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Ziolkowski LH, Gracheva EO, Bagriantsev SN. Tactile sensation in birds: Physiological insights from avian mechanoreceptors. Curr Opin Neurobiol 2022; 74:102548. [PMID: 35489134 DOI: 10.1016/j.conb.2022.102548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 03/15/2022] [Accepted: 03/27/2022] [Indexed: 12/18/2022]
Abstract
The sense of touch is ubiquitous in vertebrates and relies upon the detection of mechanical forces in the skin by the tactile end-organs of low-threshold mechanoreceptors. Significant progress has been made in understanding the mechanism of tactile end-organ function using mammalian models, but the detailed mechanics of touch sensation in Meissner and Pacinian corpuscles, the principal detectors of transient touch and vibration, remain obscure. The avian homologs of these corpuscles present an opportunity for functional study of mechanosensation in these structures, due to their relative accessibility and high abundance in the bill skin of tactile-foraging waterfowl. Here, we review the current knowledge of mechanosensory end-organs in birds and highlight the utility of the avian model to understand general principles of touch detection in the glabrous skin of vertebrates.
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Affiliation(s)
- Luke H Ziolkowski
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA.
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2
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Eldridge SA, Mortazavi F, Rice FL, Ketten DR, Wiley DN, Lyman E, Reidenberg JS, Hanke FD, DeVreese S, Strobel SM, Rosene DL. Specializations of somatosensory innervation in the skin of humpback whales (Megaptera novaeangliae). Anat Rec (Hoboken) 2022; 305:514-534. [PMID: 35023618 DOI: 10.1002/ar.24856] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 11/12/2022]
Abstract
Cetacean behavior and life history imply a role for somatosensory detection of critical signals unique to their marine environment. As the sensory anatomy of cetacean glabrous skin has not been fully explored, skin biopsy samples of the flank skin of humpback whales were prepared for general histological and immunohistochemical (IHC) analyses of innervation in this study. Histology revealed an exceptionally thick epidermis interdigitated by numerous, closely spaced long, thin diameter penicillate dermal papillae (PDP). The dermis had a stratified organization including a deep neural plexus (DNP) stratum intermingled with small arteries that was the source of intermingled nerves and arterioles forming a more superficial subepidermal neural plexus (SNP) stratum. The patterns of nerves branching through the DNP and SNP that distribute extensive innervation to arteries and arterioles and to the upper dermis and PDP provide a dense innervation associated through the whole epidermis. Some NF-H+ fibers terminated at the base of the epidermis and as encapsulated endings in dermal papillae similar to Merkel innervation and encapsulated endings seen in terrestrial mammals. However, unlike in all mammalian species assessed to date, an unusual acellular gap was present between the perineural sheaths and the central core of axons in all the cutaneous nerves perhaps as mechanism to prevent high hydrostatic pressure from compressing and interfering with axonal conductance. Altogether the whale skin has an exceptionally dense low-threshold mechanosensory system innervation most likely adapted for sensing hydrodynamic stimuli, as well as nerves that can likely withstand high pressure experienced during deep dives.
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Affiliation(s)
- Sherri A Eldridge
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, USA.,Biology Department, University of Massachusetts Dartmouth, Dartmouth, Massachusetts, USA
| | - Farzad Mortazavi
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Frank L Rice
- Integrated Tissue Dynamics, Rensselaer, New York, USA
| | - Darlene R Ketten
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - David N Wiley
- National Oceanic and Atmospheric Administration/ National Ocean Service/Stellwagen Bank National Marine Sanctuary, Scituate, Massachusetts, USA
| | - Ed Lyman
- Hawaiian Islands Humpback Whale National Marine Sanctuary, Kihei, Hawaii, USA
| | - Joy S Reidenberg
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Frederike D Hanke
- University of Rostock, Institute for Biosciences, Neuroethology, Rostock, Germany
| | - Steffen DeVreese
- Department of Comparative Biomedicine and Food Science, University of Padova, Padova, Italy.,Laboratory of Applied Bioacoustics, Technical University of Catalonia, BarcelonaTech, Barcelona, Spain
| | - Sarah McKay Strobel
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Douglas L Rosene
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, USA
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3
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Tactile sensitivity in the rat: a correlation between receptor structure and function. Exp Brain Res 2021; 239:3457-3469. [PMID: 34519842 PMCID: PMC8599332 DOI: 10.1007/s00221-021-06193-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/11/2021] [Indexed: 11/04/2022]
Abstract
Single cutaneous fibers were recorded in the median nerve of the deeply anesthetized rat and the receptor morphology in the forelimb glabrous skin was analyzed to establish a probable correlation between receptor anatomy and physiology. Receptor complexes in the glabrous skin of the rat forelimb were stained immunologically with antibodies NF-200 and PGP-9.5, confirming the presence of Meissner corpuscles and Merkel complexes within the dermal papilla similar to other mammals including primates. Both the Meissner corpuscles and Merkel cell complexes were sparse and located in the pyramidal-shaped palmer pads and the apex of the digit extremities. They were almost totally absent elsewhere in the glabrous skin. No Ruffini receptors or Pacinian corpuscles were found in our samples. A total of 92 cutaneous fibers were retained long enough for analysis. Thirty-five (38%) were characterized as rapidly adapting fibers (RA) and 57 (62%) were slowly adapting afferents (SA). Despite the very limited number of receptors at the tip of the digit, RA receptors outnumbered SA fibers 3.2/1.0. In contrast, SA fibers on the thenar pad outnumbered RA receptors by a ratio of 3–1. Despite the very limited number of low threshold mechanoreceptors in the glabrous skin of the rat forelimb, the prevalence of SA afferents in the palm and more frequent occurrence of RA afferents in the digit extremity suggest differences in functionality both for locomotion and object manipulation.
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Handler A, Ginty DD. The mechanosensory neurons of touch and their mechanisms of activation. Nat Rev Neurosci 2021; 22:521-537. [PMID: 34312536 PMCID: PMC8485761 DOI: 10.1038/s41583-021-00489-x] [Citation(s) in RCA: 120] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2021] [Indexed: 02/07/2023]
Abstract
Our sense of touch emerges from an array of mechanosensory structures residing within the fabric of our skin. These tactile end organ structures convert innocuous forces acting on the skin into electrical signals that propagate to the CNS via the axons of low-threshold mechanoreceptors (LTMRs). Our rich capacity for tactile discrimination arises from the dissimilar intrinsic properties of the LTMR subtypes that innervate different regions of the skin and the structurally distinct end organ complexes with which they associate. These end organ structures comprise a range of non-neuronal cell types, which may themselves actively contribute to the transformation of tactile forces into neural impulses within the LTMR afferents. Although the mechanism and the site of transduction across end organs remain unclear, PIEZO2 has emerged as the principal mechanosensitive channel involved in light touch of the skin. Here we review the physiological properties of LTMR subtypes and discuss how features of their cutaneous end organ complexes shape subtype-specific tuning.
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Affiliation(s)
- Annie Handler
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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5
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Strobel SM, Miller MA, Murray MJ, Reichmuth C. Anatomy of the sense of touch in sea otters: Cutaneous mechanoreceptors and structural features of glabrous skin. Anat Rec (Hoboken) 2021; 305:535-555. [PMID: 34425043 DOI: 10.1002/ar.24739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 05/06/2021] [Accepted: 05/27/2021] [Indexed: 11/08/2022]
Abstract
Sea otters (Enhydra lutris) demonstrate rapid, accurate tactile abilities using their paws and facial vibrissae. Anatomical investigations of neural organization in the vibrissal bed and somatosensory cortex coincide with measured sensitivity, but no studies describe sensory receptors in the paws or other regions of glabrous (i.e., hairless) skin. In this study, we use histology to assess the presence, density, and distribution of mechanoreceptors in the glabrous skin of sea otters: paws, rhinarium, lips, and flipper digits, and we use scanning electron microscopy to describe skin-surface texture and its potential effect on the transduction of mechanical stimuli. Our results confirm the presence of Merkel cells and Pacinian corpuscles, but not Meissner corpuscles, in all sea otter glabrous skin. The paws showed the highest density of Merkel cells and Pacinian corpuscles. Within the paw, relative densities of mechanoreceptor types were highest in the distal metacarpal pad and digits, which suggests that the distal paw is a tactile fovea for sea otters. In addition to the highest receptor density, the paw displayed the thickest epidermis. Rete ridges (epidermal projections into the dermis) and dermal papillae (dermal projections into the epidermis) were developed across all glabrous skin. These quantitative and qualitative descriptions of neural organization and physical features, combined with previous behavioral results, contribute to our understanding of how structure relates to function in the tactile modality. Our findings coincide with behavioral observations of sea otters, which use touch to maintain thermoregulatory integrity of their fur, explore objects, and capture visually cryptic prey.
