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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 -
Anatomical Record (Hoboken, N.J. : 2007) Apr 2018
Topics: Aged; Humans; Lymph Node Excision; Lymph Nodes; Male; Pacinian Corpuscles; Prostatectomy; Prostatic Neoplasms
PubMed: 29281859
DOI: 10.1002/ar.23765 -
The Journal of the Acoustical Society... Nov 2017Two experiments were conducted on an upright and a grand piano, both either producing string vibrations or conversely being silent after the initial keypress, while... (Comparative Study)
Comparative Study
Two experiments were conducted on an upright and a grand piano, both either producing string vibrations or conversely being silent after the initial keypress, while pianists were listening to the feedback from a synthesizer through insulating headphones. In a quality experiment, participants unaware of the silent mode were asked to play freely and then rate the instrument according to a set of attributes and general preference. Participants preferred the vibrating over the silent setup, and preference ratings were associated to auditory attributes of richness and naturalness in the low and middle ranges. Another experiment on the same setup measured the detection of vibrations at the keyboard, while pianists played notes and chords of varying dynamics and duration. Sensitivity to string vibrations was highest in the lowest register and gradually decreased up to note D5. After the percussive transient, the tactile stimuli exhibited spectral peaks of acceleration whose perceptibility was demonstrated by tests conducted in active touch conditions. The two experiments confirm that piano performers perceive vibratory cues of strings mediated by spectral and spatial summations occurring in the Pacinian system in their fingertips, and suggest that such cues play a role in the evaluation of quality of the musical instrument.
Topics: Acoustic Stimulation; Adult; Auditory Perception; Auditory Threshold; Cues; Female; Fingers; Humans; Judgment; Loudness Perception; Male; Motion; Music; Pacinian Corpuscles; Pitch Perception; Sound; Time Factors; Touch; Touch Perception; Vibration
PubMed: 29195444
DOI: 10.1121/1.5009659 -
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 -
Journal of Anatomy Dec 2017The transformation of mechanical energy into electrical signals is the first step in mechanotransduction in the peripheral sensory nervous system and relies on the...
The transformation of mechanical energy into electrical signals is the first step in mechanotransduction in the peripheral sensory nervous system and relies on the presence of mechanically gated ion channels within specialized sensory organs called mechanoreceptors. Piezo2 is a vertebrate stretch-gated ion channel necessary for mechanosensitive channels in mammalian cells. Functionally, it is related to light touch, which has been detected in murine cutaneous Merkel cell-neurite complexes, Meissner-like corpuscles and lanceolate nerve endings. To the best of our knowledge, the occurrence of Piezo2 in human cutaneous mechanoreceptors has never been investigated. Here, we used simple and double immunohistochemistry to investigate the occurrence of Piezo2 in human digital glabrous skin. Piezo2 immunoreactivity was detected in approximately 80% of morphologically and immunohistochemically characterized (cytokeratin 20 , chromogranin A and synaptophisin ) Merkel cells. Most of them were in close contact with Piezo2 nerve fibre profiles. Moreover, the axon, but not the lamellar cells, of Meissner's corpuscles was also Piezo2 , but other mechanoreceptors, i.e. Pacinian or Ruffini's corpuscles, were devoid of immunoreactivity. Piezo2 was also observed in non-nervous tissue, especially the basal keratinocytes, endothelial cells and sweat glands. The present results demonstrate the occurrence of Piezo2 in cutaneous sensory nerve formations that functionally work as slowly adapting (Merkel cells) and rapidly adapting (Meissner's corpuscles) low-threshold mechanoreceptors and are related to fine and discriminative touch but not to vibration or hard touch. These data offer additional insight into the molecular basis of mechanosensing in humans.
Topics: Adult; Female; Fingers; Humans; Ion Channels; Male; Mechanoreceptors; Mechanotransduction, Cellular; Merkel Cells; Middle Aged; Skin; Young Adult
PubMed: 28905996
DOI: 10.1111/joa.12688 -
Anatomical Record (Hoboken, N.J. : 2007) Dec 2017The occurrence of Pacinian corpuscles associated to lymph nodes is an anatomical rarity and very scarce information exists in this regard. Here we examined...
The occurrence of Pacinian corpuscles associated to lymph nodes is an anatomical rarity and very scarce information exists in this regard. Here we examined immunohistochemically four Pacinian corpuscles found in the close vicinity of the hiliar blood vessels of lymph nodes (2 cervical, 1 axillary, and 1 inguinal) during routine surgical pathology. Pacinian corpuscles were normally arranged and displayed a pattern of protein distribution as follows: the axon was positive for neurofilament proteins and neuron specific enolase, the inner core cells showed intense S100 protein and vimentin immunostaining while they were negative for glial fibrillary acidic protein, type IV collagen and glucose transporter 1; vimentin, type IV collagen, and glucose transporter 1 were also observed also in the outer-core and the capsule. These results are in agreement with those reported for cutaneous Pacinian corpuscles, demonstrating that the immunohistochemical profile of these corpuscles is independent of its anatomical localization. The possible functional significance of Pacinian corpuscles in lymph nodes is discussed. Anat Rec, 300:2233-2238, 2017. © 2017 Wiley Periodicals, Inc.
Topics: Acquired Immunodeficiency Syndrome; Aged; Aged, 80 and over; Hernia, Inguinal; Humans; Lymph Nodes; Middle Aged; Neoplasms; Pacinian Corpuscles
PubMed: 28806498
DOI: 10.1002/ar.23679 -
American Journal of Veterinary Research Jun 2017OBJECTIVE To examine the equine foot for the presence of sensory receptors including Merkel cells and small lamellated Pacinian-like corpuscles (SLPCs). SAMPLE Forefeet...
