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Neuron Oct 2023Across mammalian skin, structurally complex and diverse mechanosensory end organs respond to mechanical stimuli and enable our perception of dynamic, light touch. How...
Across mammalian skin, structurally complex and diverse mechanosensory end organs respond to mechanical stimuli and enable our perception of dynamic, light touch. How forces act on morphologically dissimilar mechanosensory end organs of the skin to gate the requisite mechanotransduction channel Piezo2 and excite mechanosensory neurons is not understood. Here, we report high-resolution reconstructions of the hair follicle lanceolate complex, Meissner corpuscle, and Pacinian corpuscle and the subcellular distribution of Piezo2 within them. Across all three end organs, Piezo2 is restricted to the sensory axon membrane, including axon protrusions that extend from the axon body. These protrusions, which are numerous and elaborate extensively within the end organs, tether the axon to resident non-neuronal cells via adherens junctions. These findings support a unified model for dynamic touch in which mechanical stimuli stretch hundreds to thousands of axon protrusions across an end organ, opening proximal, axonal Piezo2 channels and exciting the neuron.
Topics: Animals; Merkel Cells; Mechanotransduction, Cellular; Imaging, Three-Dimensional; Ion Channels; Mechanoreceptors; Mammals
PubMed: 37725982
DOI: 10.1016/j.neuron.2023.08.023 -
Radiology Case Reports Sep 2023Pacinian corpuscles are mechanoreceptors frequently found between the dermis and subcutaneous tissues of the hands and feet. They are responsible for sensitivity to...
Pacinian corpuscles are mechanoreceptors frequently found between the dermis and subcutaneous tissues of the hands and feet. They are responsible for sensitivity to vibration and pressure. Pacinian corpuscle hyperplasia is a rare cause of induration in the palms of the hands or the soles of the feet, often of unknown origin or occasionally related to neurofibromatosis. It can be characterized by magnetic resonance imaging and is included in the differential diagnosis of anechoic lesions on high-resolution soft tissue ultrasound. The definitive diagnosis is made through histopathologic examination. In this case report, we present the findings of a 29-year-old patient who presented with painful nodules on the palms of both hands, with typical findings on ultrasound and magnetic resonance imaging indicative of Pacinian corpuscle hyperplasia. We also discuss the imaging findings and the differential diagnosis through a non-systematic review. Pacinian corpuscle hyperplasia is a rare condition that can be readily identified by high-resolution ultrasound and magnetic resonance imaging, and it should be considered in the differential diagnosis of hand nodules.
PubMed: 37483376
DOI: 10.1016/j.radcr.2023.06.046 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2024The objective of this study was to analyze the proprioceptive innervation of human lips, especially of the orbicularis oris muscle, since it is classically accepted that...
The objective of this study was to analyze the proprioceptive innervation of human lips, especially of the orbicularis oris muscle, since it is classically accepted that facial muscles lack typical proprioceptors, that is, muscle spindles, but recently this has been doubted. Upper and lower human lips (n = 5) from non-embalmed frozen cadavers were immunostained for detection of S100 protein (to identify nerves and sensory nerve formations), myosin heavy chain (to label muscle fibers within muscle spindles), and the mechano-gated ion channel PIEZO2. No muscle spindles were found, but there was a high density of sensory nerve formations, which were morphologically heterogeneous, and in some cases resemble Ruffini-like and Pacinian sensory corpuscles. The axons of these sensory formations displayed immunoreactivity for PIEZO2. Human lip muscles lack typical proprioceptors but possess a dense sensory innervation which can serve the lip proprioception.
Topics: Humans; Lip; Proprioception; Sensory Receptor Cells; Facial Muscles; Pacinian Corpuscles
PubMed: 37712912
DOI: 10.1002/ar.25324 -
BioRxiv : the Preprint Server For... Apr 2024Vibrations are ubiquitous in nature, shaping behavior across the animal kingdom. For mammals, mechanical vibrations acting on the body are detected by mechanoreceptors...
Vibrations are ubiquitous in nature, shaping behavior across the animal kingdom. For mammals, mechanical vibrations acting on the body are detected by mechanoreceptors of the skin and deep tissues and processed by the somatosensory system, while sound waves traveling through air are captured by the cochlea and encoded in the auditory system. Here, we report that mechanical vibrations detected by the body's Pacinian corpuscle neurons, which are unique in their ability to entrain to high frequency (40-1000 Hz) environmental vibrations, are prominently encoded by neurons in the lateral cortex of the inferior colliculus (LCIC) of the midbrain. Remarkably, most LCIC neurons receive convergent Pacinian and auditory input and respond more strongly to coincident tactile-auditory stimulation than to either modality alone. Moreover, the LCIC is required for behavioral responses to high frequency mechanical vibrations. Thus, environmental vibrations captured by Pacinian corpuscles are encoded in the auditory midbrain to mediate behavior.
PubMed: 38496510
DOI: 10.1101/2024.03.08.584077 -
BioRxiv : the Preprint Server For... Nov 2023Pacinian corpuscle neurons are specialized low-threshold mechanoreceptors (LTMRs) that are tuned to detect high-frequency vibration (~40-2000 Hz), however it is unclear...
Pacinian corpuscle neurons are specialized low-threshold mechanoreceptors (LTMRs) that are tuned to detect high-frequency vibration (~40-2000 Hz), however it is unclear how Pacinians and other LTMRs encode mechanical forces encountered during naturalistic behavior. Here, we developed methods to record LTMRs in awake, freely moving mice. We find that Pacinians, but not other LTMRs, encode subtle vibrations of surfaces encountered by the animal, including low-amplitude vibrations initiated over two meters away. Strikingly, Pacinians are also highly active during a wide variety of natural behaviors, including walking, grooming, digging, and climbing. Pacinians in the hindlimb are sensitive enough to be activated by forelimb- or upper-body-dominant behaviors. Finally, we find that Pacinian LTMRs have diverse tuning and sensitivity. Our findings suggest a Pacinian population code for the representation of vibro-tactile features generated by self-initiated movements and low-amplitude environmental vibrations emanating from distant locations.
PubMed: 37745531
DOI: 10.1101/2023.09.11.557225 -
Pediatric Dermatology 2023We present a rare case of Pacinian corpuscle hyperplasia (PCH) presenting with typical finger pain in a 6-year-old girl. As appendages in children are smaller than those...
We present a rare case of Pacinian corpuscle hyperplasia (PCH) presenting with typical finger pain in a 6-year-old girl. As appendages in children are smaller than those in adults, diagnostic criteria are needed for pathological confirmation of PCH in pediatric patients.
Topics: Adult; Female; Humans; Child; Pacinian Corpuscles; Hyperplasia; Pain
PubMed: 37194374
DOI: 10.1111/pde.15349