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Affiliation(s)
- Sarah McKay Strobel
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Melissa A Miller
- California Department of Fish and Wildlife, Marine Wildlife Veterinary Care and Research Center, Santa Cruz, California, USA
| | | | - Colleen Reichmuth
- Long Marine Laboratory, Institute of Marine Sciences, Santa Cruz, California, USA
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Moayedi Y, Michlig S, Park M, Koch A, Lumpkin EA. Somatosensory innervation of healthy human oral tissues. J Comp Neurol 2021; 529:3046-3061. [PMID: 33786834 PMCID: PMC10052750 DOI: 10.1002/cne.25148] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 12/15/2022]
Abstract
The oral somatosensory system relays essential information about mechanical stimuli to enable oral functions such as feeding and speech. The neurochemical and anatomical diversity of sensory neurons across oral cavity sites have not been systematically compared. To address this gap, we analyzed healthy human tongue and hard-palate innervation. Biopsies were collected from 12 volunteers and underwent fluorescent immunohistochemistry (≥2 specimens per marker/structure). Afferents were analyzed for markers of neurons (βIII tubulin), myelinated afferents (neurofilament heavy, NFH), and Merkel cells and taste cells (keratin 20, K20). Hard-palate innervation included Meissner corpuscles, glomerular endings, Merkel cell-neurite complexes, and free nerve endings. The organization of these somatosensory endings is reminiscent of fingertips, suggesting that the hard palate is equipped with a rich repertoire of sensory neurons for pressure sensing and spatial localization of mechanical inputs, which are essential for speech production and feeding. Likewise, the tongue is innervated by afferents that impart it with exquisite acuity and detection of moving stimuli that support flavor construction and speech. Filiform papillae contained end bulbs of Krause, as well as endings that have not been previously reported, including subepithelial neuronal densities, and NFH+ neurons innervating basal epithelia. Fungiform papillae had Meissner corpuscles and densities of NFH+ intraepithelial neurons surrounding taste buds. The differing compositions of sensory endings within filiform and fungiform papillae suggest that these structures have distinct roles in mechanosensation. Collectively, this study has identified previously undescribed neuronal endings in human oral tissues and provides an anatomical framework for understanding oral mechanosensory functions.
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Affiliation(s)
- Yalda Moayedi
- Department of Physiology and Cellular Biophysics, Columbia University, New York, New York, USA.,Department of Neurology, Columbia University, New York, New York, USA.,Department of Otolaryngology-Head and Neck Surgery, Columbia University, New York, New York, USA
| | | | - Mark Park
- Oral and Maxillofacial Surgery, New York Presbyterian, Columbia University, New York, New York, USA
| | - Alia Koch
- Oral and Maxillofacial Surgery, New York Presbyterian, Columbia University, New York, New York, USA
| | - Ellen A Lumpkin
- Department of Physiology and Cellular Biophysics, Columbia University, New York, New York, USA.,Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California, USA
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Wai V, Roberts L, Michaud J, Bent LR, Clark AL. The Anatomical Distribution of Mechanoreceptors in Mouse Hind Paw Skin and the Influence of Integrin α1β1 on Meissner-Like Corpuscle Density in the Footpads. Front Neuroanat 2021; 15:628711. [PMID: 33737870 PMCID: PMC7960770 DOI: 10.3389/fnana.2021.628711] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/01/2021] [Indexed: 12/19/2022] Open
Abstract
Afferent neurons and their mechanoreceptors provide critical sensory feedback for gait. The anatomical distribution and density of afferents and mechanoreceptors influence sensory feedback, as does mechanoreceptor function. Electrophysiological studies of hind paw skin reveal the different types of afferent responses and their receptive fields, however, the anatomical distribution of mechanoreceptor endings is unknown. Also, the role of integrin α1β1 in mechanoreceptor function is unclear, though it is expressed by keratinocytes in the stratum basale where it is likely involved in a variety of mechanotransduction pathways and ion channel functionalities. For example, it has been shown that integrin α1β1 is necessary for the function of TRPV4 that is highly expressed by afferent units. The purpose of this study, therefore, was to determine and compare the distribution of mechanoreceptors across the hind paw skin and the footfall patterns of itga1-null and wild type mice. The itga1-null mouse is lacking the integrin α1 subunit, which binds exclusively to the β1 subunit, thus rendering integrin α1β1 nonfunctional while leaving the numerous other pairings of the β1 subunit undisturbed. Intact hind paws were processed, serially sectioned, and stained to visualize mechanoreceptors. Footfall patterns were analyzed as a first step in correlating mechanoreceptor distribution and functionality. Merkel cells and Meissner-like corpuscles were present, however, Ruffini endings and Pacinian corpuscles were not observed. Meissner-like corpuscles were located exclusively in the glabrous skin of the footpads and digit tips, however, Merkel cells were found throughout hairy and glabrous skin. The increased density of Merkel cells and Meissner-like corpuscles in footpads 1 and 3 and Meissner-like corpuscles in footpad 4 suggests their role in anteroposterior balance, while Meissner-like corpuscle concentrations in digits 2 and 5 support their role in mediolateral balance. Finally, a larger density of Meissner-like corpuscles in footpads 3 and 4 in male itga1-null mice compared to wild type controls paves the way for future site-specific single fiber in vivo recordings to provide insight into the role of integrin α1β1 in tactile mechanotransduction.
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Affiliation(s)
- Valerie Wai
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - Lauren Roberts
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - Jana Michaud
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - Leah R Bent
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - Andrea L Clark
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, Canada
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8
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Cobo R, García‐Mesa Y, Cárcaba L, Martin‐Cruces J, Feito J, García‐Suárez O, Cobo J, García‐Piqueras J, Vega JA. Verification and characterisation of human digital Ruffini's sensory corpuscles. J Anat 2021; 238:13-19. [PMID: 32864772 PMCID: PMC7754963 DOI: 10.1111/joa.13301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/05/2020] [Accepted: 08/05/2020] [Indexed: 01/03/2023] Open
Abstract
Ruffini's corpuscles are present as long fusiform encapsulated sensory structures in different tissues including the skin. Although physiological analyses strongly suggest their existence in glabrous digital skin, such localisation remains unconfirmed. Here, we have investigated the occurrence of typical Ruffini's corpuscles in 372 sections of human digital skin obtained from 186 subjects of both sexes and different ages (19-92 years). S100 protein, neuron-specific enolase and neurofilament proteins were detected, and the basic immunohistochemical profile of these corpuscles was analysed. Fewer than 0.3 Ruffini's corpuscles/mm2 were detected, with density distribution across the fingers being F4 > F3 > F2 > F1 > F5 and absolute values being F2 > F1 > F3 > F4 > F5. Axons displayed neuron-specific enolase immunoreactivity, glial cells forming the core contained S100 protein, and the capsule was positive for CD34 but not Glut1, demonstrating an endoneurial origin. Present results demonstrate the existence of Ruffini's corpuscles in human glabrous digital skin at very low densities. Moreover, the identified Ruffini's corpuscles share the basic immunohistochemical characteristics of other dermal sensory corpuscles.
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Affiliation(s)
- Ramón Cobo
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Yolanda García‐Mesa
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Lucía Cárcaba
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - José Martin‐Cruces
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Jorge Feito
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain,Servicio de Anatomía PatológicaComplejo Hospitalario Universitario de SalamancaSalamancaSpain
| | - Olivia García‐Suárez
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Juan Cobo
- Departamento de Cirugía y Especialidades Médico‐QuirúrgicasUniversidad de OviedoOviedoSpain,Instituto Asturiano de OdontologíaOviedoSpain
| | - Jorge García‐Piqueras
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - José A. Vega
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain,Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile
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9
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Peripheral Mechanobiology of Touch-Studies on Vertebrate Cutaneous Sensory Corpuscles. Int J Mol Sci 2020; 21:ijms21176221. [PMID: 32867400 PMCID: PMC7504094 DOI: 10.3390/ijms21176221] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/19/2020] [Accepted: 08/24/2020] [Indexed: 12/21/2022] Open
Abstract
The vertebrate skin contains sensory corpuscles that are receptors for different qualities of mechanosensitivity like light brush, touch, pressure, stretch or vibration. These specialized sensory organs are linked anatomically and functionally to mechanosensory neurons, which function as low-threshold mechanoreceptors connected to peripheral skin through Aβ nerve fibers. Furthermore, low-threshold mechanoreceptors associated with Aδ and C nerve fibers have been identified in hairy skin. The process of mechanotransduction requires the conversion of a mechanical stimulus into electrical signals (action potentials) through the activation of mechanosensible ion channels present both in the axon and the periaxonal cells of sensory corpuscles (i.e., Schwann-, endoneurial- and perineurial-related cells). Most of those putative ion channels belong to the degenerin/epithelial sodium channel (especially the family of acid-sensing ion channels), the transient receptor potential channel superfamilies, and the Piezo family. This review updates the current data about the occurrence and distribution of putative mechanosensitive ion channels in cutaneous mechanoreceptors including primary sensory neurons and sensory corpuscles.
