Tactile Organs Research Articles

A helping hand: roles for accessory cells in the sense of touch across species.

During touch, mechanical forces are converted into electrochemical signals by tactile organs made of neurons, accessory cells, and their shared extracellular spaces. Accessory cells, including Merkel cells, keratinocytes, lamellar cells, and glia, play an important role in the sensation of touch. In some cases, these cells are intrinsically mechanosensitive; however, other roles include the release of chemical messengers, the chemical modification of spaces that are shared with neurons, and the tuning of neural sensitivity by direct physical contact. Despite great progress in the last decade, the precise roles of these cells in the sense of touch remains unclear. Here we review the known and hypothesized contributions of several accessory cells to touch by incorporating research from multiple organisms including C. elegans, D. melanogaster, mammals, avian models, and plants. Several broad parallels are identified including the regulation of extracellular ions and the release of neuromodulators by accessory cells, as well as the emerging potential physical contact between accessory cells and sensory neurons via tethers. Our broader perspective incorporates the importance of accessory cells to the understanding of human touch and pain, as well as to animal touch and its molecular underpinnings, which are underrepresented among the animal welfare literature. A greater understanding of touch, which must include a role for accessory cells, is also relevant to emergent technical applications including prosthetics, virtual reality, and robotics.

Architecture of vibrissae in eight rodent species of Ctenohystrica (Rodentia): A comparative SEM study

Our study was conducted within the framework of comparative functional morphology of mammalian skin (Sokolov 1982) and “Trichomorphology” (Hausmann 1930; 1944; Teerink 1991) focusing in particular on specialized tactile organs such as whiskers (vibrissae). The architecture of vibrissae was studied for the first time using SEM in the relict rodent Laonastes aenigmamus and in some other representatives of the clade Ctenohystrica (Rodentia): Ctenodactylus gundi, Pectinator spekei, Proechimys guyannensis, Echimys sp., Trichomys apereoides, Chinchilla lanigera, and Octodon degus with the aim to identify the specific characters for each species. The vibrissal architecture is specific and polymorphic: the rod shape and structure of the medulla show differences between species of different genera and differ from those of guard hairs and spines of the same species. In L. aenigmamus, the vibrissal medulla is peculiar in its internal structure, which, together with the structure of guard hairs in this species, confirms its phylogenetically distinct position within Ctenohystrica. For the compared species, the complex medulla is with variously arranged systems of keratinized septa and different degrees of development of air spaces between them (ranging from unstructured and irregular to uni- or biserial ladder-like, cellated or pyramidal). The vibrissae have a non-specialized cuticle serving mostly for protection during tactile contacts, which distinguishes it from the diverse and multifunctional cuticle of guard hairs, spines, and quills. The tactile function of vibrissae is corroborated by the presence of scuff marks, scratches and even cuticle loss at the tip and on the ventral side of the rod, a thickened dense cortex and a poorly developed medullar layer but diverse its internal architecture, which provides only a very limited thermal protection, unlike that of the hair pelage. The SEM study of vibrissal architecture is a promising line of research, because a better knowledge of vibrissae may contribute to the biology and biomimetics.

A REVIEW ON HAST AND PARVSANDHI (PALM AND PHALANGEAL JOINTS): AN AYURVEDIC AND MODERN PERSPECTIVE

Ayurveda is called the science of life. It teaches us not only to deal with disease but also how to improve and maintain health. Along with modern anatomy, terms like marma, kurcha, and asthisamghat gave precise information about sharir rachana. The knowledge about the structural part of hast and parv pradesh helps the treatment. The human body is designed for grasping, precise movements and for serving as a tactile organ. There is a big area in the brain's motor cortex for muscles. Sandhi is formed by more than one bone, ligament and other structures. They are essential for locomotion and various movements of the body. There are two hundred and ten sandhi’s in body, and they play various movements. Small sandhi is called khuda sandhi. They are fifteen in number, according to Acharya Sushruta.

