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Sensors (Basel, Switzerland) Jan 2023In order to advance engineering applications of robotics such as wearable health-monitoring devices, humanoid robots, etc., it is essential to investigate the tactile...
In order to advance engineering applications of robotics such as wearable health-monitoring devices, humanoid robots, etc., it is essential to investigate the tactile sensations of artificial haptic sensors mimicking bioinspired human cutaneous mechanoreceptors such as free nerve endings, Merkel's cells, Krause end bulbs, Meissner corpuscles, Ruffini endings, and Pacinian corpuscles. The generated receptor's potential response to extraneous stimuli, categorized as slow adaption (SA) or fast adaption (FA), is particularly significant as a typical property. The present study addressed the estimation of SA and FA by utilizing morphologically fabricated mechanoreceptors made of our proposed magnetically responsive intelligent fluid, hybrid fluid (HF), and by applying our proposed electrolytic polymerization. Electric circuit models of the mechanoreceptors were generated using experimental data on capacitance and inductance on the basis of the electric characteristics of impedance. The present results regarding equivalent firing rates based on FA and SA are consistent with the FA and SA findings of vital mechanoreceptors by biomedical analysis. The present investigative process is useful to clarify the time of response to a force on the fabricated artificial mechanoreceptor.
PubMed: 36772367
DOI: 10.3390/s23031327 -
Annals of Anatomy = Anatomischer... Jan 2020Our group had recently described human hand Pacinian corpuscles (PCs): the hand PCs are not simply arranged along the digital palmar nerves but often exhibited specific...
PURPOSE
Our group had recently described human hand Pacinian corpuscles (PCs): the hand PCs are not simply arranged along the digital palmar nerves but often exhibited specific morphologies known uncommonly. However, there is still no or few information about human foot PCs.
MATERIALS AND METHODS
We observed transverse sections of all five toes including the interdigital area obtained from 12 feet of eight fetuses at 28-33 weeks (crown-rump length 230-290mm). Serial sections were prepared for 3D reconstructions and measurement.
RESULTS
Foot PCs were characterized by (1) a dense distribution in the interdigital area in contrast to a few PCs in the distal tip of the all five toes; (2) abundant dorsal PCs including those in the nail bed and: (3) a long chain of PCs in the flexor tendon sheath of all five toes. Therefore, a distal dominance was not evident in the foot in contrast to the hand and, a tendon sheath contained much greater numbers of PCs than the hand. A tree-like or bouquet-like arrangement of PCs along a short perforating artery to the palmar digital skin was seen in the foot as we had described in the hand. The tree of foot PCs was sometimes seen laying transversely along the digital skin surface, not toward the skin.
CONCLUSION
It is still unknown that, in utero, how the PCs distribution became different between the hand and foot: it might be determined genetically in a region-specific manner.
Topics: Female; Fetus; Foot; Humans; Imaging, Three-Dimensional; Immunohistochemistry; Male; Nails; Pacinian Corpuscles; Tendons; Toes
PubMed: 31563572
DOI: 10.1016/j.aanat.2019.151421 -
Journal of Cutaneous Pathology Oct 2020Structures resembling Meissner corpuscles have been described in various nerve sheath tumors, including schwannomas and neurofibromas. When present, they are focal or...
Structures resembling Meissner corpuscles have been described in various nerve sheath tumors, including schwannomas and neurofibromas. When present, they are focal or scattered, and rarely a prominent feature of the lesion. Here, we report a case of a 39-year-old female who presented with an isolated lesion on her abdomen. Histopathologically, the tumor was almost exclusively composed of Meissner corpuscle-like structures (pseudo-meissnerian bodies). At a small edge of the tumor, there were features of a classic neurofibroma, with a mixture of Schwann cells, fibroblast-like cells, and interspersed mast cells. We propose the term "meissnerian neurofibroma" for this extremely rare variant of neurofibroma.
Topics: Adult; Diagnosis, Differential; Female; Fibroblasts; Humans; Mast Cells; Mechanoreceptors; Nerve Sheath Neoplasms; Neurilemmoma; Neurofibroma; S100 Proteins; Schwann Cells
PubMed: 32447757
DOI: 10.1111/cup.13759 -
Scientific Reports Mar 2020The function of the external ear canal in cetaceans is still under debate and its morphology is largely unknown. Immunohistochemical (IHC) analyses using antibodies...