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10
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The evolution and multi-molecular properties of NF1 cutaneous neurofibromas originating from C-fiber sensory endings and terminal Schwann cells at normal sites of sensory terminations in the skin. PLoS One 2019; 14:e0216527. [PMID: 31107888 PMCID: PMC6527217 DOI: 10.1371/journal.pone.0216527] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 04/24/2019] [Indexed: 12/30/2022] Open
Abstract
In addition to large plexiform neurofibromas (pNF), NF1 patients are frequently disfigured by cutaneous neurofibromas (cNF) and are often afflicted with chronic pain and itch even from seemingly normal skin areas. Both pNFs and cNF consist primarily of benign hyperproliferating nonmyelinating Schwann cells (nSC). While pNF clearly arise within deep nerves and plexuses, the role of cutaneous innervation in the origin of cNF and in chronic itch and pain is unknown. First, we conducted a comprehensive, multi-molecular, immunofluorescence (IF) analyses on 3mm punch biopsies from three separate locations in normal appearing, cNF-free skin in 19 NF1 patients and skin of 16 normal subjects. At least one biopsy in 17 NF1 patients had previously undescribed micro-lesions consisting of a small, dense cluster of nonpeptidergic C-fiber endings and the affiliated nSC consistently adjoining adnexal structures—dermal papillae, hair follicles, sweat glands, sweat ducts, and arterioles—where C-fiber endings normally terminate. Similar micro-lesions were detected in hind paw skin of mice with conditionally-induced SC Nf1-/- mutations. Hypothesizing that these microlesions were pre-cNF origins of cNF, we subsequently analyzed numerous overt, small cNF (s-cNF, 3–6 mm) and discovered that each had an adnexal structure at the epicenter of vastly increased nonpeptidergic C-fiber terminals, accompanied by excessive nSC. The IF and functional genomics assays indicated that neurturin (NTRN) and artemin (ARTN) signaling through cRET kinase and GFRα2 and GFRα3 co-receptors on the aberrant C-fiber endings and nSC may mutually promote the onset of pre-cNF and their evolution to s-cNF. Moreover, TrpA1 and TrpV1 receptors may, respectively, mediate symptoms of chronic itch and pain. These newly discovered molecular characteristics might be targeted to suppress the development of cNF and to treat chronic itch and pain symptoms in NF1 patients.
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Jones A, Marshall CD. Does Vibrissal Innervation Patterns and Investment Predict Hydrodynamic Trail Following Behavior of Harbor Seals (
Phoca vitulina
)? Anat Rec (Hoboken) 2019; 302:1837-1845. [DOI: 10.1002/ar.24134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/07/2018] [Accepted: 12/09/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Aubree Jones
- Department of Marine BiologyTexas A&M University Galveston Campus Galveston, Texas
| | - Christopher D. Marshall
- Department of Marine BiologyTexas A&M University Galveston Campus Galveston, Texas
- Department of Wildlife and Fisheries SciencesTexas A&M University College Station Texas
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12
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A finite-element model of mechanosensation by a Pacinian corpuscle cluster in human skin. Biomech Model Mechanobiol 2018; 17:1053-1067. [DOI: 10.1007/s10237-018-1011-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 03/06/2018] [Indexed: 11/26/2022]
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13
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Abstract
The sensation of touch is mediated by mechanosensory neurons that are embedded in skin and relay signals from the periphery to the central nervous system. During embryogenesis, axons elongate from these neurons to make contact with the developing skin. Concurrently, the epithelium of skin transforms from a homogeneous tissue into a heterogeneous organ that is made up of distinct layers and microdomains. Throughout this process, each neuronal terminal must form connections with an appropriate skin region to serve its function. This Review presents current knowledge of the development of the sensory microdomains in mammalian skin and the mechanosensory neurons that innervate them.
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Affiliation(s)
- Blair A Jenkins
- Department of Physiology & Cellular Biophysics and Department of Dermatology, Columbia University in the City of New York, New York, NY 10032, USA
| | - Ellen A Lumpkin
- Department of Physiology & Cellular Biophysics and Department of Dermatology, Columbia University in the City of New York, New York, NY 10032, USA
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14
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Kamioka M, Sasaki M, Yamada K, Endo H, Oishi M, Yuhara K, Tomikawa S, Sugimoto M, Oshida T, Kondoh D, Kitamura N. Mobility of the forearm in the raccoon (Procyon lotor), raccoon dog (Nyctereutes procyonoides) and red panda (Ailurus fulgens). J Vet Med Sci 2017; 79:224-229. [PMID: 27840376 PMCID: PMC5289265 DOI: 10.1292/jvms.16-0241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ranges of pronation/supination of forearms in raccoons, raccoon dogs and red pandas were nondestructively examined. Three carcasses of each species were
used for CT analysis, and the left forearms were scanned with a CT scanner in two positions: maximal supination and maximal pronation. Scanning data were
reconstructed into three-dimensional images, cross-sectional images were extracted at the position that shows the largest area in the distal part of ulna, and
then, the centroids of each cross section of the radius and ulna were detected. CT images of two positions were superimposed, by overlapping the outlines of
each ulna, and then, the centroids were connected by lines to measure the angle of rotation, as an index of range of mobility. The measurements in each animal
were analyzed, using the Tukey–Kramer method. The average angle of rotation was largest in raccoons and smallest in raccoon dogs, and the difference was
significant. In the maximally pronated forearm of all species, the posture was almost equal to the usual grounding position with palms touching the ground.
Therefore, the present results demonstrate that the forearms of raccoons can supinate to a greater degree from the grounding position with palms on the ground,
as compared with those of raccoon dogs and red pandas.
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Affiliation(s)
- Minao Kamioka
- Laboratory of Veterinary Anatomy, Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
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15
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Olson W, Dong P, Fleming M, Luo W. The specification and wiring of mammalian cutaneous low-threshold mechanoreceptors. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:389-404. [PMID: 26992078 DOI: 10.1002/wdev.229] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/04/2016] [Accepted: 01/12/2016] [Indexed: 11/08/2022]
Abstract
The mammalian cutaneous low-threshold mechanoreceptors (LTMRs) are a diverse set of primary somatosensory neurons that function to sense external mechanical force. Generally, LTMRs are composed of Aβ-LTMRs, Aδ-LTMRs, and C-LTMRs, which have distinct molecular, physiological, anatomical, and functional features. The specification and wiring of each type of mammalian cutaneous LTMRs is established during development by the interplay of transcription factors with trophic factor signalling. In this review, we summarize the cohort of extrinsic and intrinsic factors generating the complex mammalian cutaneous LTMR circuits that mediate our tactile sensations and behaviors. For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- William Olson
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter Dong
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Fleming
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wenqin Luo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Sarko DK, Rice FL, Reep RL. Elaboration and Innervation of the Vibrissal System in the Rock Hyrax (Procavia capensis). BRAIN, BEHAVIOR AND EVOLUTION 2015; 85:170-88. [PMID: 26022696 PMCID: PMC4490970 DOI: 10.1159/000381415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/04/2015] [Indexed: 12/16/2022]
Abstract
Mammalian tactile hairs are commonly found on specific, restricted regions of the body, but Florida manatees represent a unique exception, exhibiting follicle-sinus complexes (FSCs, also known as vibrissae or tactile hairs) on their entire body. The orders Sirenia (including manatees and dugongs) and Hyracoidea (hyraxes) are thought to have diverged approximately 60 million years ago, yet hyraxes are among the closest relatives to sirenians. We investigated the possibility that hyraxes, like manatees, are tactile specialists with vibrissae that cover the entire postfacial body. Previous studies suggested that rock hyraxes possess postfacial vibrissae in addition to pelage hair, but this observation was not verified through histological examination. Using a detailed immunohistochemical analysis, we characterized the gross morphology, innervation and mechanoreceptors present in FSCs sampled from facial and postfacial vibrissae body regions to determine that the long postfacial hairs on the hyrax body are in fact true vibrissae. The types and relative densities of mechanoreceptors associated with each FSC also appeared to be relatively consistent between facial and postfacial FSCs. The presence of vibrissae covering the hyrax body presumably facilitates navigation in the dark caves and rocky crevices of the hyrax's environment where visual cues are limited, and may alert the animal to predatory or conspecific threats approaching the body. Furthermore, the presence of vibrissae on the postfacial body in both manatees and hyraxes indicates that this distribution may represent the ancestral condition for the supraorder Paenungulata.
