The structure and function of Pacinian corpuscles: a review. The development of Pacinian corpuscles. Schwaller, F. Wende, H. The transcription factor c-Maf controls touch receptor development and function. Alvarez-Buylla, R.
Local responses in Pacinian corpuscles. Brisben, A. Detection of vibration transmitted through an object grasped in the hand. Detection thresholds for stimuli in humans and monkeys: comparison with threshold events in mechanoreceptive afferent nerve fibers innervating the monkey hand.
Johnson, K. The roles and functions of cutaneous mechanoreceptors. Luo, W. Molecular identification of rapidly adapting mechanoreceptors and their developmental dependence on ret signaling. Neuron 64 , — Pease, D. Electron microscopy of the Pacinian corpuscle. Vega, J. The inner-core, outer-core and capsule cells of the human Pacinian corpuscles: an immunohistochemical study.
Spencer, P. An ultrastructural study of the inner core of the Pacinian corpuscle. The Meissner and Pacinian sensory corpuscles revisited new data from the last decade. Endoneurial-CD34 positive cells define an intermediate layer in human digital Pacinian corpuscles. Loewenstein, W. Excitation inactivation a receptor membrane. Components of receptor adaptation in a Pacinian corpuscle.
Nikolaev, Y. Lamellar cells in Pacinian and Meissner corpuscles are touch sensors. Quindlen, J. A multiphysics model of the Pacinian corpuscle. Pawson, L. Wagner, R. Uber das Vorhandensein bisher unbekannter eigenthumlicher Tastkorperchen corpuscula tactus in den Gefuhlswarzchen der menschlichen Haut und uber die Endausbreitung sensitiver Nerven. LaMotte, R. Tactile detection of a dot on a smooth surface: Peripheral neural events.
Lindblom, U. Properties of touch receptors in distal glabrous skin of the monkey. Srinivasan, M. Tactile detection of slip: surface microgeometry and peripheral neural codes. Freeman, A. A model accounting for effects of vibratory amplitude on responses of cutaneous mechanoreceptors in macaque monkey. Tactile functions of mechanoreceptive afferents innervating the hand. Development of Meissner corpuscle of mouse toe pad.
Hashimoto, K. Fine structure of the Meissner corpuscle of human palmar skin. Takahashi-Iwanaga, H. The three-dimensional microanatomy of Meissner corpuscles in monkey palmar skin. Cuana, N. The fine structure of the digital corpuscle of the mouse toe pad, with special reference to nerve fibers. Walcher, J. Specialized mechanoreceptor systems in rodent glabrous skin.
Heidenreich, M. Chiang, L. Laminin coordinates mechanotransduction and growth cone bifurcation in sensory neurons. Hu, J. Evidence for a protein tether involved in somatic touch. EMBO J. Wu, H. Morphologic diversity of cutaneous sensory afferents revealed by genetically directed sparse labeling. Elife 1 , e Bourane, S. Low-threshold mechanoreceptor subtypes selectively express MafA and are specified by Ret signaling.
Cutaneous mechanoreceptors with afferent C fibres. The low-threshold calcium channel Cav3. Cell Rep. Wang, R. The Cav3. Zotterman, Y. Touch, pain and tickling: an electro-physiological investigation on cutaneous sensory nerves. A system of unmyelinated afferents for innocuous mechanoreception in the human skin. Abraira, V. The cellular and synaptic architecture of the mechanosensory dorsal horn. Fine structure of perifollicular nerve endings in human hair.
The structure and organization of lanceolate mechanosensory complexes at mouse hair follicles. Kaidoh, T. Intercellular junctions between palisade nerve endings and outer root sheath cells of rat vellus hairs. N-cadherin expression in palisade nerve endings of rat vellus hairs. Three-dimensional microanatomy of longitudinal lanceolate endings in rat vibrissae. TrkC kinase expression in distinct subsets of cutaneous trigeminal innervation and nonneuronal cells.
Chambers, M. The structure and function of the slowly adapting type II mechanoreceptor in hairy skin. Wellnitz, S. The regularity of sustained firing reveals two populations of slowly adapting touch receptors in mouse hairy skin. Slowly-adapting cutaneous mechanoreceptors. Merzenich, M. The sense of flutter-vibration evoked by stimulation of the hairy skin of primates: comparison of human sensory capacity with the responses of mechanoreceptive afferents innervating the hairy skin of monkeys.
Edin, B. Quantitative analysis of static strain sensitivity in human mechanoreceptors from hairy skin. Fleming, M. The ultrastructure of sensory nerve endings in the human knee joint capsule. Rice, F. Innervation of the digit on the forepaw of the raccoon. Byers, M. Sensory innervation of periodontal ligament of rat molars consists of unencapsulated Ruffini-like mechanoreceptors and free nerve endings.
Rasmusson, D. Sensory innervation of the raccoon forepaw: 2. Response properties and classification of slowly adapting fibers. Li, C. Somatosensory neuron types identified by high-coverage single-cell RNA-sequencing and functional heterogeneity. Cell Res. Nguyen, M. Diversity amongst trigeminal neurons revealed by high throughput single cell sequencing. Abdo, H. Specialized cutaneous Schwann cells initiate pain sensation.
Moehring, F. Winkelmann, R. The mucocutaneous end-organ: the primary organized sensory ending in human skin. AMA Arch. Yamada, K. On the sensory nerve terminations in clitoris in human adult. Tohoku J. Gairns, F. The sensory nerve endings of the human palate. Cathcart, E. The innervation of the human quiescent nipple, with notes on pigmentation, erection, and hyperneury. Ohmori, D. Krause, W. Uber die Nervenendigung in den Geschlechtsorganen. XXVII , 86—88 McNeilly, A. Physiology of lactation.