The function of the external ear canal in cetaceans is still under debate and its morphology is largely unknown. Immunohistochemical (IHC) analyses using antibodies specific for nervous tissue (anti-S100, anti-NSE, anti-NF, and anti-PGP 9.5), together with transmission electron microscopy (TEM) and various histological techniques, were carried out to investigate the peripheral nervous system of the ear canals of several species of toothed whales and terrestrial Cetartiodactyla. This study highlights the innervation of the ear canal with the presence of lamellar corpuscles over its entire course, and their absence in all studied terrestrial mammals. Each corpuscle consisted of a central axon, surrounded by lamellae of Schwann receptor cells, surrounded by a thin cellular layer, as shown by IHC and TEM. These findings indicate that the corpuscles are mechanoreceptors that resemble the inner core of Pacinian corpuscles without capsule or outer core, and were labelled as simple lamellar corpuscles. They form part of a sensory system that may represent a unique phylogenetic feature of cetaceans, and an evolutionary adaptation to life in the marine environment. Although the exact function of the ear canal is not fully clear, we provide essential knowledge and a preliminary hypothetical deviation on its function as a unique sensory organ.
Topics: Animals; Axons; Ear Canal; Immunohistochemistry; Male; Microscopy, Electron, Transmission; Pacinian Corpuscles; Peripheral Nervous System; Phylogeny
PubMed: 32144309
DOI: 10.1038/s41598-020-61170-4 -
Sensors (Basel, Switzerland) Dec 2020It is known that humans experience a haptic illusion, such as the sensation of being pulled in a particular direction, when asymmetric vibrations are presented. A...
It is known that humans experience a haptic illusion, such as the sensation of being pulled in a particular direction, when asymmetric vibrations are presented. A pulling illusion has been used to provide a force feedback for a virtual reality (VR) system and a pedestrian navigation system, and the asymmetric vibrations can be implemented in any small non-grounded device. However, the design methodology of asymmetric vibration stimuli to induce the pulling illusion has not been fully demonstrated. Although the frequency of the asymmetric vibration is important, findings on the frequency have not been reported. In this study, we clarified the influences of the effects on the pulling illusion based on the investigation of asymmetric vibration frequency differences. Two psychophysical experiments that related to the frequency of asymmetric vibration were performed. Experiment I showed that the illusion occurs for specific vibration waveforms at 40 Hz and 75 Hz. As a result of Experiment II, the threshold was the lowest when the frequency was 40 Hz, and highest when the frequency was 110 Hz. This result supports the previous hypothesis that the Meissner corpuscles and the Ruffini endings contribute to the illusion, while the Pacinian corpuscles do not.
PubMed: 33321954
DOI: 10.3390/s20247086 -
Annals of Anatomy = Anatomischer... Feb 2024The cutaneous end organ complexes or cutaneous sensory corpuscles are specialized sensory organs associated to low-threshold mechanoreceptors. Mechano-gated proteins...
BACKGROUND
The cutaneous end organ complexes or cutaneous sensory corpuscles are specialized sensory organs associated to low-threshold mechanoreceptors. Mechano-gated proteins forming a part of ion channels have been detected in both the axon and terminal glial cells of Meissner corpuscles, a specific cutaneous end organ complex in the human glabrous skin. The main candidates to mechanotransduction in Meissner corpuscles are members of the Piezo family of cationic ion channels. PIEZO2 has been detected in the axon of these sensory structures whereas no data exists about the occurrence and cell localization of PIEZO1.
METHODS
Skin samples (n = 18) from the palmar aspect of the distal phalanx of the first and second fingers were analysed (8 female and 10 males; age range 26 to 61 26-61 years). Double immunofluorescence for PIEZO1 and PIEZO2 together with axonal or terminal glial cell markers was captured by laser confocal microscopy, and the percentage of PIEZOs positive Meissner corpuscles was evaluated.
RESULTS
MCs from human fingers showed variable morphology and degree of lobulation. Regarding the basic immunohistochemical profile, in all cases the axons were immunoreactive for neurofilament proteins, neuron specific enolase and synaptophysin, while the lamellar cells displayed strong S100P immunoreactivity. PIEZO1 was detected co-localizing with axonal markers, but never with terminal glial cell markers, in the 56% of Meissner corpuscles; weak but specific immunofluorescence was additionally detected in the epidermis, especially in basal keratinocytes. Similarly, PIEZO2 immunoreactivity was found restricted to the axon in the 85% of Meissner corpuscles. PIEZO2 positive Merkel cells were also regularly found.
CONCLUSIONS
PIEZO1 and PIEZO2 are expressed exclusively in the axon of a subpopulation of human digital Meissner corpuscles, thus suggesting that not only PIEZO2, but also PIEZO1 may be involved in the mechanotransduction from low-threshold mechanoreceptors.
Topics: Female; Humans; Male; Ion Channels; Mechanoreceptors; Mechanotransduction, Cellular; Merkel Cells; Pacinian Corpuscles; Skin; Adult; Middle Aged
PubMed: 38109982
DOI: 10.1016/j.aanat.2023.152200 -
Sensors (Basel, Switzerland) May 2023In order to advance the development of sensors fabricated with monofunctional sensation systems capable of a versatile response to tactile, thermal, gustatory,...
