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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 -
Shoulder & Elbow Aug 2019The topographic arrangement of sensory receptors in the human elbow joint capsule is pertinent to their role in the transmission of neural signals. The signals from...
BACKGROUND
The topographic arrangement of sensory receptors in the human elbow joint capsule is pertinent to their role in the transmission of neural signals. The signals from stimuli in the joint are concisely delivered via afferent pathways to allow recognition of pain and proprioception. Sensory receptors in the elbow joint include mechanoreceptors and free nerve endings acting as nociceptors, although the distribution of each of the structures has not been determined, despite their importance for the integrity of the joint. We therefore aimed to investigate the neuroanatomical distribution and densities of mechanoreceptors and free nerve endings in the capsule of the elbow, at the same time as considering surgical approaches that would result in the minimum insult to them.
METHODS
Four elbow joint capsules were harvested from fresh cadavers. The specimens were carefully separated from adjacent osteoligamentous attachments and the capsular complex was stained with a modified gold chloride method. Evaluations of free nerve endings, and Golgi, Ruffini and Pacinian corpuscles were performed under an inverted light microscope. The number and density of each structure were recorded.
RESULTS
Ruffini corpuscles observed to be the dominant mechanoreceptor type. No Golgi corpuscle was observed. Free nerve endings were found at the highest density at posterodistal sites, whereas mechanoreceptors were most frequent at bony attachment sites.
CONCLUSIONS
A consistent distribution pattern of articular sensory receptors was observed, which allows further understanding of elbow pathology. An awareness of the neuroanatomical distribution of sensory receptors in the elbow joint capsule may allow their preservation during surgical procedures for elbow joint pathology.
PubMed: 31316591
DOI: 10.1177/1758573218760245 -
The Journal of Hand Surgery, European... Nov 2019Tumours involving Pacinian corpuscles are rare. The literature identifies two main pathological disorders: the Pacinian corpuscle neuroma or hyperplasia and the Pacinian...
Tumours involving Pacinian corpuscles are rare. The literature identifies two main pathological disorders: the Pacinian corpuscle neuroma or hyperplasia and the Pacinian corpuscle neurofibroma. Published data are confusing and at times conflicting. This systematic review summarizes the available data in order to support clinicians in the differential diagnosis with other tumours responsible for unclear symptoms in the hands and fingers. We identified 67 pertinent articles. Although some similarities have been described, the two tumours have relevant differences, specifically when comparing age of the patient, location, symptoms, characteristic of a mass, and aetiology. All these factors should be taken into account in order to improve diagnostic accuracy. Despite the low incidence of unsuccessful surgeries, extraordinary measures are occasionally necessary to achieve complete resolution of symptoms.
Topics: Diagnosis, Differential; Hand; Humans; Hyperplasia; Neurofibroma; Neuroma; Pacinian Corpuscles
PubMed: 31156019
DOI: 10.1177/1753193419852118 -
Skeletal Radiology Oct 2019To provide microdissection and histological confirmation of normal Pacinian corpuscles prospectively identified using MRI in a cadaver model.
OBJECTIVE
To provide microdissection and histological confirmation of normal Pacinian corpuscles prospectively identified using MRI in a cadaver model.
METHODS
3-T MRI of a cadaveric hand specimen was performed with fiduciary markers on the skin. Based on previous descriptions, subcutaneous nodules representing presumed Pacinian corpuscles were localized with respect to the skin markers, and their sizes and depths were recorded. Focused ultrasound was performed to attempt to visualize the corpuscles. Subsequent microdissection was then performed and the presence and location of Pacinian corpuscles were recorded and compared with the findings on MRI. Histological evaluation for each identified corpuscle was performed.
RESULTS
The MRI demonstrated 11 T2-hyperintense palmar subcutaneous nodules around the second through fifth metacarpophalangeal joints. None was visible sonographically. The first eight were dissected and proved to be normal Pacinian corpuscles histologically. In sites devoid of subcutaneous nodules on MRI, subsequent dissection failed to reveal any corpuscles.
CONCLUSION
On MRI, normal Pacinian corpuscles appear as round or oval, T2-hyperintense subcutaneous nodules in the palms, clustered around the metacarpophalangeal joints, and should not be mistaken for pathological conditions.