Katz, D. The world of touch. Translated by Lester E. Routledge, Rieke, F. Naturalistic stimuli increase the rate and efficiency of information transmission by primary auditory afferents. B Biol. Lewicki, M. Efficient coding of natural sounds. Leiser, S. Responses of trigeminal ganglion neurons during natural whisking behaviors in the awake rat.
Neuron 53 , — Blake, D. Neural coding mechanisms in tactile pattern recognition: The relative contributions of slowly and rapidly adapting mechanoreceptors to perceived roughness. Macefield, V. With a pair of dividers like those used in mechanical drawing, determine in a blindfolded subject the minimum separation of the points that produces two separate touch sensations.
The ability to discriminate the two points is far better on the fingertips than on, say, the small of the back. The density of touch receptors is also reflected in the amount of somatosensory cortex in the brain assigned to that region of the body. Proprioception is our "body sense". It enables us to unconsciously monitor the position of our body.
It depends on receptors in the muscles, tendons, and joints. If you have ever tried to walk after one of your legs has "gone to sleep," you will have some appreciation of how difficult coordinated muscular activity would be without proprioception. Pacinian corpuscles are pressure receptors. They are located in the skin and also in various internal organs. Each is connected to a sensory neuron.
Because of its relatively large size, a single Pacinian corpuscle can be isolated and its properties studied. Mechanical pressure of varying strength and frequency is applied to the corpuscle by the stylus. The electrical activity is detected by electrodes attached to the preparation.
Deforming the corpuscle creates a generator potential in the sensory neuron arising within it. This is a graded response: the greater the deformation, the greater the generator potential. If the generator potential reaches threshold, a volley of action potentials also called nerve impulses are triggered at the first node of Ranvier of the sensory neuron.
Once threshold is reached, the magnitude of the stimulus is encoded in the frequency of impulses generated in the neuron. So the more massive or rapid the deformation of a single corpuscle, the higher the frequency of nerve impulses generated in its neuron.
When pressure is first applied to the corpuscle, it initiates a volley of impulses in its sensory neuron. However, with continuous pressure, the frequency of action potentials decreases quickly and soon stops.
This is the phenomenon of adaptation. The mechanoreceptors are activated, the signal is conveyed, and then processed. Some types of mechanoreceptors have large receptive fields, while others have smaller ones. Large receptive fields allow the cell to detect changes over a wider area, but lead to a less-precise perception.
Touch receptors are denser in glabrous skin the type found on human fingertips and lips, for example , which is typically more sensitive and is thicker than hairy skin 4 to 5 mm versus 2 to 3 mm. Thus, the fingers, which require the ability to detect fine detail, have many, densely-packed up to per cubic cm mechanoreceptors with small receptive fields around 10 square mm , while the back and legs, for example, have fewer receptors with large receptive fields.
In general, these neurons have relatively large receptive fields much larger than those of dorsal root ganglion cells. However, the neurons are able to discriminate fine detail due to patterns of excitation and inhibition relative to the field, which leads to spatial resolution.
The relative density of pressure receptors in different locations on the body can be demonstrated experimentally using a two-point discrimination test. The subject reports if they feel one point or two points. If the two points are felt as one point, it can be inferred that the two points are both in the receptive field of a single sensory receptor. If two points are felt as two separate points, each is in the receptive field of two separate sensory receptors.
The points could then be moved closer and re-tested until the subject reports feeling only one point. The size of the receptive field of a single receptor could be estimated from that distance. Thermoreception is the process of determining temperature by comparing the activation of different thermoreceptors in the brain. Describe the various types of receptors used for thermoreception: Krause end bulbs, Ruffini endings, free nerve endings.
Thermoception or thermoreception is the sense by which an organism perceives temperatures. The details of how temperature receptors work are still being investigated. Mammals have at least two types of sensors: those that detect heat i. A thermoreceptor is a sensory receptor or, more accurately, the receptive portion of a sensory neuron that codes absolute and relative changes in temperature, primarily within the innocuous range.
The adequate stimulus for a warm receptor is warming, which results in an increase in their action potential discharge rate; cooling results in a decrease in warm receptor discharge rate. For cold receptors, their firing rate increases during cooling and decreases during warming. The types of receptors capable of detecting changes in temperature can vary. Some of the receptors that exhibit the ability to detect changes in temperature include Krause end bulbs and Ruffini endings.
Krause end bulbs are defined by cylindrical or oval bodies consisting of a capsule that is formed by the expansion of the connective-tissue sheath, containing an axis-cylinder core. End-bulbs are found in the conjunctiva of the eye, in the mucous membrane of the lips and tongue, and in the epineurium of nerve trunks. They are also found in the penis and the clitoris; hence, the name of genital corpuscles.
In these locations, they have a mulberry-like appearance, being constricted by connective-tissue septa into two to six knob-like masses. Krause end bulb : A drawing of a Krause end bulb receptor which can detect cold.
The Ruffini endings, enlarged dendritic endings with elongated capsules, can act as thermoreceptors. This spindle-shaped receptor is sensitive to skin stretch, contributing to the kinesthetic sense of and control of finger position and movement. Ruffini corpuscles respond to sustained pressure and show very little adaptation. Ruffinian endings are located in the deep layers of the skin where they register mechanical deformation within joints as well as continuous pressure states.
They also act as thermoreceptors that respond for an extended period; in case of deep burn, there will be no pain as these receptors will be burned off. Ruffini endings : A drawing of a Ruffini ending receptor which can detect warmth.
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