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Royal Society Open Science Apr 2020Vibration sensing is ubiquitous among vertebrates, with the sensory end organ generally being a multilayered ellipsoidal structure. There is, however, a wide range of...
Vibration sensing is ubiquitous among vertebrates, with the sensory end organ generally being a multilayered ellipsoidal structure. There is, however, a wide range of sizes and structural arrangements across species. In this work, we applied our earlier computational model of the Pacinian corpuscle to predict the sensory response of different species to various stimulus frequencies, and based on the results, we identified the optimal frequency for vibration sensing and the bandwidth over which frequencies should be most detectable. We found that although the size and layering of the corpuscles were very different, almost all of the 19 species studied showed very similar sensitivity ranges. The human and goose were the notable exceptions, with their corpuscle tuned to higher frequencies (130-170 versus 40-50 Hz). We observed no correlation between animal size and any measure of corpuscle geometry in our model. Based on the results generated by our computational model, we hypothesize that lamellar corpuscles across different species may use different sizes and structures to achieve similar frequency detection bands.
PubMed: 32431862
DOI: 10.1098/rsos.191439 -
Skin Appendage Disorders Mar 2020This article gives an account of the commonest causes of nail pain. The acronyms GIFTED KID and FOMITE will help aid doctors in a busy clinical setting to remember the... (Review)
Review
This article gives an account of the commonest causes of nail pain. The acronyms GIFTED KID and FOMITE will help aid doctors in a busy clinical setting to remember the main causes of onychalgia, respectively, on the fingers and toes. It includes a brief overview of the clinical characteristics and focuses on the type of pain for each condition as well as the mechanisms that cause it.
PubMed: 32258050
DOI: 10.1159/000504347 -
Scientific Reports Mar 2020The function of the external ear canal in cetaceans is still under debate and its morphology is largely unknown. Immunohistochemical (IHC) analyses using antibodies...
The function of the external ear canal in cetaceans is still under debate and its morphology is largely unknown. Immunohistochemical (IHC) analyses using antibodies specific for nervous tissue (anti-S100, anti-NSE, anti-NF, and anti-PGP 9.5), together with transmission electron microscopy (TEM) and various histological techniques, were carried out to investigate the peripheral nervous system of the ear canals of several species of toothed whales and terrestrial Cetartiodactyla. This study highlights the innervation of the ear canal with the presence of lamellar corpuscles over its entire course, and their absence in all studied terrestrial mammals. Each corpuscle consisted of a central axon, surrounded by lamellae of Schwann receptor cells, surrounded by a thin cellular layer, as shown by IHC and TEM. These findings indicate that the corpuscles are mechanoreceptors that resemble the inner core of Pacinian corpuscles without capsule or outer core, and were labelled as simple lamellar corpuscles. They form part of a sensory system that may represent a unique phylogenetic feature of cetaceans, and an evolutionary adaptation to life in the marine environment. Although the exact function of the ear canal is not fully clear, we provide essential knowledge and a preliminary hypothetical deviation on its function as a unique sensory organ.
Topics: Animals; Axons; Ear Canal; Immunohistochemistry; Male; Microscopy, Electron, Transmission; Pacinian Corpuscles; Peripheral Nervous System; Phylogeny
PubMed: 32144309
DOI: 10.1038/s41598-020-61170-4 -
Case Reports in Plastic Surgery & Hand... 2019Pacinian corpuscle pathology is a rare clinical entity and an uncommonly reported cause of digital pain. While many prior reports implicate hand trauma, we describe a...
Pacinian corpuscle pathology is a rare clinical entity and an uncommonly reported cause of digital pain. While many prior reports implicate hand trauma, we describe a case of Pacinian hyperplasia found in a patient with Raynaud's phenomenon and propose a potential mechanism of disease.
PubMed: 32002464
DOI: 10.1080/23320885.2019.1698958 -
Anatomical Record (Hoboken, N.J. : 2007) Aug 2020Heparan sulfate proteoglycans are pericellular/cell surface molecules involved in somatosensory axon guidance in the peripheral nervous system. However, the distribution...