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Affiliation(s)
- Diana K. Sarko
- Dept of Anatomy, Cell Biology & Physiology, Edward Via College of Osteopathic Medicine, 350 Howard Street, Spartanburg, SC 29303
| | - Frank L. Rice
- Integrated Tissue Dynamics, 7 University Place, Suite B236, Rensselaer, NY 12144
| | - Roger L. Reep
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610
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Rice FL, Albrecht PJ, Wymer JP, Black JA, Merkies IS, Faber CG, Waxman SG. Sodium channel Nav1.7 in vascular myocytes, endothelium, and innervating axons in human skin. Mol Pain 2015; 11:26. [PMID: 25957174 PMCID: PMC4447014 DOI: 10.1186/s12990-015-0024-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 04/24/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The skin is a morphologically complex organ that serves multiple complementary functions, including an important role in thermoregulation, which is mediated by a rich vasculature that is innervated by sympathetic and sensory endings. Two autosomal dominant disorders characterized by episodes of severe pain, inherited erythromelalgia (IEM) and paroxysmal extreme pain disorder (PEPD) have been directly linked to mutations that enhance the function of sodium channel Nav1.7. Pain attacks are accompanied by reddening of the skin in both disorders. Nav1.7 is known to be expressed at relatively high levels within both dorsal root ganglion (DRG) and sympathetic ganglion neurons, and mutations that enhance the activity of Nav1.7 have been shown to have profound effects on the excitability of both cell-types, suggesting that dysfunction of sympathetic and/or sensory fibers, which release vasoactive peptides at skin vasculature, may contribute to skin reddening in IEM and PEPD. RESULTS In the present study, we demonstrate that smooth muscle cells of cutaneous arterioles and arteriole-venule shunts (AVS) in the skin express sodium channel Nav1.7. Moreover, Nav1.7 is expressed by endothelial cells lining the arterioles and AVS and by sensory and sympathetic fibers innervating these vascular elements. CONCLUSIONS These observations suggest that the activity of mutant Nav1.7 channels in smooth muscle cells of skin vasculature and innervating sensory and sympathetic fibers contribute to the skin reddening and/or pain in IEM and PEPD.
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Affiliation(s)
- Frank L Rice
- Integrated Tissue Dynamics, LLC, Rensselaer, NY, 12144, USA.
| | - Phillip J Albrecht
- Integrated Tissue Dynamics, LLC, Rensselaer, NY, 12144, USA. .,Department of Neurology, Albany Medical College, Albany, NY, 12209, USA.
| | - James P Wymer
- Department of Neurology, Albany Medical College, Albany, NY, 12209, USA.
| | - Joel A Black
- Center for Neuroscience & Regeneration Research, Yale University School of Medicine, West Haven, CT, 06516, USA. .,Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, 06516, USA.
| | - Ingemar Sj Merkies
- Department of Neurology, Spaarne Hospital, Hoofddorp, the Netherlands. .,Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands.
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands.
| | - Stephen G Waxman
- Center for Neuroscience & Regeneration Research, Yale University School of Medicine, West Haven, CT, 06516, USA. .,Rehabilitation Research Center, VA Connecticut Healthcare System, West Haven, CT, 06516, USA.
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Fleming MS, Luo W. The anatomy, function, and development of mammalian Aβ low-threshold mechanoreceptors. ACTA ACUST UNITED AC 2013; 8. [PMID: 24376457 DOI: 10.1007/s11515-013-1271-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Touch sensation is critical for our social and environmental interactions. In mammals, most discriminative light touch sensation is mediated by the Aβ low-threshold mechanoreceptors. Cell bodies of Aβ low-threshold mechanoreceptors are located in the dorsal root ganglia and trigeminal ganglia, which extend a central projection innervating the spinal cord and brain stem and a peripheral projection innervating the specialized mechanosensory end organs. These specialized mechanosensory end organs include Meissner's corpuscles, Pacinian corpuscles, lanceolate endings, Merkel cells, and Ruffini corpuscles. The morphologies and physiological properties of these mechanosensory end organs and their innervating neurons have been investigated for over a century. In addition, recent advances in mouse genetics have enabled the identification of molecular mechanisms underlying the development of Aβ low-threshold mechanoreceptors, which highlight the crucial roles of neurotrophic factor signaling and transcription factor activity in this process. Here, we will review the anatomy, physiological properties, and development of mammalian low-threshold Aβ mechanoreceptors.
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Affiliation(s)
- Michael S Fleming
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Wenqin Luo
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
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Albrecht PJ, Hou Q, Argoff CE, Storey JR, Wymer JP, Rice FL. Excessive peptidergic sensory innervation of cutaneous arteriole-venule shunts (AVS) in the palmar glabrous skin of fibromyalgia patients: implications for widespread deep tissue pain and fatigue. PAIN MEDICINE 2013; 14:895-915. [PMID: 23691965 DOI: 10.1111/pme.12139] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To determine if peripheral neuropathology exists among the innervation of cutaneous arterioles and arteriole-venule shunts (AVS) in fibromyalgia (FM) patients. SETTING Cutaneous arterioles and AVS receive a convergence of vasoconstrictive sympathetic innervation, and vasodilatory small-fiber sensory innervation. Given our previous findings of peripheral pathologies in chronic pain conditions, we hypothesized that this vascular location may be a potential site of pathology and/or serotonergic and norepinephrine reuptake inhibitors (SNRI) drug action. SUBJECTS Twenty-four female FM patients and nine female healthy control subjects were enrolled for study, with 14 additional female control subjects included from previous studies. AVS were identified in hypothenar skin biopsies from 18/24 FM patient and 14/23 control subjects. METHODS Multimolecular immunocytochemistry to assess different types of cutaneous innervation in 3 mm skin biopsies from glabrous hypothenar and trapezius regions. RESULTS AVS had significantly increased innervation among FM patients. The excessive innervation consisted of a greater proportion of vasodilatory sensory fibers, compared with vasoconstrictive sympathetic fibers. In contrast, sensory and sympathetic innervation to arterioles remained normal. Importantly, the sensory fibers express α2C receptors, indicating that the sympathetic innervation exerts an inhibitory modulation of sensory activity. CONCLUSIONS The excessive sensory innervation to the glabrous skin AVS is a likely source of severe pain and tenderness in the hands of FM patients. Importantly, glabrous AVS regulate blood flow to the skin in humans for thermoregulation and to other tissues such as skeletal muscle during periods of increased metabolic demand. Therefore, blood flow dysregulation as a result of excessive innervation to AVS would likely contribute to the widespread deep pain and fatigue of FM. SNRI compounds may provide partial therapeutic benefit by enhancing the impact of sympathetically mediated inhibitory modulation of the excess sensory innervation.
