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Neurogastroenterology and Motility Dec 2019Vagally dependent gastric functions, including motility, tone, compliance, and emptying rate, play an important role in the regulation of food intake and satiation.... (Review)
Review
Vagally dependent gastric functions, including motility, tone, compliance, and emptying rate, play an important role in the regulation of food intake and satiation. Vagal afferent fibers relay sensory information from the stomach, including meal-related information, centrally and initiate co-ordinated autonomic efferent responses that regulate upper gastrointestinal responses. The purpose of this mini-review is to highlight several recent studies which have uncovered the remarkable degree of neuroplasticity within gastric mechanosensitive vagal afferents and the recent study by Li et al, in this issue of Neurogastroenterology and Motility, who show that the mechanosensitivity of gastric vagal afferents is dysregulated in a murine model of chronic stress. The authors demonstrate that both gastric mucosal and tension afferents are hypersensitive following chronic stress, and responses to mucosal stroking and muscle stretch are enhanced significantly. As gastric distension and volumetric signaling is important in satiety signaling and meal termination, this may provide a mechanistic basis for the gastric hypersensitivity associated with stress-associated clinical problems such as functional dyspepsia.
Topics: Afferent Pathways; Animals; Dyspepsia; Eating; Female; Gastric Mucosa; Gastrointestinal Diseases; Humans; Male; Mechanoreceptors; Mice; Mice, Inbred C57BL; Models, Animal; Neuronal Plasticity; Satiety Response; Sex Characteristics; Stress, Psychological; Vagus Nerve
PubMed: 31736236
DOI: 10.1111/nmo.13758 -
Sheng Li Xue Bao : [Acta Physiologica... Dec 2022Muscle spindle is the key proprioceptor in skeletal muscles and plays important roles in many physiological activities, such as maintaining posture, regulating movement... (Review)
Review
Muscle spindle is the key proprioceptor in skeletal muscles and plays important roles in many physiological activities, such as maintaining posture, regulating movement and controlling speed variation. It has significant clinical relevance and is emerging as a promising therapeutic target for the treatment of motor functional impairment and metabolic diseases. In this review, we summarized muscle spindle distribution and the mechanism of mechanical signal transmission, and reviewed the research progress on morphological and structural characteristics of muscle spindles.
Topics: Muscle Spindles; Muscle, Skeletal; Clinical Relevance
PubMed: 36594392
DOI: No ID Found -
ELife Feb 2024Two calcium-binding proteins, CaBP1 and CaBP2, cooperate to keep calcium channels in the hair cells of the inner ear open.
Two calcium-binding proteins, CaBP1 and CaBP2, cooperate to keep calcium channels in the hair cells of the inner ear open.
Topics: Calcium; Hair Cells, Auditory; Calcium Channels; Calcium, Dietary; Hair Cells, Auditory, Inner; Calcium-Binding Proteins
PubMed: 38334748
DOI: 10.7554/eLife.96139 -
Frontiers in Immunology 2021The gateway reflex explains how autoreactive CD4+ T cells cause inflammation in tissues that have blood-barriers, such as the central nervous system and retina. It... (Review)
Review
The gateway reflex explains how autoreactive CD4+ T cells cause inflammation in tissues that have blood-barriers, such as the central nervous system and retina. It depends on neural activations in response to specific external stimuli, such as gravity, pain, stress, and light, which lead to the secretion of noradrenaline at specific vessels in the tissues. Noradrenaline activates NFkB at these vessels, followed by an increase of chemokine expression as well as a reduction of tight junction molecules to accumulate autoreactive CD4+ T cells, which breach blood-barriers. Transient receptor potential vanilloid 1 (TRPV1) molecules on sensory neurons are critical for the gateway reflex, indicating the importance of mechano-sensing. In this review, we overview the gateway reflex with a special interest in mechanosensory transduction (mechanotransduction).
Topics: Animals; Blood-Brain Barrier; CD4-Positive T-Lymphocytes; Disease Models, Animal; Endothelial Cells; Humans; Mechanoreceptors; Mechanotransduction, Cellular; NF-kappa B; Neuroimmunomodulation; Neuroinflammatory Diseases; Norepinephrine; Signal Transduction; TRPV Cation Channels
PubMed: 35003096
DOI: 10.3389/fimmu.2021.780451 -
Cell Oct 2021Mammals use glabrous (hairless) skin of their hands and feet to navigate and manipulate their environment. Cortical maps of the body surface across species contain...
Mammals use glabrous (hairless) skin of their hands and feet to navigate and manipulate their environment. Cortical maps of the body surface across species contain disproportionately large numbers of neurons dedicated to glabrous skin sensation, in part reflecting a higher density of mechanoreceptors that innervate these skin regions. Here, we find that disproportionate representation of glabrous skin emerges over postnatal development at the first synapse between peripheral mechanoreceptors and their central targets in the brainstem. Mechanoreceptor synapses undergo developmental refinement that depends on proximity of their terminals to glabrous skin, such that those innervating glabrous skin make synaptic connections that expand their central representation. In mice incapable of sensing gentle touch, mechanoreceptors innervating glabrous skin still make more powerful synapses in the brainstem. We propose that the skin region a mechanoreceptor innervates controls the developmental refinement of its central synapses to shape the representation of touch in the brain.
