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The Journal of Dermatology Oct 2020
Topics: Glomus Tumor; Humans; Neuroma; Pacinian Corpuscles; Peripheral Nervous System Neoplasms
PubMed: 32734616
DOI: 10.1111/1346-8138.15524 -
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 -
The Journal of Neuroscience : the... Oct 2016Axon-Schwann cell interactions are crucial for the development, function, and repair of the peripheral nervous system, but mechanisms underlying communication between...
UNLABELLED
Axon-Schwann cell interactions are crucial for the development, function, and repair of the peripheral nervous system, but mechanisms underlying communication between axons and nonmyelinating Schwann cells are unclear. Here, we show that ER81 is functionally required in a subset of mouse RET mechanosensory neurons for formation of Pacinian corpuscles, which are composed of a single myelinated axon and multiple layers of nonmyelinating Schwann cells, and Ret is required for the maintenance of Er81 expression. Interestingly, Er81 mutants have normal myelination but exhibit deficient interactions between axons and corpuscle-forming nonmyelinating Schwann cells. Finally, ablating Neuregulin-1 (Nrg1) in mechanosensory neurons results in no Pacinian corpuscles, and an Nrg1 isoform not required for communication with myelinating Schwann cells is specifically decreased in Er81-null somatosensory neurons. Collectively, our results suggest that a RET-ER81-NRG1 signaling pathway promotes axon communication with nonmyelinating Schwann cells, and that neurons use distinct mechanisms to interact with different types of Schwann cells.
SIGNIFICANCE STATEMENT
Communication between neurons and Schwann cells is critical for development, normal function, and regeneration of the peripheral nervous system. Despite many studies about axonal communication with myelinating Schwann cells, mostly via a specific isoform of Neuregulin1, the molecular nature of axonal communication with nonmyelinating Schwann cells is poorly understood. Here, we described a RET-ER81-Neuregulin1 signaling pathway in neurons innervating Pacinian corpuscle somatosensory end organs, which is essential for communication between the innervating axon and the end organ nonmyelinating Schwann cells. We also showed that this signaling pathway uses isoforms of Neuregulin1 that are not involved in myelination, providing evidence that neurons use different isoforms of Neuregulin1 to interact with different types of Schwann cells.
Topics: Animals; Axons; DNA-Binding Proteins; Mechanotransduction, Cellular; Mice; Mice, Inbred C57BL; Mutation; Myelin Sheath; Neuregulin-1; Neurons; Pacinian Corpuscles; Peripheral Nerve Injuries; Proto-Oncogene Proteins c-ret; Schwann Cells; Signal Transduction; Transcription Factors
PubMed: 27707970
DOI: 10.1523/JNEUROSCI.2160-16.2016 -
Anatomy & Cell Biology Mar 2017Pacinian corpuscle-like structures were identified in the digital tendon sheaths and nail beds of hands obtained from eight of 12 human fetuses of gestational age 20-34...
Pacinian corpuscle-like structures were identified in the digital tendon sheaths and nail beds of hands obtained from eight of 12 human fetuses of gestational age 20-34 weeks (crown-rump length, 150-290 mm). The aberrant corpuscles were present in tight fibrous tissue connecting the flexor tendon sheath to the dorsal aponeurosis (138 corpuscles in the thumbs and all fingers of eight fetuses); loose fibrous tissue inside the sheath on the dorsal side of the tendon (37 corpuscles in the thumbs and all fingers of four fetuses); and the nail bed (10 clusters in the thumbs and second fingers of four smaller fetuses). The aberrant corpuscles in the tendon sheath were classified into two types: thin and short, with tightly packed lamellae, of diameter 20-40 µm and length 20-200 µm; and thick and long, with loosely packed lamellae, of diameter 70-150 µm and length 0.5-1.5 mm. The small corpuscles tended to form clusters, each containing 5-10 structures. Their similarity indicated that the tight and loose lamellae in these two types of corpuscles corresponded to typical immature and mature corpuscles, respectively, usually distributed along the palmar digital nerve. However, mature, large corpuscles were absent from the nail bed, and most aberrant corpuscles were smaller than typical corpuscles along the nerve. The aberrant corpuscles were apparently incorporated into the tendon sheath or nail bed during fetal vascular development, but they appeared to degenerate after birth due to mechanical stress from the tendon or nail.
PubMed: 28417053
DOI: 10.5115/acb.2017.50.1.33 -
Journal of Anatomy Jun 2019Decline of tactile sensation associated with ageing depends on modifications in skin and both central and peripheral nervous systems. At present, age-related changes in...