Heparan sulfate proteoglycans are pericellular/cell surface molecules involved in somatosensory axon guidance in the peripheral nervous system. However, the distribution of heparan sulfate proteoglycans in the extracellular matrix of human cutaneous sensory corpuscles is unknown. Immunohistochemistry and immunofluorescence assays were performed to define the localization of heparan sulfate proteoglycans in human cutaneous Meissner's and Pacinian corpuscles using two anti-heparan sulfate antibodies together with anti-S100 protein, anti-PGP9.5, anti-CD34 (to immunolabel basement membranes, Schwann cells, axon and the intermediate endoneurial layer of Pacinian corpuscles, respectively), anti-Type IV collagen, and anti-chondroitin sulfate antibodies. Heparan sulfate proteoglycans were colocalized with Type IV collagen in Meissner's corpuscles and were located in the outer core lamellae and capsule, but not in the inner core or the intermediate layer, in Pacinian corpuscles. Chondroitin sulfate was observed in the intermediate layer of Pacinian corpuscles but was never colocalized with heparan sulfate proteoglycans. The present results strongly suggest that heparan sulfate proteoglycans are associated with the basement membranes of the lamellar cells in Meissner's corpuscles and with the complex outer core capsule in Pacinian corpuscles. The functional significance of these results, if any, remains to be elucidated.
Topics: Adult; Collagen Type IV; Female; Heparitin Sulfate; Humans; Male; Mechanoreceptors; Middle Aged; Pacinian Corpuscles; S100 Proteins; Skin; Young Adult
PubMed: 31815364
DOI: 10.1002/ar.24328 -
Journal of Anatomy Feb 2020The palmaris brevis muscle contains numerous muscle spindles to control changes of the muscle length but is devoid of tendon-associated neuronal elements (e.g. Golgi...
The palmaris brevis muscle contains numerous muscle spindles to control changes of the muscle length but is devoid of tendon-associated neuronal elements (e.g. Golgi tendon organs or Ruffini-like corpuscles) controlling changes in muscle strength. Pacinian bodies, frequently seen in the palm of the hand, show no direct association to the muscle bundles. The observed innervation pattern of the palmaris brevis muscle points to a specific type of neuronal regulation, present in skeletal muscles with no skeletal connection.
Topics: Aged; Aged, 80 and over; Female; Hand; Humans; Male; Muscle Spindles; Muscle, Skeletal; Tendons
PubMed: 31696933
DOI: 10.1111/joa.13098 -
European Journal of Translational... Aug 2019The aim of this study was to characterize the microscopic structure and sensory nerve endings of the crural interosseous membrane (IM). 13 IMs from 7 cadavers were used...
The aim of this study was to characterize the microscopic structure and sensory nerve endings of the crural interosseous membrane (IM). 13 IMs from 7 cadavers were used to analyze the organization of the collagen fibers, IM's thickness, distribution of elastic fibers and nerve elements. The IM is mainly a two-layer collagen fascicle structure with the collagen fibers of adjacent layers orientated along different directions, forming angles of 30.5 +/- 1.7° at proximal and 26.6 +/- 2.1° at distal part (P>0.05). The percentage of elastic fibers between the two layers and inside the collagen fascicle layer is 10.1 +/- 0.5% and 2.2 +/- 0.1% (P<0.001). The IM's thickness at proximal, middle, and distal parts is 268.5 +/- 18.6μm; 293.2 +/- 12.5μm; 365.3 +/- 19.3 μm, respectively (Proximal vs Distal: P<0.001; Middle vs Distal: P<0.05). Nerve elements were present and located both inside and on the surface of the IM, whereas the mechanoreceptors are mainly located on the surface of the IM. Free nerve endings (33.3 +/- 5.0/cm) and Ruffini corpuscles (3.4 +/- 0.6/cm) were the predominant sensory elements, while Pacinian corpuscles (1.3 +/- 0.7/cm) were rarely found. The type of mechanoreceptors found suggests that the IM may play a role in proprioception.
PubMed: 31579480
DOI: 10.4081/ejtm.2019.8340 -
Nature Communications Sep 2019Biological cellular structures have inspired many scientific disciplines to design synthetic structures that can mimic their functions. Here, we closely emulate...