Topics: Cadaver; Hand; Humans; Magnetic Resonance Imaging; Pacinian Corpuscles; Prospective Studies
PubMed: 31069468
DOI: 10.1007/s00256-019-03223-y -
Annals of Anatomy = Anatomischer... Jul 2019Pacinian corpuscles are onion bulb-like multilayered mechanoreceptors that consist of a complicated structure of axon terminals, Schwann related cells (inner core),...
Pacinian corpuscles are onion bulb-like multilayered mechanoreceptors that consist of a complicated structure of axon terminals, Schwann related cells (inner core), endoneural related cells (intermediate layer) and perineurial related cells (outer core-capsule). The cells forming those compartments are continuous and share the properties of that covering the nerve fibers. Small leucine-rich proteoglycans are major proteoglycans of the extracellular matrix and regulate collagen fibrillogenesis, cell signalling pathways and extracellular matrix assembly. Here we used immunohistochemistry to investigate the distribution of class I (biglycan, decorin, asporin, ECM2 and ECMX) and class II (fibromodulin, lumican, prolargin, keratocan and osteoadherin) small leucine-rich proteoglycans in human cutaneous Pacinian corpuscles. The distribution of these compounds was: the inner core express decorin, biglycan, lumican, fibromodulin, osteoadherin; the intermediate layer display immunoreactivity for osteoadherin; the outer core biglycan, decorin, lumican, fibromodulin and osteoadherin; and the capsule contains biglycan, decorin, fibromodulin, and lumican. Asporin, prolargin and keratocan were undetectable. These results complement our knowledge about the distribution of small leucine-rich proteoglycans in human Pacinian corpuscles, and help to understand the composition of the extracellular matrix in these sensory formations.
Topics: Adolescent; Adult; Animals; Antigens, CD34; Biglycan; Child; Decorin; Equidae; Extracellular Matrix Proteins; Fibromodulin; Fingers; Fluorescent Antibody Technique; Goats; Humans; Immunohistochemistry; Mice; Middle Aged; Pacinian Corpuscles; Proteoglycans; Rabbits; S100 Proteins; Skin; Vimentin; Young Adult
PubMed: 31005573
DOI: 10.1016/j.aanat.2019.02.007 -
GMS Interdisciplinary Plastic and... 2019Vater-Pacini neuromas are rare causes of severe pain in the phalanges. The cause of this change in the tactile corpuscles is unknown. A traumatic cause has been...
Vater-Pacini neuromas are rare causes of severe pain in the phalanges. The cause of this change in the tactile corpuscles is unknown. A traumatic cause has been plausibly demonstrated, at least in some cases. Here, the rare occurrence of a Vater-Pacini neuroma in a patient with neurofibromatosis type 1 is reported. The discussion addresses the difficulties of terminology and current diagnostic procedures for differentiating small nodular masses of the palm and digits. The surgical treatment leads to rapid relief of the symptoms.
PubMed: 30984511
DOI: 10.3205/iprs000129 -
IEEE Transactions on Haptics 2019Recognizing and discriminating vibrotactile stimuli is an essential function of the Pacinian corpuscle. This function has been studied at length in both a computational...
Recognizing and discriminating vibrotactile stimuli is an essential function of the Pacinian corpuscle. This function has been studied at length in both a computational and an experimental setting, but the two approaches have rarely been compared, especially when the computational model has a high level of structural detail. In this paper, we explored whether the predictions of a multiscale, multiphysical computational model of the Pacinian corpuscle can predict the outcome of a corresponding psychophysical experiment. The discrimination test involved either two simple stimuli with frequency in the 160-500 Hz range, or two complex stimuli formed by combining the waveforms for a 100-Hz stimulus with a second stimulus in the 160-500 Hz range. The subjects' ability to distinguish between the simple stimuli increased as the frequency increased, a result consistent with the model predictions for the same stimuli. The model also predicted correctly that subjects would find the complex stimuli more difficult to distinguish than the simple ones and also that the discriminability of the complex stimuli would show no trend with frequency difference.
Topics: Discrimination, Psychological; Humans; Models, Theoretical; Pacinian Corpuscles; Sensory Thresholds; Touch; Touch Perception; Vibration
PubMed: 30932849
DOI: 10.1109/TOH.2019.2903500 -
Journal of Molecular Histology Jun 2019At present, a few studies have been done on the changes in the distribution, morphology and quantity of mechanoreceptors in anterior cruciate ligament (ACL) with age. In...