Tactile Neuromorphic System: Convergence of Triboelectric Polymer Sensor and Ferroelectric Polymer Synapse.

Sensory neuromorphic systems are a promising technology, because they can replicate the way the human peripheral nervous system processes signals from the five sensory organs. Despite this potential, there are limited studies on how to implement these systems on a hardware neural network platform. In our research, we propose a tactile neuromorphic system that uses a poly(dimethylsiloxane) (PDMS)-based triboelectric sensor and a molybdenum disulfide (MoS2)/poly(vinylidene fluoride-trifluoro ethylene) (P(VDF-TrFE)) heterostructure-based ferroelectric synapse. The triboelectric sensor mimics a human tactile organ by converting tactile stimuli into electrical signals in real time. The ferroelectric synapse we developed demonstrates exceptional long-term potentiation/depression characteristics with a maximum dynamic range of 78 and a symmetrical value of 4.7. To assess the practicality of our proposed system, we conducted training and recognition simulations using Morse code alphabets and MNIST handwritten digits. The maximum recognition rate that we achieved was 96.17%.

Young Women and Disgust in Contemporary Norwegian Comics: A Close Reading of Ane Barstad Solvang's Frykt & medlidenhet

Young Women and Disgust in Contemporary Norwegian Comics: A Close Reading of Ane Barstad Solvang's <i>Frykt</i> &amp; <i>medlidenhet</i>

Whisker trimming induces anti-anxiety like status via activation of dorsomedial hypothalamus nucleus in mice

Whiskers are highly developed tactile organs in mice. Here, we showed that mice with whisker trimming had a decreased anxiety behavior and activation of dorsomedial hypothalamus compared to control mice. Inhibition or damage of dorsomedial hypothalamus reversed the decrease of anxiety level induced by whisker trimming. These results expand the role of whiskers in regulating mouse behaviors to anxiety and suggest a novel function of dorsomedial hypothalamus. These findings indicate importance of normal sensory functions in modulating animal behavior.

Lamellar cells in Pacinian and Meissner corpuscles are touch sensors.

The skin covering the human palm and other specialized tactile organs contains a high density of mechanosensory corpuscles tuned to detect transient pressure and vibration. These corpuscles comprise a sensory afferent neuron surrounded by lamellar cells. The neuronal afferent is thought to be the mechanical sensor, whereas the function of lamellar cells is unknown. We show that lamellar cells within Meissner and Pacinian corpuscles detect tactile stimuli. We develop a preparation of bill skin from tactile-specialist ducks that permits electrophysiological recordings from lamellar cells and demonstrate that they contain mechanically gated ion channels. We show that lamellar cells from Meissner corpuscles generate mechanically evoked action potentials using R-type voltage-gated calcium channels. These findings provide the first evidence for R-type channel-dependent action potentials in non-neuronal cells and demonstrate that lamellar cells actively detect touch. We propose that Meissner and Pacinian corpuscles use neuronal and non-neuronal mechanoreception to detect mechanical signals.

Selective impairment of slowly adapting type 1 mechanoreceptors in mice following vincristine treatment

Loss of the sense of touch in fingertips and toes is one of the earliest sensory dysfunctions in patients receiving chemotherapy with anti-cancer drugs such as vincristine. However, mechanisms underlying this chemotherapy-induced sensory dysfunction is incompletely understood. Whisker hair follicles are tactile organs in non-primate mammals which are functionally equivalent to human fingertips. Here we used mouse whisker hair follicles as a model system and applied the pressure-clamped single-fiber recording technique to explore how vincristine treatment affect mechanoreceptors in whisker hair follicles. We showed that in vivo treatment of mice with vincristine impaired whisker tactile behavioral responses. The pressure-clamped single-fiber recordings made from whisker hair follicle afferent nerves showed that mechanical stimulations evoked three types of mechanical responses, rapidly adapting response (RA), slowly adapting type 1 response (SA1) and slowly adapting type 2 response (SA2). Vincristine treatment significantly reduced SA1 responses but did not significantly affect RA and SA2 responses. Our findings suggest that SA1 mechanoreceptors were selectively impaired by vincristine leading to the impairment of in vivo whisker tactile behavioral responses.