Biological cellular structures have inspired many scientific disciplines to design synthetic structures that can mimic their functions. Here, we closely emulate biological cellular structures in a rationally designed synthetic multicellular hybrid ion pump, composed of hydrogen-bonded [EMIM][TFSI] ion pairs on the surface of silica microstructures (artificial mechanoreceptor cells) embedded into thermoplastic polyurethane elastomeric matrix (artificial extracellular matrix), to fabricate ionic mechanoreceptor skins. Ionic mechanoreceptors engage in hydrogen bond-triggered reversible pumping of ions under external stimulus. Our ionic mechanoreceptor skin is ultrasensitive (48.1-5.77 kPa) over a wide spectrum of pressures (0-135 kPa) at an ultra-low voltage (1 mV) and demonstrates the ability to surpass pressure-sensing capabilities of various natural skin mechanoreceptors (i.e., Merkel cells, Meissner's corpuscles, Pacinian corpuscles). We demonstrate a wearable drone microcontroller by integrating our ionic skin sensor array and flexible printed circuit board, which can control directions and speed simultaneously and selectively in aerial drone flight.
Topics: Adult; Biomimetics; Biosensing Techniques; Electrochemistry; Humans; Hydrogen Bonding; Mechanoreceptors; Mechanotransduction, Cellular; Merkel Cells; Physical Stimulation; Polyurethanes; Pressure; Silica Gel; Skin; Skin Physiological Phenomena; Touch
PubMed: 31488820
DOI: 10.1038/s41467-019-11973-5 -
PLoS Biology Aug 2019Motion is an essential component of everyday tactile experience: most manual interactions involve relative movement between the skin and objects. Much of the research on...
Motion is an essential component of everyday tactile experience: most manual interactions involve relative movement between the skin and objects. Much of the research on the neural basis of tactile motion perception has focused on how direction is encoded, but less is known about how speed is. Perceived speed has been shown to be dependent on surface texture, but previous studies used only coarse textures, which span a restricted range of tangible spatial scales and provide a limited window into tactile coding. To fill this gap, we measured the ability of human observers to report the speed of natural textures-which span the range of tactile experience and engage all the known mechanisms of texture coding-scanned across the skin. In parallel experiments, we recorded the responses of single units in the nerve and in the somatosensory cortex of primates to the same textures scanned at different speeds. We found that the perception of speed is heavily influenced by texture: some textures are systematically perceived as moving faster than are others, and some textures provide a more informative signal about speed than do others. Similarly, the responses of neurons in the nerve and in cortex are strongly dependent on texture. In the nerve, although all fibers exhibit speed-dependent responses, the responses of Pacinian corpuscle-associated (PC) fibers are most strongly modulated by speed and can best account for human judgments. In cortex, approximately half of the neurons exhibit speed-dependent responses, and this subpopulation receives strong input from PC fibers. However, speed judgments seem to reflect an integration of speed-dependent and speed-independent responses such that the latter help to partially compensate for the strong texture dependence of the former.
Topics: Adult; Animals; Female; Humans; Macaca mulatta; Male; Motion Perception; Movement; Neurons; Skin; Somatosensory Cortex; Touch; Touch Perception; Young Adult
PubMed: 31454360
DOI: 10.1371/journal.pbio.3000431 -
ELife Aug 2019The established view is that vibrotactile stimuli evoke two qualitatively distinctive cutaneous sensations, flutter (frequencies < 60 Hz) and vibratory hum (frequencies...
The established view is that vibrotactile stimuli evoke two qualitatively distinctive cutaneous sensations, flutter (frequencies < 60 Hz) and vibratory hum (frequencies > 60 Hz), subserved by two distinct receptor types (Meissner's and Pacinian corpuscle, respectively), which may engage different neural processing pathways or channels and fulfil quite different biological roles. In psychological and physiological literature, those two systems have been labelled as Pacinian and non-Pacinian channels. However, we present evidence that low-frequency spike trains in Pacinian afferents can readily induce a vibratory percept with the same low frequency attributes as sinusoidal stimuli of the same frequency, thus demonstrating a universal frequency decoding system. We achieved this using brief low-amplitude pulsatile mechanical stimuli to selectively activate Pacinian afferents. This indicates that spiking pattern, regardless of receptor type, determines vibrotactile frequency perception. This mechanism may underlie the constancy of vibrotactile frequency perception across different skin regions innervated by distinct afferent types.
Topics: Action Potentials; Adult; Female; Healthy Volunteers; Humans; Male; Mechanoreceptors; Sensory Thresholds; Touch; Touch Perception; Young Adult
PubMed: 31383258
DOI: 10.7554/eLife.46510