At present, a few studies have been done on the changes in the distribution, morphology and quantity of mechanoreceptors in anterior cruciate ligament (ACL) with age. In this study, we observed the changes in mechanoreceptors of healthy rabbits' ACL with age. We found that rabbits' ACLs contained 5 kinds of mechanoreceptors including Ruffini corpuscles, Pacinian corpuscles, Golgitendon bodies, free nerve endings and atypical mechanoreceptors. In each ACL, free nerve endings were the most followed by Ruffini corpuscles, Pacinian corpuscles, Golgitendon bodies and atypical mechanoreceptors in the younger than one-old rabbits. Most of the mechanoreceptors were distributed in the synovium near the attachment points of ACL with the femur and tibia. The total quantity of mechanoreceptors were the most in the 3- and 6-month groups, but did not show a significant difference between the two group (P > 0.05). However, there were significant differences in the total quantity of mechanoreceptors between other groups (all P < 0.05). RT-PCR indicated that NEFM and S100B levels increased with age, and reached a peak in the 1-year group with significant differences as compared to other groups. NEFM and S100B levels were the second in 6-month and 2-year groups and the lowest in the 1-week group. We can conclude that in rabbits' ACLs, free nerve endings are the most common, followed by Ruffini corpuscles, Pacinian corpuscles and Golgitendon bodies. The total quantity of mechanoreceptors reaches a peak in 3 months, while NEFM and S100B reach a peak in 1 year.
Topics: Aging; Animals; Anterior Cruciate Ligament; Disease Models, Animal; Humans; Mechanoreceptors; Neurofilament Proteins; Rabbits; S100 Calcium Binding Protein beta Subunit; Tibia
PubMed: 30927131
DOI: 10.1007/s10735-019-09820-4 -
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 -
Journal of Anatomy Jun 2019The ligament of the head of femur (LHF), or ligamentum teres, is believed to provide blood supply to the head of femur and mechanical stability to the hip joint. But...
The ligament of the head of femur (LHF), or ligamentum teres, is believed to provide blood supply to the head of femur and mechanical stability to the hip joint. But these functions in the adult are often debated. The existence and distribution of neurovascular structures within the ligament are not widely documented. This study examined the blood vessels and nervous tissue within the LHF to determine whether the ligament may have a vascular and proprioceptive function at the hip joint. Histological sections from the LHF from 10 embalmed hips (six female, four male; mean age 80.4 ± 8.7 years) were cut at three levels: the foveal attachment, mid-length and its base where it attaches to the transverse acetabular ligament. Sections were stained with haematoxylin and eosin to study general tissue architecture or with von Willebrand factor and neurofilament to identify blood vessels and nervous tissue, respectively. The proportion of the ligament's cross-sectional area occupied by blood vessels was expressed as a vascularity index (VI). Nerve endings within the ligament were identified and morphologically classified. Comparisons between the VI at the three levels, or between the tissue layers of the ligament, were made using 95% confidence intervals; statistical significance was set P < 0.05. The ligament tissue comprised three distinct layers: a synovial lining with cuboidal cells, a sub-synovial zone formed of loose connective tissue and the ligament proper composed of dense collagen bundles. Patent blood vessels and nerve fibres were present both in the sub-synovial zone and the ligament proper; Pacinian corpuscles and free nerve endings were found scattered only in the sub-synovial zone. The VI of the ligament proper at the fovea was significantly higher than its middle (P = 0.01) and basal levels (P = 0.04); it was also higher than that of the sub-synovial layer (P = 0.04). The LHF has three histologically distinct zones, and blood vessels and nerves are distributed both in the sub-synovial layer and ligament proper. Higher vascularity within the ligament proper at its foveal insertion suggests a possible nutritive role of the LHF to the adult head of femur. The presence of nerves and nerve receptors indicates the ligament is involved in the perception of pain and proprioception, thereby contributing to mechanical stability of the joint.
Topics: Aged; Aged, 80 and over; Cadaver; Female; Femur; Hip Joint; Humans; Male; Round Ligament of Femur
PubMed: 30882902
DOI: 10.1111/joa.12979