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Absence of pain with hyperhidrosis: A new syndrome where vascular afferents may mediate cutaneous sensation. Pain 2009; 147:287-98. [DOI: 10.1016/j.pain.2009.09.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 09/01/2009] [Accepted: 09/09/2009] [Indexed: 12/22/2022]
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21
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GüÇlü B, Mahoney GK, Pawson LJ, Pack AK, Smith RL, Bolanowski SJ. Localization of Merkel cells in the monkey skin: An anatomical model. Somatosens Mot Res 2009; 25:123-38. [DOI: 10.1080/08990220802131234] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Burak GüÇlü
- Institute for Sensory Research, Syracuse, NY, USA
- Biomedical Engineering Institute, Boğaziçi University, Istanbul, Turkey
| | - Greer K. Mahoney
- Institute for Sensory Research, Syracuse, NY, USA
- Department of Biomedical & Chemical Engineering, Syracuse University, Syracuse, NY, USA
| | - Lorraine J. Pawson
- Institute for Sensory Research, Syracuse, NY, USA
- Department of Biomedical & Chemical Engineering, Syracuse University, Syracuse, NY, USA
| | - Adam K. Pack
- Institute for Sensory Research, Syracuse, NY, USA
- Department of Biology, Utica College, Utica, NY, USA
| | - Robert L. Smith
- Institute for Sensory Research, Syracuse, NY, USA
- Department of Biomedical & Chemical Engineering, Syracuse University, Syracuse, NY, USA
| | - Stanley J. Bolanowski
- Institute for Sensory Research, Syracuse, NY, USA
- Department of Biomedical & Chemical Engineering, Syracuse University, Syracuse, NY, USA
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22
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Taylor AM, Peleshok JC, Ribeiro-da-Silva A. Distribution of P2X3-immunoreactive fibers in hairy and glabrous skin of the rat. J Comp Neurol 2009; 514:555-66. [DOI: 10.1002/cne.22048] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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23
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Ebenezer GJ, Laast VA, Dearman B, Hauer P, Tarwater PM, Adams RJ, Zink MC, McArthur JC, Mankowski JL. Altered cutaneous nerve regeneration in a simian immunodeficiency virus / macaque intracutaneous axotomy model. J Comp Neurol 2009; 514:272-83. [PMID: 19296476 DOI: 10.1002/cne.22019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
To characterize the regenerative pattern of cutaneous nerves in simian immunodeficiency virus (SIV)-infected and uninfected macaques, excisional axotomies were performed in nonglabrous skin at 14-day intervals. Samples were examined after immunostaining for the pan-axonal marker PGP 9.5 and the Schwann cell marker p75 nerve growth factor receptor. Collateral sprouting of axons from adjacent uninjured superficial dermal nerve bundles was the initial response to axotomy. Both horizontal collateral sprouts and dense vertical regeneration of axons from the deeper dermis led to complete, rapid reinnervation of the epidermis at the axotomy site. In contrast to the slower, incomplete reinnervation previously noted in humans after this technique, in both SIV-infected and uninfected macaques epidermal reinnervation was rapid and completed by 56 days postaxotomy. p75 was densely expressed on the Schwann cells of uninjured nerve bundles along the excision line and on epidermal Schwann cell processes. In both SIV-infected and uninfected macaques, Schwann cell process density was highest at the earliest timepoints postaxotomy and then declined at a similar rate. However, SIV-infection delayed epidermal nerve fiber regeneration and remodeling of new sprouts at every timepoint postaxotomy, and SIV-infected animals consistently had lower mean epidermal Schwann cell densities, suggesting that Schwann cell guidance and support of epidermal nerve fiber regeneration may account for altered nerve regeneration. The relatively rapid regeneration time and the completeness of epidermal reinnervation in this macaque model provides a useful platform for assessing the efficacy of neurotrophic or regenerative drugs for sensory neuropathies including those caused by HIV, diabetes mellitus, medications, and toxins.
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Affiliation(s)
- Gigi J Ebenezer
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21287-7609, USA
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Yasui T, Tsukise A, Schnapper A, Meyer W. Ultrastructural and carbohydrate histochemical study of the Vater-Pacini corpuscles in the digital pads of the North American raccoon (Procyon lotor), with special regard to basic function. EUR J WILDLIFE RES 2007. [DOI: 10.1007/s10344-007-0142-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Bouley DM, Alarcón CN, Hildebrandt T, O'Connell-Rodwell CE. The distribution, density and three-dimensional histomorphology of Pacinian corpuscles in the foot of the Asian elephant (Elephas maximus) and their potential role in seismic communication. J Anat 2007; 211:428-35. [PMID: 17711421 PMCID: PMC2375831 DOI: 10.1111/j.1469-7580.2007.00792.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Both Asian (Elephas maximus) and African (Loxodonta africana) elephants produce low-frequency, high-amplitude rumbles that travel well through the ground as seismic waves, and field studies have shown that elephants may utilize these seismic signals as one form of communication. Unique elephant postures observed in field studies suggest that the elephants use their feet to 'listen' to these seismic signals, but the exact sensory mechanisms used by the elephant have never been characterized. The distribution, morphology and tissue density of Pacinian corpuscles, specialized mechanoreceptors, were studied in a forefoot and hindfoot of Asian elephants. Pacinian corpuscles were located in the dermis and distal digital cushion and were most densely localized to the anterior, posterior, medial and lateral region of each foot, with the highest numbers in the anterior region of the forefoot (52.19%) and the posterior region of the hindfoot (47.09%). Pacinian corpuscles were encapsulated, had a typical lamellar structure and were most often observed in large clusters. Three-dimensional reconstruction through serial sections of the dermis revealed that individual Pacinian corpuscles may be part of a cluster. By studying the distribution and density of these mechanoreceptors, we propose that Pacinian corpuscles are one possible anatomic mechanism used by elephants to detect seismic waves.
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Affiliation(s)
- D M Bouley
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, CA, USA.
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26
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Sarko DK, Reep RL, Mazurkiewicz JE, Rice FL. Adaptations in the structure and innervation of follicle-sinus complexes to an aquatic environment as seen in the Florida manatee (Trichechus manatus latirostris). J Comp Neurol 2007; 504:217-37. [PMID: 17640045 DOI: 10.1002/cne.21446] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Florida manatees are large-bodied aquatic herbivores that use large tactile vibrissae for several purposes. Facial vibrissae are used to forage in a turbid water environment, and the largest perioral vibrissae can also grasp and manipulate objects. Other vibrissae distributed over the entire postfacial body appear to function as a lateral line system. All manatee vibrissae emanate from densely innervated follicle-sinus complexes (FSCs) like those in other mammals, although proportionately larger commensurate with the caliber of the vibrissae. As revealed by immunofluorescence, all manatee FSCs have many types of C, Adelta and Abeta innervation including Merkel, club, and longitudinal lanceolate endings at the level of the ring sinus, but they lack other types such as reticular and spiny endings at the level of the cavernous sinus. As in non-whisking terrestrial species, the inner conical bodies of facial FSCs are well innervated but lack Abeta-fiber terminals. Importantly, manatee FSCs have two unique types of Abeta-fiber endings. First, all of the FSCs have exceptionally large-caliber axons that branch to terminate as novel, gigantic spindle-like endings located at the upper ring sinus. Second, facial FSCs have smaller caliber Abeta fibers that terminate in the trabeculae of the cavernous sinus as an ending that resembles a Golgi tendon organ. In addition, the largest perioral vibrissae, which are used for grasping, have exceptionally well-developed medullary cores that have a structure and dense small-fiber innervation resembling that of tooth pulp. Other features of the epidermis and upper dermis structure and innervation differ from that seen in terrestrial mammals.
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Affiliation(s)
- Diana K Sarko
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA.
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27
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Cannon KE, Chazot PL, Hann V, Shenton F, Hough LB, Rice FL. Immunohistochemical localization of histamine H3 receptors in rodent skin, dorsal root ganglia, superior cervical ganglia, and spinal cord: potential antinociceptive targets. Pain 2006; 129:76-92. [PMID: 17134835 PMCID: PMC1939926 DOI: 10.1016/j.pain.2006.09.039] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 08/04/2006] [Accepted: 09/28/2006] [Indexed: 01/01/2023]
Abstract
Activation of histamine H3 receptors (H3Rs) reduces inflammation and nociception, but the existence of H3Rs on peripheral innervation has never been demonstrated. Here we use antibodies to locate H3Rs in whisker pads, hairy and glabrous hind paw skin, dorsal root ganglia (DRGs), and spinal cords of rats, wild type mice, and H3R knockout (H3KO) mice. Although H3Rs have been hypothesized to be on C and sympathetic fibers, H3R-like immunoreactivity (H3R-LI) was only detected on presumptive periarterial A delta fibers and on A beta fibers that terminated in Meissner's corpuscles and as lanceolate endings around hair follicles. The H3R-positive periarterial fibers were thin-caliber and coexpressed immunoreactivity for calcitonin gene-related peptide (CGRP), substance P, acid sensing ion channel 3, and 200 kDa neurofilament protein (NF). H3R-LI was also detected on epidermal keratinocytes and Merkel cells, but not on Merkel endings, C fibers, any other A delta fibers, or sympathetic fibers. In DRGs, H3R-LI was preponderantly on medium to large neurons coexpressing NF-LI and mostly CGRP-LI. In dorsal horn, CGRP-positive fibers with and without H3R-LI ramified extensively in lamina II; many of the former formed a plexus in lamina V. Low levels of H3R-LI were also present on A beta fibers penetrating superficial and into deeper laminae. The distribution of H3R-LI was similar in rats and wild type mice, but was eliminated or strongly reduced in A delta fibers and A beta fibers, respectively, in H3KO mice. Taken with recently published behavioral results, the present findings suggest that periarterial, peptidergic, H3R-containing A delta fibers may be sources of high threshold mechanical nociception.