Decline of tactile sensation associated with ageing depends on modifications in skin and both central and peripheral nervous systems. At present, age-related changes in the periphery of the somatosensory system, particularly concerning the effects on mechanoreceptors, remain unknown. Here we used immunohistochemistry to analyse the age-dependent changes in Meissner's and Pacinian corpuscles as well as in Merkel cell-neurite complexes. Moreover, variations in the neurotrophic TrkB-BDNF system and the mechanoprotein Piezo2 (involved in maintenance of cutaneous mechanoreceptors and light touch, respectively) were evaluated. The number of Meissner's corpuscles and Merkel cells decreased progressively with ageing. Meissner's corpuscles were smaller, rounded in morphology and located deeper in the dermis, and signs of corpuscular denervation were found in the oldest subjects. Pacinian corpuscles generally showed no relevant age-related alterations. Reduced expression of Piezo2 in the axon of Meissner's corpuscles and in Merkel cells was observed in old subjects, as well was a decline in the BDNF-TrkB neurotrophic system. This study demonstrates that cutaneous Meissner's corpuscles and Merkel cell-neurite complexes (and less evidently Pacinian corpuscles) undergo morphological and size changes during the ageing process, as well as a reduction in terms of density. Furthermore, the mechanoprotein Piezo2 and the neurotrophic TrkB-BDNF system are reduced in aged corpuscles. Taken together, these alterations might explain part of the impairment of the somatosensory system associated with ageing.
Topics: Adult; Aged; Aged, 80 and over; Aging; Female; Fingers; Humans; Male; Mechanoreceptors; Merkel Cells; Middle Aged; Pacinian Corpuscles; Skin; Touch; Young Adult
PubMed: 30924930
DOI: 10.1111/joa.12983 -
Cell and Tissue Research Dec 2021Lamellar corpuscles function as mechanoreceptors in the skin, composed of axon terminals and lamellae constructed by terminal Schwann cells. They are classified into...
Lamellar corpuscles function as mechanoreceptors in the skin, composed of axon terminals and lamellae constructed by terminal Schwann cells. They are classified into Pacinian, Meissner, and simple corpuscles based on histological criteria. Lamellar corpuscles in rat dermal papilla cells have been reported; however, the morphological aspects have yet to be thoroughly investigated. In the present study, we analyzed the enzyme activity, distribution, fine structure, and three-dimensional innervation of lamellar corpuscles in rat plantar skin. The lamellar corpuscles exhibiting non-specific cholinesterase were densely distributed in rat footpads, evident as notable skin elevations, especially at the apex, the highest portion of the ridges in each footpad. In contrast, only a few lamellar corpuscles were found in other plantar skin areas. Lamellar corpuscle was considered composed of a flat axon terminal Schwann cell lamellae, which were roughly concentrically arranged in the dermal papilla. These histological characteristics correspond to those of the simple corpuscle. Moreover, the axon tracing method revealed that one trunk axon innervated several simple corpuscles. The territory of the trunk axons overlapped with each other. Finally, the animals' footprints were analyzed. During the pausing and walking phases, footpads are often in contact with the floor. These results demonstrate that the type of lamellar corpuscles in the dermal papillae of rat plantar skin is a simple corpuscle and implies that their distribution pattern in the plantar skin is convenient for efficient sensing and transmission of mechanical stimuli from the ground.
Topics: Animals; Foot; Rats; Rats, Wistar; Sensory Receptor Cells; Skin
PubMed: 34562148
DOI: 10.1007/s00441-021-03525-5 -
Journal of Clinical Medicine Oct 2021Distal diabetic sensorimotor polyneuropathy (DDSP) is the most prevalent form of diabetic neuropathy, and some of the patients develop gradual pain. Specialized sensory...
Distal diabetic sensorimotor polyneuropathy (DDSP) is the most prevalent form of diabetic neuropathy, and some of the patients develop gradual pain. Specialized sensory structures present in the skin encode different modalities of somatosensitivity such as temperature, touch, and pain. The cutaneous sensory structures responsible for the qualities of mechanosensitivity (fine touch, vibration) are collectively known as cutaneous mechanoreceptors (Meissner corpuscles, Pacinian corpuscles, and Merkel cell-axonal complexes), which results are altered during diabetes. Here, we used immunohistochemistry to analyze the density, localization within the dermis, arrangement of corpuscular components (axons and Schwann-like cells), and expression of putative mechanoproteins (PIEZO2, ASIC2, and TRPV4) in cutaneous mechanoreceptors of subjects suffering clinically diagnosed non-painful and painful distal diabetic sensorimotor polyneuropathy. The number of Meissner corpuscles, Pacinian corpuscles, and Merkel cells was found to be severely decreased in the non-painful presentation of the disease, and almost disappeared in the painful presentation. Furthermore, there was a marked reduction in the expression of axonal and Schwann-like cell markers (with are characteristics of corpuscular denervation) as well as of all investigated mechanoproteins in the non-painful distal diabetic sensorimotor polyneuropathy, and these were absent in the painful form. Taken together, these alterations might explain, at least partly, the impairment of mechanosensitivity system associated with distal diabetic sensorimotor polyneuropathy. Furthermore, our results support that an increasing severity of DDSP may increase the risk of developing painful neuropathic symptoms. However, why the absence of cutaneous mechanoreceptors is associated with pain remains to be elucidated.
