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Journal of Molecular Histology Jun 2020Here we investigated the morphology, quantity, distribution and gene expression of mechanoreceptors in the anterior cruciate ligament (ACL), posterior cruciate ligament...
Here we investigated the morphology, quantity, distribution and gene expression of mechanoreceptors in the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), lateral collateral ligament (LCL), patellar tendon (PaT) and popliteal tendon (PoT) of the knee joint. Twelve 6-month-old rabbits were divided into two groups. In one group, the ACL, PCL, MCL, LCL, PaT and PoT were collected to observe the morphology, distribution and quantity of mechanoreceptors. In another group, the ACL, PCL, MCL, LCL, PaT and PoT of bilateral knee joints were used to determine S100B, CGRP and NEFM gene levels. Five types of mechanoreceptors were observed including Ruffini corpuscles, Pacinian corpuscles, Golgi-tendon bodies, atypical mechanoreceptors and free nerve endings. The total amount of mechanoreceptors was significantly lower in MCL, LCL, PaT and PoT as compared with ACL and PCL (P < 0.001). All examined mechanoreceptors were present in ACL, PCL and LCL. However, no Pacinian corpuscles and Golgi-tendon bodies were found in MCL and PoT as well as Pacinian corpuscles were not observed in PaT. The present study indicated that the levels of NEFM was significantly lower in PCL, MCL, LCL, PaT and PoT as compared with ACL (P < 0.05), but there was no significant difference in CGRP level between ACL and other ligaments except LCL (P > 0.05). Thus, the quantity, type and gene expression of mechanoreceptors are different in various ligaments. Thus, the quantity and distribution of mechanoreceptors may be related to ligament's function.
Topics: Animals; Anterior Cruciate Ligament; Calcitonin Gene-Related Peptide; Gene Expression; Knee Joint; Male; Mechanoreceptors; Medial Collateral Ligament, Knee; Neurofilament Proteins; Posterior Cruciate Ligament; Rabbits; S100 Calcium Binding Protein beta Subunit
PubMed: 32356233
DOI: 10.1007/s10735-020-09875-8 -
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 -
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 -
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 -
Romanian Journal of Morphology and... 2020Lamellar (Pacinian) corpuscle is a cutaneous encapsulated sensory corpuscle, mainly functioning as a rapidly adapting low-threshold mechanoreceptor with characteristic...
Lamellar (Pacinian) corpuscle is a cutaneous encapsulated sensory corpuscle, mainly functioning as a rapidly adapting low-threshold mechanoreceptor with characteristic "onion skin"-like appearance. Even though the Pacinian corpuscle is typically located in the skin, histomorphologically and confirmed by using immunohistochemical methods, we have identified it within the interstitium of the thymus of a newborn with congenital heart defect. To the best of our knowledge, this is the first such account ever to be published. The structure of the thymic Pacinian corpuscle was the same as the Pacinian corpuscle in the skin. The ectopic thymic Pacinian corpuscle can be hypothetically explained as the consequence of impaired migration of neural crest cells, since neural crest-derived cells play an important role in the development of the Pacinian corpuscle, as well as the thymus and heart. In general, the occurrence of ectopic Pacinian corpuscle in different organs is rare. In the scientific literature, there are reports of its sporadic presence in the pancreas, in the lymph nodes, inside the prostate and the urinary bladder wall. Our report presents the first described case of the Pacinian corpuscle in a heterotopic location in the thymus. Similar to other incidental findings of this anatomic structure, explanation of its ectopic development, as well as its local function remains only speculative.
Topics: Humans; Infant, Newborn; Male; Pacinian Corpuscles; Thymus Gland
PubMed: 32747922
DOI: 10.47162/RJME.61.1.33 -
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 -
Perception Aug 2017Although the ability of vibration to reduce pain has been extensively documented, an occasional participant reports that vibration increases pain. For pain patients,...
Although the ability of vibration to reduce pain has been extensively documented, an occasional participant reports that vibration increases pain. For pain patients, such reports may reflect pathophysiology, but this is unlikely in studies of experimental pain in healthy participants. In the present series of experiments on 27 pain-free individuals, we manipulated both the frequency (12, 50, and 80 Hz) and amplitude of vibration to more fully characterize vibratory pain modulation. The noxious stimulus was pressure applied to a finger, and vibration was delivered to the fleshy palmar pad at the base of the same finger. Subjects continuously reported pain on a Visual Analog Scale. Intermittent vibration was used to minimize peripheral vibratory adaptation. Pain records at 12 and 50 Hz were similar; pooling them revealed significant hypoalgesia at the highest amplitude. At 80 Hz, in contrast, the middle amplitude produced hypoalgesia, but a significant shift toward hyperalgesia occurred at the highest amplitude. The strong correlation ( r = .81) between the Pacinian-weighted power of a vibration and the absolute value of the pain modulation it produces indicates that the Pacinian system plays a key role in vibratory hypoalgesia or hyperalgesia.
