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JPRAS Open Dec 2021Pacinian corpuscle hyperplasia is a pathological increase in the size (Pacinian hypertrophy) and/or density of mature Pacinian corpuscles. Although its aetiology and...
Pacinian corpuscle hyperplasia is a pathological increase in the size (Pacinian hypertrophy) and/or density of mature Pacinian corpuscles. Although its aetiology and pathogenesis remain unclear, surgery is the main treatment. Here, we report a rare case of Pacinian hypertrophy at the fingertip treated with surgical excision and reconstruction using a reverse digital artery flap. A 47-year-old man presented with injuries to his right little finger, which was wedged in a door while unloading a truck. His fingertip was amputated and stump plasty was performed. However, severe pain persisted at the fingertip for 5 months after the surgery. Therefore, the painful part of his fingertip was resected, and reconstruction was performed using a reverse digital artery flap 6 months after the injury. Haematoxylin and eosin staining of the resected specimen revealed scar tissue with foreign body reaction and mild Pacinian hypertrophy. One year has passed since the injury, and the pain has completely disappeared. The patient regained complete range of motion in his little finger and was able to resume work without any limitations. Surgical excision with sufficient margin and reconstruction with a reverse digital artery flap is a reliable method to relieve pain due to Pacinian hypertrophy at the fingertip.
PubMed: 34522755
DOI: 10.1016/j.jpra.2021.08.001 -
Experimental Brain Research Dec 2021Single 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...
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.
Topics: Animals; Forelimb; Hand; Mechanoreceptors; Median Nerve; Rats; Skin
PubMed: 34519842
DOI: 10.1007/s00221-021-06193-7 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2022Sea otters (Enhydra lutris) demonstrate rapid, accurate tactile abilities using their paws and facial vibrissae. Anatomical investigations of neural organization in the...
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.
Topics: Animals; Mechanoreceptors; Otters; Skin; Touch; Touch Perception
PubMed: 34425043
DOI: 10.1002/ar.24739 -
Vibration Perception Thresholds of Skin Mechanoreceptors Are Influenced by Different Contact Forces.Journal of Clinical Medicine Jul 2021Determining vibration perception thresholds (VPT) is a central concern of clinical research and science to assess the somatosensory capacity of humans. The response of...
Determining vibration perception thresholds (VPT) is a central concern of clinical research and science to assess the somatosensory capacity of humans. The response of different mechanoreceptors to an increasing contact force has rarely been studied. We hypothesize that increasing contact force leads to a decrease in VPTs of fast-adapting mechanoreceptors in the sole of the human foot. VPTs of 10 healthy subjects were measured at 30 Hz and 200 Hz at the heel of the right foot using a vibration exciter. Contact forces were adjusted precisely between 0.3 N-9.6 N through an integrated force sensor. Significant main effects were found for frequency and contact force. Furthermore, there was a significant interaction for frequency and contact force, meaning that the influence of an increasing contact force was more obvious for the 30 Hz condition. We presume that the principles of contrast enhancement and spatial summation are valid in Meissner and Pacinian corpuscles, respectively. In addition to spatial summation, we presume an effect on Pacinian corpuscles due to their presence in the periosteum or interosseous membrane.
PubMed: 34300249
DOI: 10.3390/jcm10143083 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2022Odontocete cetaceans have undergone profound modifications to their integument and sensory systems and are generally thought to lack specialized exocrine glands that in...
Odontocete cetaceans have undergone profound modifications to their integument and sensory systems and are generally thought to lack specialized exocrine glands that in terrestrial mammals function to produce chemical signals (Thewissen & Nummela, 2008). Keenan-Bateman et al. (2016, 2018), though, introduced an enigmatic exocrine gland, associated with the false gill slit pigmentation pattern in Kogia breviceps. These authors provided a preliminary description of this cervical gill slit gland in their helminthological studies of the parasitic nematode, Crassicauda magna. This study offers the first detailed gross and histological description of this gland and reports upon key differences between immature and mature individuals. Investigation reveals it is a complex, compound tubuloalveolar gland with a well-defined duct that leads to a large, and expandable central chamber, which in turn leads to two caudally projecting diverticula. All regions of the gland contain branched tubular and alveolar secretory regions, although most are found in the caudal diverticula, where the secretory process is holocrine. The gland lies between slips of cutaneous muscle, and is innervated by lamellar corpuscles, resembling Pacinian's corpuscles, suggesting that its secretory product may be actively expressed into the environment. Mature K. breviceps display larger gland size, and increased functional activity in glandular tissues, as compared to immature individuals. These results demonstrate that the cervical gill slit gland of K. breviceps shares morphological features of the specialized, chemical signaling, exocrine glands of terrestrial members of the Cetartiodactyla.
Topics: Animals; Exocrine Glands; Gills; Whales
PubMed: 34288509
DOI: 10.1002/ar.24707 -
International Journal of Women's... Jun 2021Pacinian corpuscle hyperplasia typically presents as a tender nodule on the volar aspect of the palm or digit, often after trauma. Histologically, it presents as one to... (Review)
Review
OBJECTIVE
Pacinian corpuscle hyperplasia typically presents as a tender nodule on the volar aspect of the palm or digit, often after trauma. Histologically, it presents as one to multiple normal-sized to enlarged Pacinian corpuscles in the deep dermis or subcutaneous adipose tissue. Given its rarity, its pathogenesis is debated and nomenclature is poorly defined. Herein, we present a case of Pacinian corpuscle hyperplasia and review the current literature.
