received: September 20, 2004 Returned for revision: November 10, 2004 DOI: 10.1159/000085045 Accepted after revision: December 7, 2004 Published online: April 8, 2005 Somatotopic Organization of Perioral Musculature Innervation within the Pig Facial Motor Nucleus Christopher D. Marshall a Ron H. Hsu b Susan W. Herring c aTexas A&M University at Galveston, Galveston, Tex., bDepartment of Pediatric Dentistry, University of North Carolina, Chapel Hill, N.C., and cDepartment of Orthodontics, University of Washington, Seattle, Wash., USA Key Words pools of the lateral 4 of the 7 subnuclei of the facial motor Somatotopy W Innervation W Facial nucleus W Perioral nucleus. The motor neuron pools of the perioral muscles muscles W Orbicularis oris W Buccinator W Mammals were generally segregated from motoneurons innervat- ing other facial muscles of the rostrum. However, motor neuron pools were not confined to single nuclei but Abstract instead spanned across 3–4 subnuclei. Perioral muscle The orbicularis oris and buccinator muscles of mammals motor neuron pools overlapped but were organized so- form an important subset of the facial musculature, the matotopically. Motor neuron pools of portions of the perioral muscles. In many taxa, these muscles form a SOO overlapped greatly with each other but exhibited a robust muscular hydrostat capable of highly manipula- crude somatotopy within the SOO motor neuron pool. tive fine motor movements, likely accompanied by a spe- The large and somatotopically organized SOO motor cialized pattern of innervation. We conducted a retro- neuron pool in pigs suggests that the upper lip might be grade nerve-tracing study of cranial nerve (CN) VII in pigs more richly innervated than the other perioral muscles (Sus scrofa) to: (1) map the motor neuron pool distribu- and functionally divided.
    [Show full text]
  • Monosynaptic Premotor Circuit Tracing Reveals Neural Substrates for Oro-Motor Coordination
    1 Title 2 3 Monosynaptic Premotor Circuit Tracing Reveals Neural Substrates 4 for Oro-motor Coordination 5 6 7 8 9 10 11 Authors and affiliations 12 13 Edward Stanek IV1, Steven Cheng1, Jun Takatoh1, Bao-Xia Han1, and Fan Wang1, 2 * 14 15 1. Department of Neurobiology, Duke University Medical Center, Durham, NC 27710. 16 2. Department of Cell Biology, Duke University Medical Center, Durham, NC 27710. 17 18 19 20 21 22 Corresponding author 23 24 *Fan Wang 25 Department of Neurobiology, Box 3209 26 Duke University Medical Center 27 Durham, NC 27710 28 Phone: 919-684-3682 29 e-mail: [email protected] 30 31 Number of pages: 59 32 Number of Figures: 10 33 Number of Movies: 4 34 Number of Tables: 2 35 Number of words, Abstract: 237 36 Number of words, Main Text: 5,168 1 37 ABSTRACT 38 39 Feeding behaviors require intricately coordinated activation among the muscles of the jaw, 40 tongue, and face, but the neural anatomical substrates underlying such coordination remain 41 unclear. Here we investigate whether the premotor circuitry of jaw and tongue motoneurons 42 contain elements for coordination. Using a modified monosynaptic rabies virus based 43 transsynaptic tracing strategy, we systematically mapped premotor neurons for the jaw-closing 44 masseter muscle and the tongue-protruding genioglossus muscle. The maps revealed that the two 45 groups of premotor neurons are distributed in regions implicated in rhythmogenesis, descending 46 motor control, and sensory feedback. Importantly, we discovered several premotor connection 47 configurations that are ideally suited for coordinating bilaterally symmetric jaw movements, and 48 for enabling co-activation of specific jaw, tongue, and facial muscles.
    [Show full text]