Topics: Adult; Female; Fingers; Humans; Male; Nociception; Pacinian Corpuscles; Pain Measurement; Vibration; Young Adult
PubMed: 28715995
DOI: 10.1177/0301006617694630 -
Anatomical Record (Hoboken, N.J. : 2007) Jan 2018The detailed distribution of Pacinian corpuscles was evaluated by viewing the transverse sections of all fingers and thumbs, including the interdigital areas, from eight...
The detailed distribution of Pacinian corpuscles was evaluated by viewing the transverse sections of all fingers and thumbs, including the interdigital areas, from eight hands of five fetuses of gestational age 28-33 weeks (crown-rump length 230-290 mm). Among the 40 fingers and thumbs, serial sections were prepared for 3D reconstructions of nerve elements in the distal and middle phalangeal segments of three fifth fingers; in these three fingers, the distal segment contained 45-75 Pacinian corpuscles. These Pacinian corpuscles were 0.2-1.0 mm in length and 0.05-0.3 mm in thickness, oriented along the proximodistal axis and arranged along the palmar digital nerve branches. Other than beneath the digital skin, small corpuscles (<0.1 mm in thickness) were observed within the tendon sheath of the flexors in the middle or distal segment of five fetuses and in the nail beds of four fetuses. Clusters of 5-20 corpuscles formed bouquet- or tree-like arrangements along neurovascular bundles in the fingers, thumbs and interdigital areas. Because the space beneath the skin was thick and loose in the interdigital area, trees in the interdigital area were up to 2 mm long. Regardless of site, the central core of each corpuscle was positive for S100 protein, while the core and parts of the capillaries in the corpuscle were weakly positive for nestin. Because corpuscles in the tendon sheath and nail bed, as well as bouquet- and tree-like arrangements of corpuscles, have not been reported in adults, these morphologies are likely specific to fetuses. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:154-165, 2018. © 2017 Wiley Periodicals, Inc.
Topics: Anatomy, Cross-Sectional; Female; Fetus; Fingers; Humans; Imaging, Three-Dimensional; Immunohistochemistry; Male; Nestin; Pacinian Corpuscles; S100 Proteins; Skin; Thumb
PubMed: 29059706
DOI: 10.1002/ar.23707 -
Orthopaedics & Traumatology, Surgery &... Apr 2018The human elbow maintains its stability mainly through its bony structure. Stability is enhanced by ligamentous structures. To allow the ligamento-muscular reflex, which...
BACKGROUND
The human elbow maintains its stability mainly through its bony structure. Stability is enhanced by ligamentous structures. To allow the ligamento-muscular reflex, which protects against strain and stress, mechanoreceptors are embedded in the ligament. This report describes the existence and the distribution of the elbow medial collateral ligaments (MCLs) mechanoreceptors.
HYPOTHESIS
The bony attachment site has the highest density of mechanoreceptors, and the anterior part has the highest density of mechanoreceptors.
MATERIALS AND METHODS
Eight MCLs of elbow from fresh frozen cadavers were used. The MCLs were harvested deep to the periosteum from the medial epicondyle to the ulna. The fan-shaped ligaments were divided into six regions of interest (ROI) and stained with modified gold chloride stain. Specimens were evaluated under a light microscope. Golgi, Ruffini, and Pacinian corpuscles were found in every specimen. The number and the distribution of each mechanoreceptor in each ROI were recorded. The density of each mechanoreceptor was calculated in regards to its volume.
RESULTS
Golgi, Ruffini, and Pacinian corpuscles were seen in the ligament with small nerve fibers. Ruffini corpuscles had the highest median density of all three corpuscles. The median corpuscle density was higher in the anterior than in the posterior part and higher in the bony attachment than in the mid-substance site except for Golgi corpuscle.
CONCLUSION
The three typical types of mechanoreceptors were identified in human MCL with the anterior part and bony attachment as the dominant distribution site.
LEVEL OF EVIDENCE
Basic Science Study.
Topics: Aged; Cadaver; Collateral Ligaments; Coloring Agents; Elbow; Female; Gold Compounds; Humans; Male; Mechanoreceptors; Middle Aged
PubMed: 29410196
DOI: 10.1016/j.otsr.2018.01.005 -
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