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Affiliation(s)
- Keri E. Cannon
- Center for Neuropharmacology and Neuroscience, Albany Medical College MC-136, Albany, NY, USA
| | - Paul L. Chazot
- School of Biological and Biomedical Sciences, University of Durham, Durham, UK
| | - Victoria Hann
- School of Biological and Biomedical Sciences, University of Durham, Durham, UK
| | - Fiona Shenton
- School of Biological and Biomedical Sciences, University of Durham, Durham, UK
| | - Lindsay B. Hough
- Center for Neuropharmacology and Neuroscience, Albany Medical College MC-136, Albany, NY, USA
| | - Frank L. Rice
- Center for Neuropharmacology and Neuroscience, Albany Medical College MC-136, Albany, NY, USA
- *Corresponding author: Dr. Frank L. Rice, Center for Neuropharmacology and Neuroscience, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, E-mail:
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Weir KA, Lunam CA. Immunohistochemical study of cutaneous nerves in the emu. Cell Tissue Res 2006; 326:697-705. [PMID: 16807724 DOI: 10.1007/s00441-006-0245-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 05/11/2006] [Indexed: 10/24/2022]
Abstract
The distribution and chemical content of cutaneous nerves in 3- to 13-day-old emu chicks (Dromaius novaehollandiae) were examined by using double-labelling immunohistochemistry. Seven different subpopulations of cutaneous nerves were identified based on their neurochemistry. No intraepidermal nerve fibres were found. However, axons were located within the dermis and were often associated with blood vessels, pennamotor muscles and feather follicles or innervated Herbst corpuscles. Both similarities and differences exist between subpopulations of cutaneous nerves in the emu and volant birds. As in volant birds, a subpopulation of cutaneous axons innervates the superficial skin layers and contains immunoreactivity to both substance P and calcitonin gene-related peptide (CGRP). This suggests that the neuropeptide content of these presumptive free nerve endings is conserved throughout the evolution of birds. In contrast, Herbst corpuscles in the emu are innervated by axons that contain immunoreactivity for CGRP or neuropeptide Y (NPY) but that lack the calbindin D-28k immunoreactivity found in fibres innervating Herbst corpuscles of volant birds. Herbst corpuscles therefore may have a different chemical content in a flightless species from that in volant birds.
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Affiliation(s)
- Kristy A Weir
- Department of Anatomy and Histology and Centre for Neuroscience, Flinders University, G.P.O. Box 2100, Adelaide, South Australia 5001, Australia
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29
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Albrecht PJ, Hines S, Eisenberg E, Pud D, Finlay DR, Connolly KM, Paré M, Davar G, Rice FL. Pathologic alterations of cutaneous innervation and vasculature in affected limbs from patients with complex regional pain syndrome. Pain 2006; 120:244-266. [PMID: 16427199 DOI: 10.1016/j.pain.2005.10.035] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 09/28/2005] [Accepted: 10/13/2005] [Indexed: 01/09/2023]
Abstract
Complex regional pain syndromes (CRPS, type I and type II) are devastating conditions that can occur following soft tissue (CRPS type I) or nerve (CRPS type II) injury. CRPS type I, also known as reflex sympathetic dystrophy, presents in patients lacking a well-defined nerve lesion, and has been questioned as to whether or not it is a true neuropathic condition with an organic basis. As described here, glabrous and hairy skin samples from the amputated upper and lower extremity from two CRPS type I diagnosed patients were processed for double-label immunofluorescence using a battery of antibodies directed against neural-related proteins and mediators of nociceptive sensory function. In CRPS affected skin, several neuropathologic alterations were detected, including: (1) the presence of numerous abnormal thin caliber NF-positive/MBP-negative axons innervating hair follicles; (2) a decrease in epidermal, sweat gland, and vascular innervation; (3) a loss of CGRP expression on remaining innervation to vasculature and sweat glands; (4) an inappropriate expression of NPY on innervation to superficial arterioles and sweat glands; and (5) a loss of vascular endothelial integrity and extraordinary vascular hypertrophy. The results are evidence of widespread cutaneous neuropathologic changes. Importantly, in these CRPS type I patients, the myriad of clinical symptoms observed had detectable neuropathologic correlates.
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Affiliation(s)
- Phillip J Albrecht
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY, USA Medical School Program, Albany Medical College, Albany, NY, USA Pain Relief Unit, Rambam Medical Center, Haifa, Israel Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel Faculty of Social Welfare and Health Studies, University of Haifa, Haifa, Israel Department of Dermatology, University of California, San Francisco, CA, USA Early Development, Medical Sciences, Amgen, Inc., Thousand Oaks, CA, USA
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Oaklander AL, Siegel SM. Cutaneous innervation: Form and function. J Am Acad Dermatol 2005; 53:1027-37. [PMID: 16310064 DOI: 10.1016/j.jaad.2005.08.049] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 08/23/2005] [Accepted: 08/28/2005] [Indexed: 12/11/2022]
Abstract
It is useful for dermatologists to know about the innervation of the skin because dysfunction of cutaneous neurons can cause symptoms--such as itching, pain, and paresthesias--that are evaluated by dermatologists. We review the innervation of the skin and update readers about recent neuroscientific discoveries.
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Affiliation(s)
- Anne Louise Oaklander
- Department of Anesthesiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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31
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Grelik C, Allard S, Ribeiro-da-Silva A. Changes in nociceptive sensory innervation in the epidermis of the rat lower lip skin in a model of neuropathic pain. Neurosci Lett 2005; 389:140-5. [PMID: 16139429 DOI: 10.1016/j.neulet.2005.07.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 06/18/2005] [Accepted: 07/20/2005] [Indexed: 12/21/2022]
Abstract
The epidermis is innervated by fine nerve endings that are important in the perception of nociceptive stimuli. However, their role in neuropathic pain is controversial. In this paper, changes in the innervation patterns of epidermal sensory afferent fibres in the rat lower lip have been studied following bilateral chronic constriction injury (CCI) of the mental nerve-a purely sensory branch of the trigeminal nerve. Sections of the lower lip were processed for immunocytochemistry using antibodies against Protein Gene Product (PGP) 9.5 and Calcitonin Gene-Related Peptide (CGRP) to identify the non-peptidergic and the peptidergic populations of nociceptive small diameter primary sensory afferent fibres. Peptidergic fibres co-localised both markers and the non-peptidergic fibres only stained for PGP 9.5 and not for CGRP. We quantified the total fibre length per 6000 microm(2) in the epidermis at several time points following CCI. Our data indicate that both fibre populations were significantly decreased at 2 weeks post-CCI, followed by fibre re-growth at levels above those seen in sham-operated animals at 4 weeks; however, this increase was only statistically significant for the non-peptidergic population. At 8 weeks post-CCI, the fibre lengths of both populations did not differ significantly from shams. This transient hyper-innervation of the epidermis by one subpopulation of nociceptive fibres coincided with the occurrence of spontaneous pain or dysesthetic sensations which we detected in a previous study in the same animal model. Therefore, we speculate that this transient hyper-innervation of the epidermis following injury could play a role in nociception in these animals.
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Affiliation(s)
- C Grelik
- Department of Pharmacology and Therapeutics, 3655 Prom. Sir-William-Osler, Montreal, Que., Canada H3G 1Y6
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Nedelec B, Hou Q, Sohbi I, Choinière M, Beauregard G, Dykes RW. Sensory perception and neuroanatomical structures in normal and grafted skin of burn survivors. Burns 2005; 31:817-30. [PMID: 16199293 DOI: 10.1016/j.burns.2005.06.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Accepted: 06/10/2005] [Indexed: 11/22/2022]
Abstract
BACKGROUND This study compared the neural structures found in grafted skin of burn survivors with neural structures found in site-matched normal skin and correlated these structures with psychophysical measures of sensation. METHODS Fifteen skin-grafted male burn survivors (47.7+/-10.4 years old) with deep partial- or full-thickness thermal burn injuries covering an average of 11+/-5.6% of their total body surface and with normal skin at a matching, unburned, contralateral site were recruited into this study. Threshold determinations and magnitude estimations for touch, cold, warmth and heat-pain were performed at sites with grafted and normal skin, using Semmes-Weinstein monofilaments and the Medoc TSA 2001 thermal stimulator. Skin biopsies from both the grafted and normal sites were stained with antibodies for protein gene product 9.5 (PGP) and neurofilament 200 kDa. Nerve fibers in the epidermis and nerve fibers or bundles of nerve fibers in the superficial and deep dermis as well as innervated blood vessels, hair follicles and sweat glands were counted. RESULTS On average, the data were collected 43.1+/-10.4 months after grafting. When thresholds on grafted skin were compared to thresholds on normal skin, they showed elevated sensory thresholds [touch (p<0.003), cold (p<0.031), warmth (p<0.009)]. Magnitude estimates of touch, cold and warmth differed on the two sides with sensations elicited from grafts being smaller than those from normal skin. Heat-pain thresholds and heat-pain magnitude estimations were not statistically different on the two sites. By comparison to the normal side, and consistent with the attenuated sensory functions of the grafts, counts of neural structures showed a reduction in innervation density; PGP-immunoreactive nerve fibers/bundles were reduced in grafted epidermis (p<0.026) and superficial dermis (p<0.001). The numbers of sweat glands (p<0.006) and hair follicles (p<0.001) were also reduced. The number of innervated blood vessels did not differ significantly on the two sides. There were significant correlations between sensory thresholds and the neuroanatomical variables: thresholds of cold and touch were correlated with the number of sweat glands in both grafted and normal skin (r2=0.56 and 0.50, respectively; p<0.001), while warmth thresholds were significantly correlated with the number of innervated blood vessels in grafted skin (r2=0.62, p<0.001). Encapsulated mechanoreceptors were not encountered in this study of hairy skin. CONCLUSIONS Touch, cold and warmth thresholds and magnitude estimations do not return to normal levels after skin grafting in burn survivors. The elevation of thresholds and reduction of sensory intensity is accompanied by a general decrease in the density of nerve terminals. The lack, or numerical reduction, of sweat glands and innervated blood vessels was also indicative of diminished sensation on grafted skin.