METHODS
A literature review was conducted using PubMed with the following search terms: Pacinian corpuscle hyperplasia, Pacinian corpuscle neuroma, Pacinioma, Pacinian corpuscle hypertrophy, and heterotopic Pacinian corpuscles. All case reports and case series were reviewed for histopathologic evidence of true Pacinian corpuscle hyperplasia. Cadaveric studies, cases without true Pacinian corpuscles, and noncutaneous cases were excluded from our analysis.
RESULTS
Sixty patients with Pacinian corpuscle hyperplasia of the hands and feet (65 cases, some with >1 location) were reviewed. The mean age of presentation was 49.5 years, and women accounted for 60% of cases. Pain was the most commonly reported symptom (55 of 65 cases; 84.6%). Forty-five cases (69.2%) were localized to a digit, most commonly the second digit (17 of 65 cases; 26.2%), and 18 of 65 cases (27.6%) affected the palm, primarily the distal palm. Surgical excision was curative in 50 of 65 cases (76.9%).
CONCLUSION
Although relatively uncommon, Pacinian corpuscle hyperplasia should be considered in the differential diagnosis of a tender nodule on the digit or distal palm, particularly after trauma.
PubMed: 34222593
DOI: 10.1016/j.ijwd.2020.10.005 -
Micromachines May 2021The Pacinian corpuscle is a highly sensitive mammalian sensor cell that exhibits a unique band-pass sensitivity to vibrations. The cell achieves this band-pass response...
The Pacinian corpuscle is a highly sensitive mammalian sensor cell that exhibits a unique band-pass sensitivity to vibrations. The cell achieves this band-pass response through the use of 20 to 70 elastic layers entrapping layers of viscous fluid. This paper develops and explores a scalable mechanical model of the Pacinian corpuscle and uses the model to predict the response of synthetic corpuscles, which could be the basis for future vibration sensors. The -3dB point of the biological cell is accurately mimicked using the geometries and materials available with off-the-shelf 3D printers. The artificial corpuscles here are constructed using uncured photoresist within structures printed in a commercial stereolithography (SLA) 3D printer, allowing the creation of trapped fluid layers analogous to the biological cell. Multi-layer artificial Pacinian corpuscles are vibration tested over the range of 20-3000 Hz and the response is in good agreement with the model.
PubMed: 34070189
DOI: 10.3390/mi12050574 -
Frontiers in Neuroanatomy 2021Afferent neurons and their mechanoreceptors provide critical sensory feedback for gait. The anatomical distribution and density of afferents and mechanoreceptors...
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 -null and wild type mice. The -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 -null mice compared to wild type controls paves the way for future site-specific single fiber recordings to provide insight into the role of integrin α1β1 in tactile mechanotransduction.
PubMed: 33737870
DOI: 10.3389/fnana.2021.628711 -
Journal of Microscopy and Ultrastructure 2022The cell is the basic structural unit of all living organisms. Most of the cells forming the human body share the basic components, but there are many categories that... (Review)
Review
The cell is the basic structural unit of all living organisms. Most of the cells forming the human body share the basic components, but there are many categories that have specific light and electron microscopic characteristics. This review shed a light on these cell categories and their morphologies. Stem cell category is the cells responsible for the regeneration of damaged or lost cells, whereas protein-secreting cells are those responsible for the production and secretion of proteins. Protein-secreting cells have specific characters such as basophilic cytoplasm and vesicular nucleus by light microscope; these are confirmed by an electron microscope that shows rough endoplasmic reticulum, Golgi apparatus, secretory granules, and mitochondria. Steroid secreting, ion transporting, and contracting categories have specific morphology. Phagocytic cells such as macrophages and neutrophils are characterized by the presence of many lysosomes and phagosomes. Supporting cells are very important category as they not only support but also usually have another function such as myelin formation in Schwann, blood-brain barrier in astrocytes, or modification of response as in Pacinian corpuscle. Many cells showed interrelated characters between different categories, for example, phagocytic cells are able to contract to perform their function in fighting microorganism. Although we have trillions of cells, yet they only fall in some categories. Each cell category has specific morphological characters confirmed by ultrastructural characters. They all adapted to perform the desired functions.
PubMed: 35832316
DOI: 10.4103/jmau.jmau_74_20 -
Journal of Anatomy Jul 2021Vibration is detected by mechanoreceptors, including Pacinian corpuscles (PCs), which are widely distributed in the human body including the adventitia of large blood...
Vibration is detected by mechanoreceptors, including Pacinian corpuscles (PCs), which are widely distributed in the human body including the adventitia of large blood vessels. Although the distribution of PCs around large limb vessels has been previously reported, there remains no consensus on their distribution in the adventitia of the human deep blood vessels in the upper arm. In addition, the physiological functions of PCs located around the deep limb blood vessels remain largely unknown. This study aimed to elucidate detailed anatomical features and physiological function of lamellar sensory corpuscles structurally identified as PCs using the immunohistochemical methods around the deep vessels in the upper arm. We identified PCs in the connective tissue adjacent to the deep vessels in the upper arm using histological analysis and confirmed that PCs are located in the vascular sheath of the artery and its accompanying vein as well as in the connective tissue surrounding the vascular sheath and nerves. PCs were densely distributed on the distal side of deep vessels near the elbow. We also examined the relationship between vascular sound and pulsating sensation to evaluate the PCs functions around deep arteries and veins and found that the vascular sound made by pressing the brachial arteries in the upper arm was associated with the pulsating sensation of the examinee. Our results suggest that PCs, around deep vessels, function as bathyesthesia sensors by detecting vibration from blood vessels.
Topics: Aged, 80 and over; Arm; Arteries; Female; Humans; Male; Pacinian Corpuscles; Pulsatile Flow
PubMed: 33527396
DOI: 10.1111/joa.13398