OBJECTIVE To examine the equine foot for the presence of sensory receptors including Merkel cells and small lamellated Pacinian-like corpuscles (SLPCs). SAMPLE Forefeet obtained from 7 horses following euthanasia for reasons other than foot disease. PROCEDURES Disarticulated feet were cut into either sagittal sections or cross sections and immersed in neutral-buffered 4% formalin. Following fixation, samples were obtained from the midline of the dorsal aspect of the hoof wall and from the frog (cuneus ungulae) between the apex and central sulcus. The formalin-fixed, paraffin-embedded hoof wall and frog sections were routinely processed for peroxidase immunohistochemistry and stained with H&E, Alcian blue, and Masson trichrome stains for histologic evaluation. RESULTS Sensory myelinated nerves and specific receptors were identified within the epidermal and dermal tissues of the equine foot including the hoof wall laminae, coronet, and frog. Merkel cells were identified with specific antisera to villin, cytokeratin 20, and protein gene product 9.5 in coronet epidermis and hoof wall. These cells were interspersed among basilar keratinocytes within the frog, coronary epidermis, and secondary epidermal laminae. The SLPCs were present within the superficial dermis associated with the central ridge of the frog (ie, frog stay). Numerous S100 protein and protein gene product 9.5 immunoreactive sensory nerves in close proximity to these receptors were present throughout the dermal tissues within both the frog and hoof wall. CONCLUSIONS AND CLINICAL RELEVANCE The presence of Merkel cells and SLPCs that are known to detect tactile and vibrational stimuli, respectively, further defined the diverse range of neural elements within the equine foot.
Topics: Animals; Foot; Hoof and Claw; Horses; Immunohistochemistry; Merkel Cells; S100 Proteins; Sensory Receptor Cells; Ubiquitin Thiolesterase
PubMed: 28541151
DOI: 10.2460/ajvr.78.6.659 -
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 -
Magnetic Resonance in Medicine Jan 2018To demonstrate a dedicated setup for ultrahigh resolution MR imaging of the human finger in vivo.
PURPOSE
To demonstrate a dedicated setup for ultrahigh resolution MR imaging of the human finger in vivo.
METHODS
A radiofrequency coil was designed for optimized signal homogeneity and sensitivity in the finger at ultrahigh magnetic field strength (7 T), providing high measurement sensitivity. Imaging sequences (2D turbo-spin echo (TSE) and 3D magnetization-prepared rapid acquisition gradient echo (MPRAGE)) were adapted for high spatial resolution and good contrast of different tissues in the finger, while keeping acquisition time below 10 minutes. Data was postprocessed to display finger structures in three dimensions.
RESULTS
3D MPRAGE data with isotropic resolution of 200 µm, along with 2D TSE images with in-plane resolutions of 58 × 78 µm and 100 × 97 µm , allowed clear identification of various anatomical features such as bone and bone marrow, tendons and annular ligaments, cartilage, arteries and veins, nerves, and Pacinian corpuscles.
CONCLUSION
Using this dedicated finger coil at 7 T, together with adapted acquisition sequences, it is possible to depict the internal structures of the human finger in vivo within patient-compatible measurement time. It may serve as a tool for diagnosis and treatment monitoring in pathologies ranging from inflammatory or erosive joint diseases to injuries of tendons and ligaments to nervous or vascular disorders in the finger. Magn Reson Med 79:588-592, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Topics: Computer Simulation; Fingers; Humans; Imaging, Three-Dimensional; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Models, Anatomic; Phantoms, Imaging; Radio Waves; Signal-To-Noise Ratio
PubMed: 28295563
DOI: 10.1002/mrm.26645 -
PloS One 2016An Asian spice, Szechuan pepper (sanshool), is well known for the tingling sensation it induces on the mouth and on the lips. Electrophysiological studies have revealed...
An Asian spice, Szechuan pepper (sanshool), is well known for the tingling sensation it induces on the mouth and on the lips. Electrophysiological studies have revealed that its active ingredient can induce firing of mechanoreceptor fibres that typically respond to mechanical vibration. Moreover, a human behavioral study has reported that the perceived frequency of sanshool-induced tingling matches with the preferred frequency range of the tactile rapidly adapting (RA) channel, suggesting the contribution of sanshool-induced RA channel firing to its unique perceptual experience. However, since the RA channel may not be the only channel activated by sanshool, there could be a possibility that the sanshool tingling percept may be caused in whole or in part by other sensory channels. Here, by using a perceptual interference paradigm, we show that the sanshool-induced RA input indeed contributes to the human tactile processing. The absolute detection thresholds for vibrotactile input were measured with and without sanshool application on the fingertip. Sanshool significantly impaired detection of vibrations at 30 Hz (RA channel dominant frequency), but did not impair detection of higher frequency vibrations at 240 Hz (Pacinian-corpuscle (PC) channel dominant frequency) or lower frequency vibrations at 1 Hz (slowly adapting 1 (SA1) channel dominant frequency). These results show that the sanshool induces a peripheral RA channel activation that is relevant for tactile perception. This anomalous activation of RA channels may contribute to the unique tingling experience of sanshool.
Topics: Adult; Amides; Female; Fingers; Humans; Male; Mechanoreceptors; Mechanotransduction, Cellular; Pacinian Corpuscles; Spices; Touch; Touch Perception; Vibration
PubMed: 27935970
DOI: 10.1371/journal.pone.0165842