In order to advance the development of sensors fabricated with monofunctional sensation systems capable of a versatile response to tactile, thermal, gustatory, olfactory, and auditory sensations, mechanoreceptors fabricated as a single platform with an electric circuit require investigation. In addition, it is essential to resolve the complicated structure of the sensor. In order to realize the single platform, our proposed hybrid fluid (HF) rubber mechanoreceptors of free nerve endings, Merkel cells, Krause end bulbs, Meissner corpuscles, Ruffini endings, and Pacinian corpuscles mimicking the bio-inspired five senses are useful enough to facilitate the fabrication process for the resolution of the complicated structure. This study used electrochemical impedance spectroscopy (EIS) to elucidate the intrinsic structure of the single platform and the physical mechanisms of the firing rate such as slow adaption (SA) and fast adaption (FA), which were induced from the structure and involved the capacitance, inductance, reactance, etc. of the HF rubber mechanoreceptors. In addition, the relations among the firing rates of the various sensations were clarified. The adaption of the firing rate in the thermal sensation is the opposite of that in the tactile sensation. The firing rates in the gustation, olfaction, and auditory sensations at frequencies of less than 1 kHz have the same adaption as in the tactile sensation. The present findings are useful not only in the field of neurophysiology, to research the biochemical reactions of neurons and brain perceptions of stimuli, but also in the field of sensors, to advance salient developments in sensors mimicking bio-inspired sensations.
Topics: Smell; Rubber; Touch; Mechanoreceptors; Thermosensing
PubMed: 37430506
DOI: 10.3390/s23104593 -
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 -
Somatosensory & Motor Research Jun 2020The Pacinian Corpuscle (PC) is the most sensitive mechanoreceptor in the human body found in clusters of two or three. We extended our previous model of an isolated-PC...
The Pacinian Corpuscle (PC) is the most sensitive mechanoreceptor in the human body found in clusters of two or three. We extended our previous model of an isolated-PC to a cluster-PC focussing on relative spike delay and displacement threshold for understanding how the stimulus location is coded. In our model, two PCs with Gaussian overlapping receptive fields are arranged beneath the skin model. For a spatiotemporal stimulus (vibration), the model response is proposed to be a time-division multiplexing of responses from two PCs within the cluster. While the spike rate characteristics and pole-zero plot of cluster-PC model show similarities with the isolated-PC model, the frequency response shows ripples after 1 kHz as the distance () between the PCs increases. The stimulus location [Formula: see text] and influence the relative spike delay and the displacement threshold, but not the spike rate. The novel contributions from our model include prediction of (i) relative spike delay for various , stimulus frequency (), and , (ii) spike rate characteristics for varying , and (iii) displacement threshold curve as a function of frequency for various . Although the physiological validation of the novel predictions is impractical, we have validated the relative spike delay and the displacement threshold curves with experimental data in the literature.
Topics: Action Potentials; Humans; Models, Biological; Pacinian Corpuscles; Physical Stimulation; Spatio-Temporal Analysis; Vibration
PubMed: 32065012
DOI: 10.1080/08990220.2020.1726739 -
Somatosensory & Motor Research Mar 2024The purpose of this study was to determine the changes in the Blood Oxygen Level Dependent signal of Primary somatosensory area (S1) and Brodmann area 3 (BA3) per finger...
PURPOSE AND METHOD
The purpose of this study was to determine the changes in the Blood Oxygen Level Dependent signal of Primary somatosensory area (S1) and Brodmann area 3 (BA3) per finger and phalanx in comparison to the activation voxel when 250 Hz vibratory stimulation with high sensitivity for the Pacinian corpuscle was given to the four fingers and three phalanges.
RESULTS
The result of analyzing the activation voxel showed a significant difference for S1 per finger and phalanx, but for BA3, no significant difference was observed despite a similar trend to S1. In contrast, the activation intensity (BOLD) displayed a significant difference for S1 per finger and phalanx and for BA3, where the activation voxel had no significant variation. In addition, while the result of S1 did not indicate whether the index or the little fingers had the highest sensitivity based on the BOLD signal per finger, the result of BA3 marked the strongest BOLD signal for the little finger as a response to 250 Hz vibratory stimulation. The activation intensity per phalanx was the highest for the intermediate phalanx for S1 and BA3, which was in line with a previous study comparing the activation voxel.
CONCLUSIONS
The method based on the intensity of the nerve activation is presumed to have high sensitivity as the signal intensity is monitored within a specific, defined area. Thus, for the extraction of brain activation patterns of micro-domains, such as BA3, monitoring the BOLD signal that reflects the nerve activation intensity more sensitively is likely to be advantageous.
Topics: Somatosensory Cortex; Magnetic Resonance Imaging; Fingers; Brain Mapping
PubMed: 36721377
DOI: 10.1080/08990220.2023.2173165