Tools of the trade: MicroCT reveals native structure and functional morphology of organs that drive caterpillar\u2013ant interactions

Caterpillars of many lycaenid butterflies are tended by ants that offer protection from predators and parasitoids. Specialized structures such as glands, ciliary organs and chitinous ornamentation in caterpillars play key roles in the underlying tactile, acoustic, and chemical communication between caterpillars and ants. Although the ecological, evolutionary, and behavioural aspects of these interactions are well studied, the mechanisms (i.e., the functional morphology) that drive the specialized interactive organs are poorly characterized. We used advanced X-ray microtomography (MicroCT) to delineate internal, native morphology of specialized larval dew patches, nectar glands, and tactile ciliary organs that mediate interactions between Crematogaster ants and caterpillars of the obligate myrmecophilous Apharitis lilacinus butterfly. Our non-destructive MicroCT analysis provided novel 3-D insights into the native structure and positions of these specialized organs in unmatched detail. This analysis also suggested a functional relationship between organ structures and surrounding muscles and nervation that operate the glands and tactile organs, including a ‘lasso bag’ control mechanism for dew patches and muscle control for other organs. This provided a holistic understanding of the organs that drive very close caterpillar–ant interactions. Our MicroCT analysis opens a door for similar structural and functional analysis of adaptive insect morphology.

The importance of the tactile hairs in domestic dogs and the problem of trimming these from an animal welfare perspective

The vibrissae are part of a tactile sensory organ in the facial area of the domestic dog. Each of the stiff, long tactile hairs belongs to its own, sensitively innervated, specialized hair follicle. Its structure is very similar to a cat's whiskers. The authors found no scientific evidence of this organ being underdeveloped or regressed in the domestic dog. The importance of tactile hairs has not yet been scientifically proven for the domestic dog, however, it is evident that dogs react sensitively to the touch of their vibrissae and that these hairs fulfill protective functions including the protection of the eyes. Further functions are discussed in the literature.Anatomically and physiologically it is proven that tactile hairs are part of a sensory organ and clearly differ from the body fur. Without them, the sensory organ is not functional. Trimming the vibrissae is therefore not at all a cosmetic measure in the context of grooming but constitutes a temporary amputation. By disabling a sensory organ, the animal suffers from temporary physical damage representing considerable harm. Thus, cutting the tactile hairs of the domestic dog for esthetic reasons is prohibited according to German, Austrian, and Swiss Animal Welfare Act.

Effekte unterschiedlicher Bluntingverfahren hinsichtlich der Tierwohlindikatoren nicht schnabelkupierter Putenhähne