Topics: Action Potentials; Animals; Animals, Newborn; Axons; Brain Stem; Ion Channels; Mechanoreceptors; Mice, Knockout; Neurons; Optical Imaging; Optogenetics; Skin; Synapses; Touch Perception; Mice
PubMed: 34637701
DOI: 10.1016/j.cell.2021.09.023 -
Trends in Neurosciences Dec 2023Proprioception, the sense of body position in space, has a critical role in the control of posture and movement. Aside from skin and joint receptors, the main sources of... (Review)
Review
Proprioception, the sense of body position in space, has a critical role in the control of posture and movement. Aside from skin and joint receptors, the main sources of proprioceptive information in tetrapods are mechanoreceptive end organs in skeletal muscle: muscle spindles (MSs) and Golgi tendon organs (GTOs). The sensory neurons that innervate these receptors are divided into subtypes that detect discrete aspects of sensory information from muscles with different biomechanical functions. Despite the importance of proprioceptive neurons in motor control, the developmental mechanisms that control the acquisition of their distinct functional properties and positional identity are not yet clear. In this review, we discuss recent findings on the development of mouse proprioceptor subtypes and challenges in defining them at the molecular and functional level.
Topics: Mice; Animals; Sensory Receptor Cells; Mechanoreceptors; Muscle Spindles; Muscle, Skeletal; Proprioception
PubMed: 37858440
DOI: 10.1016/j.tins.2023.09.008 -
Experimental Physiology Jan 2024Proprioception is the sense that lets us perceive the location, movement and action of the body parts. The proprioceptive apparatus includes specialized sense organs... (Review)
Review
Proprioception is the sense that lets us perceive the location, movement and action of the body parts. The proprioceptive apparatus includes specialized sense organs (proprioceptors) which are embedded in the skeletal muscles. The eyeballs are moved by six pairs of eye muscles and binocular vision depends on fine-tuned coordination of the optical axes of both eyes. Although experimental studies indicate that the brain has access to eye position information, both classical proprioceptors (muscle spindles and Golgi tendon organ) are absent in the extraocular muscles of most mammalian species. This paradox of monitoring extraocular muscle activity in the absence of typical proprioceptors seemed to be resolved when a particular nerve specialization (the palisade ending) was detected in the extraocular muscles of mammals. In fact, for decades there was consensus that palisade endings were sensory structures that provide eye position information. The sensory function was called into question when recent studies revealed the molecular phenotype and the origin of palisade endings. Today we are faced with the fact that palisade endings exhibit sensory as well as motor features. This review aims to evaluate the literature on extraocular muscle proprioceptors and palisade endings and to reconsider current knowledge of their structure and function.
Topics: Animals; Oculomotor Muscles; Sensory Receptor Cells; Mechanoreceptors; Proprioception; Muscle Spindles; Mammals
PubMed: 36869596
DOI: 10.1113/EP090765 -
Hypertension (Dallas, Tex. : 1979) Jan 2022
Topics: Baroreflex; Blood Pressure; Pressoreceptors
PubMed: 34878899
DOI: 10.1161/HYPERTENSIONAHA.121.18372 -
Cell Nov 2022The encoding of touch in the spinal cord dorsal horn (DH) and its influence on tactile representations in the brain are poorly understood. Using a range of mechanical...
The encoding of touch in the spinal cord dorsal horn (DH) and its influence on tactile representations in the brain are poorly understood. Using a range of mechanical stimuli applied to the skin, large-scale in vivo electrophysiological recordings, and genetic manipulations, here we show that neurons in the mouse spinal cord DH receive convergent inputs from both low- and high-threshold mechanoreceptor subtypes and exhibit one of six functionally distinct mechanical response profiles. Genetic disruption of DH feedforward or feedback inhibitory motifs, comprised of interneurons with distinct mechanical response profiles, revealed an extensively interconnected DH network that enables dynamic, flexible tuning of postsynaptic dorsal column (PSDC) output neurons and dictates how neurons in the primary somatosensory cortex respond to touch. Thus, mechanoreceptor subtype convergence and non-linear transformations at the earliest stage of the somatosensory hierarchy shape how touch of the skin is represented in the brain.
Topics: Animals; Mice; Spinal Cord Dorsal Horn; Mechanoreceptors; Touch; Interneurons; Brain; Spinal Cord
PubMed: 36334588
DOI: 10.1016/j.cell.2022.10.012 -
Cell Reports Oct 2019Recent rapid progress in the field of mechanobiology has been driven by novel emerging tools and methodologies and growing interest from different scientific... (Review)
Review
Recent rapid progress in the field of mechanobiology has been driven by novel emerging tools and methodologies and growing interest from different scientific disciplines. Specific progress has been made toward understanding how cell mechanics is linked to intracellular signaling and the regulation of gene expression in response to a variety of mechanical stimuli. There is a direct link between the mechanoreceptors at the cell surface and intracellular biochemical signaling, which in turn controls downstream effector molecules. Among the mechanoreceptors in the cell membrane, mechanosensitive (MS) ion channels are essential for the ultra-rapid (millisecond) transduction of mechanical stimuli into biologically relevant signals. The three decades of research on mechanosensitive channels resulted in the formulation of two basic principles of mechanosensitive channel gating: force-from-lipids and force-from-filament. In this review, we revisit the biophysical principles that underlie the innate force-sensing ability of mechanosensitive channels as contributors to the force-dependent evolution of life forms.
Topics: Animals; Biophysics; Cell Membrane; Humans; Ion Channels; Mechanoreceptors; Mechanotransduction, Cellular; Signal Transduction
PubMed: 31577940
DOI: 10.1016/j.celrep.2019.08.075