PubMed: 34640627
DOI: 10.3390/jcm10194609 -
Annals of Anatomy = Anatomischer... Aug 2022PIEZO2 is a transmembrane protein forming part of an ion channel required for mechanotransduction. In humans, PIEZO2 is present in axon terminals of adult Meissner and...
BACKGROUND
PIEZO2 is a transmembrane protein forming part of an ion channel required for mechanotransduction. In humans, PIEZO2 is present in axon terminals of adult Meissner and Pacinian corpuscles, as well as Merkel cells in Merkel cell-neurite complexes.
METHODS
To study the acquisition of functional capability for mechanotransduction of developing type I slowly adapting low-threshold mechanoreceptors, i.e., Merkel cell-neurite complexes, a battery of immunohistochemical and immunofluorescence techniques was performed on human skin specimens covering the whole development and growth, from 11 weeks of estimated gestational age to 20 years of life. In addition, developmental expression of PIEZO2 type I (Meissner's corpuscles) and type II (Pacinian corpuscles) rapidly adapting mechanoreceptors was studied in parallel.
RESULTS
The first evidence of Merkel cells showing the typical morphology and placement was at 13 weeks of estimated gestation age, and at this time positive immunoreactivity for PIEZO2 was achieved. PIEZO2 expression in axons terminals started at 23 WEGA in Pacinian corpuscles and at 36 WEGA in the case of Meissner corpuscles. The occurrence of PIEZO2 in Merkel cells, Meissner and Pacinian corpuscles was maintained for all the time investigated. Interestingly PIEZO2 was absent in most Aβ type I slowly adapting low-threshold mechanoreceptors that innervate MC while it was regularly present in most Aβ type I and type II rapidly adapting low-threshold mechanoreceptors that supplies Meissner and Pacinian corpuscles.
CONCLUSION
The present results provide evidence that human cutaneous mechanoreceptors could perform mechanotransduction already during embryonic development.
Topics: Adult; Female; Humans; Ion Channels; Mechanoreceptors; Mechanotransduction, Cellular; Merkel Cells; Pacinian Corpuscles; Pregnancy; Skin
PubMed: 35523396
DOI: 10.1016/j.aanat.2022.151953 -
Scientific Reports Nov 2023Spatial acuity is a fundamental property of any sensory system. In the case of the somatosensory system, the two-point discrimination (2PD) test has long been used to...
Spatial acuity is a fundamental property of any sensory system. In the case of the somatosensory system, the two-point discrimination (2PD) test has long been used to investigate tactile spatial resolution. However, the somatosensory system comprises three main mechanoreceptive channels: the slowly adapting channel (SA) responds to steady pressure, the rapidly adapting channel (RA) responds to low-frequency vibration, and the Pacinian channel (PC) responds to high-frequency vibration. The use of mechanical stimuli in the classical 2PD test means that previous studies on tactile acuity have primarily focussed on the pressure-sensitive channel alone, while neglecting other submodalities. Here, we used a novel ultrasound stimulation to systematically investigate the spatial resolution of the two main vibrotactile channels. Contrary to the textbook view of poor spatial resolution for PC-like stimuli, across four experiments we found that high-frequency vibration produced surprisingly good spatial acuity. This effect remained after controlling for interchannel differences in stimulus detectability and perceived intensity. Laser doppler vibrometry experiments confirmed that the acuity of the PC channel was not simply an artifact of the skin's resonance to high-frequency mechanical stimulation. Thus, PC receptors may transmit substantial spatial information, despite their sparse distribution, deep location, and large receptive fields.
Topics: Touch; Mechanoreceptors; Pacinian Corpuscles; Afferent Pathways; Vibration
PubMed: 38036579
DOI: 10.1038/s41598-023-48037-0 -
Foot (Edinburgh, Scotland) Dec 2021Pacinian hyperplasia in the human body has been rarely described in the literature with most cases reported involving the hand (Fassola et al., 2019). This hyperplasia...
Pacinian hyperplasia in the human body has been rarely described in the literature with most cases reported involving the hand (Fassola et al., 2019). This hyperplasia is considered a reactive lesion as opposed to a neoplasm (Satge et al., 2001), with the most common presenting complaint being pain and swelling (Fassola et al., 2019). In this study, a case of bilateral Pacinian corpuscle hyperplasia in the adult foot not previously described in the literature is presented.
Topics: Adult; Hand; Humans; Hyperplasia; Neuroma; Pacinian Corpuscles; Peripheral Nervous System Neoplasms
PubMed: 33036838
DOI: 10.1016/j.foot.2020.101709