Abstract In view of the planned abandonment of routine beak-trimming in turkeys in Germany, two different blunting methods were evaluated at the “Education, Research and Demonstration Centre of Poultry and Small Animal Farming” in Kitzingen (Germany) and the effects on selected welfare indicators for non beak-trimmed turkeys were examined. Altogether 746 male B. U. T. 6 turkey chicks of the breeding company Moorgut Kartzfehn von Kameke GmbH & Co. KG, Bösel, Germany were housed. For the first five weeks the chicks were reared in twelve compartments with a stocking density of 11.8 kg/m 2. For the actual examination during the fattening period (6.–21. live week), a total of 600 male turkeys were randomized to a total of 24 experimental compartments after the fifth week of life (planned stocking density: 51,9 kg/m 2) and the respective blunting method was installed into the pan feeding system of the compartments. The following control and experimental groups were used: K1: beak-trimmed turkeys without blunting (n = 150 animals); K2: non beak-trimmed turkeys without blunting (n = 150 animals); V1: non beak-trimmed turkeys with screed grinding disc as blunting method (n = 150 animals) and V2: non beak-trimmed turkeys with metal grid disc (n = 150 animals). In 28-days rhythms the turkeys were scored, the beak was measured and the weight of the animals was recorded. In addition, data on indoor and outdoor climate such as light intensity, gaseous ammonia content, temperature and humidity was collected. In addition 12 randomly selected turkeys from each variant were slaughtered in Kitzingen after the 17 th and 21 st week of life, and their heads examined macroscopically and histologically at the Bavarian State Office for Health and Food Safety in Erlangen (Bavaria, Germany). There were significant differences (p ≤ 0.05) between the experimental groups in the beak rating, concerning the length of the beak, the beak supernatant and the slaughter weight. Strong differences were found between the beak-trimmed and the non beak-trimmed turkeys. Significant (p ≤ 0.05) differences were also noted between the two blunting methods, for example in the upper beak supernatant: with screed grinding disc 3.02 mm and with the metal grid disc 4.00 mm. With regard to the morphology of the beak, a significant higher abrasion was achieved with screed grinding discs without any injury to the tactile organ.

Impairment of tactile responses and Piezo2 channel mechanotransduction in mice following chronic vincristine treatment

Loss of the sense of touch or numbness in fingertips and toes is one of the earliest sensory dysfunctions in patients receiving chemotherapy with anti-cancer drugs such as vincristine. However, mechanisms underlying this chemotherapy-induced sensory dysfunction is poorly understood. Whisker hair follicles are tactile organs in non-primate mammals which are functionally equivalent to human fingertips. Here we used mouse whisker hair follicles as a model system to explore how vincristine treatment induces the loss of the sense of touch. We show that chronic treatment of mice with vincristine impaired in vivo whisker tactile behavioral responses. In vitro electrophysiological recordings made from whisker hair follicle afferent nerves showed that mechanically evoked whisker afferent impulses were significantly reduced following vincristine treatment. Furthermore, patch-clamp recordings from Merkel cells of whisker hair follicles revealed a significant reduction of mechanically activated currents via Piezo2 channels in Merkel cells. Collectively, our results suggest that Piezo2 channel dysfunction in Merkel cells contribute to the loss of the sense of touch following the chemotherapy treatment regimen with vincristine.

Piezo2 Underlies Slowly-Inactivating Mechano-Current in Sensory Neurons from Tactile Specialist Birds

Mechano-gated ion channels are essential for the detection of touch by peripheral sensory neurons, but many aspects of touch physiology and mechanotransducer function remain obscure. Tactile specialist birds of the family Anatidae possess unique mechanosensory abilities with which they efficiently select edible matter in muddy water without visual or olfactory cues. Mechanical stimuli are transmitted by trigeminal mechanoreceptors innervating the bill, a highly specialized tactile organ. We show mechanosensory specialization in tactile, but not visually foraging birds involves the formation of functional rapidly-adapting mechanoreceptors that produce robust mechano-current via the Piezo2 channel with novel properties. Cloning and electrophysiological characterization of duck Piezo2 in a heterologous expression system shows that duck Piezo2 is functionally similar to the mouse orthologue, but with prolonged inactivation kinetics. We show that Piezo2 inactivation can be increased by co-expression with Tmem150C, a transmembrane protein that co-exists with Piezo2 in somatosensory neurons, suggesting a potential mechanism. Our results uncover possible evolutionary adaptations contributing to potentiation of mechanoreception in an organ-specific manner, and reveal the Piezo2 channel as a neuronal mechanotransducer with prolonged inactivation kinetics.