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Affiliation(s)
- Bernadette Nedelec
- McGill University, Faculty of Medicine, School of Physical and Occupational Therapy, 3654 Promenade Sir William Osler, Montréal, Que., Canada H3G 1Y5.
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Kelly EJ, Terenghi G, Hazari A, Wiberg M. Nerve fibre and sensory end organ density in the epidermis and papillary dermis of the human hand. ACTA ACUST UNITED AC 2005; 58:774-9. [PMID: 16086989 DOI: 10.1016/j.bjps.2004.12.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Accepted: 12/09/2004] [Indexed: 11/28/2022]
Abstract
Quantification of sensory recovery after peripheral nerve surgery is difficult and no accurate techniques are available at present. Quantification of reinnervated skin has been used experimentally, and in some clinical studies, but the lack of knowledge about the normal sensory distribution has been a problem. The purpose of this study was, therefore, to map the density of sensory end organs, nerve fibres and free nerve endings in the glabrous skin of the human hand. Skin biopsies were taken from patients undergoing acute and elective hand surgery. Nerve fibres were stained in the epidermis and papillary dermis and quantified in five sites on the palm of the hand, using protein gene product 9.5 immunoreactivity-a panneuronal marker. The finger tip skin was found to have more than twice the nerve fibre density in the papillary dermis than the skin of the palm, and the number of Meissner corpuscles in the finger tip was also higher than in the palm. We found a reduction in innervation density with increasing age in the dermis, however, that was not the case for the epidermis. The innervation of the epidermis showed high interindividual variability and unlike the papillary dermis did not display any pattern of distribution in the hand.
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Affiliation(s)
- E J Kelly
- Department of Anatomy and Hand and Plastic Surgery, Umeå University, Umeå, Sweden
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Yasui T, Tsukise A, Meyer W. Localization of epidermal hyaluronan in the foot pads of the North American raccoon (Procyon lotor). ACTA ACUST UNITED AC 2005; 67:219-26. [PMID: 15570887 DOI: 10.1679/aohc.67.219] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The localization of the epidermal hyaluronan in the digital foot pads of the North American raccoon (Procyon lotor) was examined by light and electron microscopic histochemical methods. The thick epidermis contained five epidermal layers composed of typical keratinocytes. In the stratum basale and stratum spinosum, hyaluronic acid was clearly detectable at cytoplasmic processes, in close vicinity to the surface coat of the plasma membrane, and/or in the intercellular space between the basal and spinous cells. The results suggest that epidermal hyaluronan that fills the intercellular space may particularly control water maintenance in the epidermis of the raccoon digital pads to guarantee the optimal mechanoreceptive function of the very specific and sensitive sensoric subepidermal equipment in this mammalian species.
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Affiliation(s)
- Tadashi Yasui
- Department of Veterinary Anatomy, College of Bioresource Sciences, Nihon University, Fujisawa, Japan
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Yasui T, Tsukise A, Meyer W. Ultracytochemical Demonstration of Glycoproteins in the Eccrine Glands of the Digital Pads of the North American Raccoon (Procyon lotor). Anat Histol Embryol 2005; 34:56-60. [PMID: 15649229 DOI: 10.1111/j.1439-0264.2004.00577.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the eccrine glands of the digital pads of the North American raccoon (Procyon lotor), ultrastructural localization of glycoproteins with various saccharide residues was studied using preferably lectin cytochemical methods. Secretory granules observed in the dark cells exhibited glycoproteins with different terminal sugars (alpha-D-mannose, beta-D-galactose, beta-N-acetyl-D-glucosamine and sialic acid). The cytoplasm of the clear cells contained numerous glycogen particles. Several sugars were also detectable in the surface coat of the plasma membrane of the secretory cells. The results obtained could be helpful in understanding secretion production and cell related secretion functions of the eccrine glands of the raccoon digital foot pads.
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Affiliation(s)
- T Yasui
- Department of Veterinary Anatomy, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan
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Watson AHD. Synaptic interactions between the terminals of slow-adapting type II mechanoreceptor afferents and neurones expressing gamma-aminobutyric acid- and glycine-like immunoreactivity in the rat spinal cord. J Comp Neurol 2004; 471:168-79. [PMID: 14986310 DOI: 10.1002/cne.20043] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The object of this study was to analyse the synaptic interactions of slow-adapting type II (SAII) afferent terminals in laminae III-V of the rat spinal cord. The axons of SAII afferents were physiologically characterized by intracellular recording before injection with neurobiotin and preparation for electron microscopy. Axon terminals were serially sectioned and immunolabelled with antibodies against gamma-aminobutyric acid (GABA) or glycine by using a postembedding immunogold procedure. Computer-aided reconstruction was used to reveal the relative distribution of different types of synapses on terminal and en passant synaptic boutons. Eighty-nine percent of boutons received axoaxonic synaptic contacts, the mean number of contacts per bouton being 3.5. Fifty-nine percent of presynaptic axons were immunoreactive for both GABA and glycine and 45% for GABA alone. Most boutons (95%) made axodendritic contacts, and the mean number of dendrites contacted was 1.6. More than half of the postsynaptic dendrites were greater than 1 microm in diameter. Twenty-three percent were immunoreactive for glycine, and 71% were not immunoreactive for either antibody. Synaptic triads in which an axon presynaptic to the afferent was also in contact with a dendrite postsynaptic to the afferent were seen at 63% of boutons. These results are discussed in the light of similar studies of other low-threshold mechanoreceptive afferent terminals in the rat and cat and in the context of what is known of the sensory interneurones carrying information from slow- and rapid-adapting mechanoreceptors.
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Affiliation(s)
- Alan H D Watson
- School of Biosciences, Cardiff University, Cardiff CF10 3US, United Kingdom.
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Park TJ, Comer C, Carol A, Lu Y, Hong HS, Rice FL. Somatosensory organization and behavior in naked mole-rats: II. Peripheral structures, innervation, and selective lack of neuropeptides associated with thermoregulation and pain. J Comp Neurol 2003; 465:104-20. [PMID: 12926019 DOI: 10.1002/cne.10824] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
African naked mole-rats are subterranean rodents that have a robust orienting response to stimulation of unique vibrissa-like body hairs that are widely spaced over an otherwise hairless skin. To determine whether these large body hairs have a specialized organization similar to facial vibrissae, the structure and innervation of facial vibrissa follicles, body hair follicles, and intervening skin in naked mole-rats was compared with that in rats and a furred African mole-rat species (the common mole-rat). Immunofluorescence and lectin-binding analyses revealed that the body hair follicles in naked mole-rats were exceptionally large and well innervated, similar to guard hairs of furred species. However, these body vibrissae lacked the anatomic specializations and unique types of innervation affiliated with follicle sinus complexes of facial vibrissae. In contrast to the furred species, naked mole-rats had a paucity of Abeta-fiber Merkel endings at all peripheral locations. Naked mole-rats also were completely lacking in cutaneous C-fibers immunoreactive for substance P and calcitonin gene-related peptide. In contrast, the hairless skin of the naked mole-rats had an exceptional abundance of presumptive Adelta-fibers. The unusual features of the cutaneous innervation in naked mole-rats are presumably adaptations to their subterranean environment and that they are the only known poikilothermic mammal. The features of this mammalian model system provide unique opportunities to discriminate mechanisms related to tactile spatial orientation, vascular regulation, and nociception.
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Affiliation(s)
- Thomas J Park
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
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Paré M, Behets C, Cornu O. Paucity of presumptive ruffini corpuscles in the index finger pad of humans. J Comp Neurol 2003; 456:260-6. [PMID: 12528190 DOI: 10.1002/cne.10519] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Classically recognized as the cutaneous stretch receptors associated with the slowly adapting type II (SAII) primary afferents, Ruffini corpuscles have rarely been reported in the skin, despite numerous histologic investigations. Electrophysiological recordings of the primary afferents in humans suggest that SAII fibers represent approximately 15% of the myelinated mechanosensitive axons in the peripheral nerves innervating the volar surface of the hand. In the present study, an analysis of glabrous skin was conducted in human donors to assess the distribution of Ruffini and Ruffini-like corpuscles in the distal phalanx of the index finger. Only one presumptive Ruffini corpuscle was found in the skin processed for double immunofluorescence labeling with antibodies against protein gene product 9.5 and neurofilament 200-kDa subunit. Based on their relatively scattered distributions, we conclude that very few SAII primary afferents are likely to terminate as Ruffini corpuscles in human glabrous skin.
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Affiliation(s)
- Michel Paré
- Center for Neuropharmacology and Neuroscience, Albany Medical College, New York 12208, USA.
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Manger PR, Elston GN, Pettigrew JD. Multiple maps and activity-dependent representational plasticity in the anterior Wulst of the adult barn owl (Tyto alba). Eur J Neurosci 2002; 16:743-50. [PMID: 12270050 DOI: 10.1046/j.1460-9568.2002.02119.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present study we addressed the issue of somatosensory representation and plasticity in a nonmammalian species, the barn owl. Multiunit mapping techniques were used to examine the representation of the specialized receptor surface of the claw in the anterior Wulst. We found dual somatotopic mirror image representations of the skin surface of the contralateral claw. In addition, we examined both representations 2 weeks after denervation of the distal skin surface of a single digit. In both representations, the denervated digital representation became responsive to stimulation of the adjacent, mutually functional, digit. The mutability and multiple representations indicates that the Wulst provides the owl with sensory processing capabilities analogous to those in mammals.
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Affiliation(s)
- Paul R Manger
- Vision, Touch and Hearing Research Centre, Department of Physiology and Pharmacology, The University of Queensland, Brisbane, 4072, Australia.
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Petersen KL, Rice FL, Suess F, Berro M, Rowbotham MC. Relief of post-herpetic neuralgia by surgical removal of painful skin. Pain 2002; 98:119-26. [PMID: 12098623 DOI: 10.1016/s0304-3959(02)00029-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a case of longstanding PHN treated by skin excision of the area of greatest pain (11.3 x 26.0 cm(2)). The operation reduced pain, eliminated tactile allodynia, and facilitated greatly reduced medication use over a 1-year follow-up period. Fourteen punch biopsies and 10 strips of skin (each 10 mm long) from the excised painful PHN skin were qualitatively assessed by double-label immunofluorescence using antibodies against protein-gene-product 9.5 (PGP9.5), 200 kDa neurofilament protein (NF), calcitonin gene-related peptide (CGRP) and vanilloid receptor-1 (VR-1). Compared with a punch biopsy from mirror image skin, the pattern of cutaneous innervation in PHN skin was consistently and substantially different. The results may explain the anatomical basis of the capsaicin-response test and have implications for our understanding of clinical mechanisms underlying PHN pain.
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Affiliation(s)
- Karin L Petersen
- Department of Neurology, UCSF Pain Clinical Research Center, University of California-San Francisco, 1701 Divisadero Street, Suite 480, San Francisco, CA 94115, USA.
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Paré M, Smith AM, Rice FL. Distribution and terminal arborizations of cutaneous mechanoreceptors in the glabrous finger pads of the monkey. J Comp Neurol 2002; 445:347-59. [PMID: 11920712 DOI: 10.1002/cne.10196] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Recent electrophysiological studies demonstrated that neurons in the somatosensory cortex of monkeys respond to tangential forces applied to glabrous skin. To unravel the peripheral basis for this cortical response, we determined the distribution of presumptive low-threshold mechanoreceptors innervating the distal finger pads of monkeys. Endings were reconstructed in immunolabeled serial sections imaged by epifluorescence and confocal microscopy. Although classically implicated as cutaneous stretch receptors, no Ruffini corpuscles were found in the glabrous skin. Ruffini-like endings were only detected at the base of the finger nails. Pacinian corpuscles were sparsely distributed in the deep dermis. Meissner corpuscles (MCs) in dermal papillary ridges had a comparably high density in the thumb, index, and fifth fingers. Each MC was innervated by several large-caliber axons. Within the limits of our reconstructions, some of these axons terminated in only one MC, whereas others innervated several MCs. Merkel endings covered about 80% of the base of the intermediate epidermal ridges that form the pattern of fingerprints. In some cases, the distal tip of a Merkel-related axon gave rise to a several terminal branches that supplied endings to tightly circumscribed (30-70 microm) clusters of Merkel cells. In other cases, the nodes of axons gave rise to en passant branches that formed extended chains of endings among Merkel cells spread over territories up to 300 microm long. Based on their relatively diffuse distributions, the axons that innervate multiple MCs or the axons with en passant Merkel terminations seem most suited to transduce tangential forces.
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Affiliation(s)
- Michel Paré
- Département de Physiologie, Université de Montréal, Montréal, Canada H3C 3J7
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The Meissner corpuscle revised: a multiafferented mechanoreceptor with nociceptor immunochemical properties. J Neurosci 2001. [PMID: 11549734 DOI: 10.1523/jneurosci.21-18-07236.2001] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Meissner corpuscles (MCs) in the glabrous skin of monkey digits have at least three types of innervation as revealed by immunofluorescence. The previously well known Aalphabeta-fiber terminals are closely intertwined with endings from peptidergic C-fibers. These intertwined endings are segregated into zones that alternate with zones containing a third type of ending supplied by nonpeptidergic C-fibers. Although MCs are widely regarded as low-threshold mechanoreceptors, all three types of innervation express immunochemical properties associated with nociception. The peptidergic C-fiber endings have readily detectable levels of immunoreactivity (IR) for calcitonin gene-related peptide (CGRP) and substance P (SP). The Aalphabeta endings have relatively lower levels of IR for CGRP and SP as well as the SP neurokinin 1 receptor and vanilloid-like receptor 1. Both the Aalphabeta and peptidergic C-fiber endings were also labeled with antibodies for different combinations of adrenergic, opioid, and purinergic receptors. The nonpeptidergic C-fiber endings express IR for vanilloid receptor 1, which has also been implicated in nociception. Thus, MCs are multiafferented receptor organs that may have nociceptive capabilities in addition to being low-threshold mechanoreceptors.
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Dick SH, French AS, Rasmusson DD. Postsynaptic dorsal column and cuneate neurons in raccoon: comparison of response properties and cross-correlation analysis. Brain Res 2001; 914:134-48. [PMID: 11578606 DOI: 10.1016/s0006-8993(01)02787-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The responses of 111 postsynaptic dorsal column (PSDC) neurons in the cervical spinal cord and 51 cuneate neurons with receptive fields on the glabrous skin of the forepaw were studied in anesthetized raccoons using extracellular recording techniques. The PSDC neurons had larger receptive fields than the cuneate neurons, but in both groups the fields never extended onto hairy skin. PSDC and cuneate neurons had approximately the same mean latency to electrical stimulation of the receptive field, but PSDC neurons had significantly lower thresholds. The majority of both PSDC and cuneate neurons also responded to electrical stimulation of an adjacent digit, even though they did not respond to mechanical stimulation of that digit. Cross-correlation analysis of the activity of 51 pairs of PSDC and cuneate neurons recorded simultaneously revealed a significant interaction in 26 pairs during spontaneous activity. In 20 of these neuron pairs, the probability that the cuneate neuron would fire was greater after the PSDC neuron had fired (suggesting a spinocuneate interaction), five pairs showed an interaction in the opposite (cuneospinal) direction, and one pair had a significant inhibitory interaction. These interactions occurred more often when the receptive fields of the two neurons were overlapping than when their fields were on adjacent digits. Frequency response analysis revealed greater coherence for those pairs showing a spinocuneate interaction than for those with a cuneospinal interaction. These results support the hypothesis that the PSDC system exerts a tonic facilitatory effect on cuneate neurons and that there may be some somatotopic organization to the interactions. However, the similar response latencies of the two groups of neurons makes it unlikely that PSDC neurons could contribute to the rapid initial processing of cutaneous information by the cuneate nucleus.
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Affiliation(s)
- S H Dick
- Department of Physiology & Biophysics, Dalhousie University, Nova Scotia, B3H 4H7, Halifax, Canada
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Abstract
This review summarizes recent developments in the context of the neurochemical classification of nociceptors and explores the relationships between functionally and neurochemically defined subgroups. Although the complete picture is not yet available, several lines of intriguing evidence suggest that despite the complexity and diversity of nociceptor properties, a relatively "simple" neurochemical classification fits well with several recently identified molecular characteristics.
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Affiliation(s)
- F J Alvarez
- Department of Anatomy, School of Medicine, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
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