Daidalotarsonemus and Excelsotarsonemus species (Acari: Tarsonemidae) found in shaded cacao plantations in Brazil, with a description of a new species

ABSTRACTMites of the family Tarsonemidae (Acari: Prostigmata) exhibit a great diversity of feeding habits including fungivorous, algivorous, plant feeders, and predatory of other mites, as parasitoids and parasites are kinds of symbionts of other insects. They also have a considerable diversity of morphological structures, including the shape and structure of the mouthparts and specialized tactile organs, particularly the setae on the body and legs. The Atlantic Forest remnant is considered to be a very diverse tropical biota. Samples were collected on Theobroma cacao and Artocarpus heterophyllus trees in cabruca agroforest systems located in Ilhéus, Bahia State, Brazil. A new species, Excelsotarsonemus cabrucae Sousa, Lofego & Ochoa, sp. n. is described and illustrated. Six Daidalotarsonemus and three Excelsotarsonemus species were identified in the same area. A key to the species of Daidalotarsonemus of Brazil and a key to the species of Excelsotarsonemus of the world are presented. The findings emphasize the importance of conducting mite surveys in rainforests to better understand the mite diversity which inhabits this biome.http://www.zoobank.org/urn:lsid:zoobank.org:act:15D43DCE-E281-456F-B218-6F0947B6EA04

CNT コンポジット材料を用いた触覚器官の作製

CNT コンポジット材料を用いた触覚器官の作製

Observation Abilities and Observation Types of Plants Based on Elementary School Students’ Cognitive Style

The purpose of this study was to analyze elementary school 6 graders' observation abilities and observation types of plants by cognitive style. The students were divided into two groups which are dependent cognitive style and independent cognitive style according to their responses to cognitive style analysis. And then they performed five plants observation task. The findings of this study were as follows. First, it made no significant difference between observation abilities whether students cognitive type is dependent or independent. Second, there was difference between dependent and independent cognitive type students on using observation type. In using sense organs, group of dependent cognitive type students mainly depended on visual and tactile organ, whereas independent cognitive type students used more sense organs. Third, observation type on measurement was similar both of two groups. But there was clear distinguishing observation type on operation. The group of independent cognitive style used more operated observation than the group of dependent cognitive style.

THE SENSE ORGANS IN THE SKIN OF THE HEAD OF SQUAMATA (REPTILIA)

ABSTRACT Tactile sense organs in the skin of the head of 42 species belonging to several squamate families are described. These sense organs always consist of a dermal and an epidermal component. Six different types of these sense organs are distinguished. The sloughing cycle of the epidermal component of the sense organs occurs principally in the same manner as it does in the epidermis. The phenomenon of “persisting cells,” which occurs in some families, is discussed. Number and distribution of the organs are not considered.

The structure of tactile organs of the Russian desman (Desmana moschata L. 1758) and their role in orientation

The structure of tactile organs of the Russian desman (Desmana moschata L. 1758) and their role in orientation

The Star-Nosed Mole Reveals Clues to the Molecular Basis of Mammalian Touch

Little is known about the molecular mechanisms underlying mammalian touch transduction. To identify novel candidate transducers, we examined the molecular and cellular basis of touch in one of the most sensitive tactile organs in the animal kingdom, the star of the star-nosed mole. Our findings demonstrate that the trigeminal ganglia innervating the star are enriched in tactile-sensitive neurons, resulting in a higher proportion of light touch fibers and lower proportion of nociceptors compared to the dorsal root ganglia innervating the rest of the body. We exploit this difference using transcriptome analysis of the star-nosed mole sensory ganglia to identify novel candidate mammalian touch and pain transducers. The most enriched candidates are also expressed in mouse somatosesensory ganglia, suggesting they may mediate transduction in diverse species and are not unique to moles. These findings highlight the utility of examining diverse and specialized species to address fundamental questions in mammalian biology.

Detecting vibration source for the orientation behavior of sand scorpions

Sand scorpions can locate their prey through their vibration sensitivity. They have their tactile sense organs on their legs to detect vibration reaching their body. They show an orientation behavior towards their prey when there is any vibration signal generated by prey movement. How they respond to the vibration source is an open question. It is believed that stimulus-locked neuron firings from the sensor organs on each leg are processed and the brain system of sand scorpions has sensory projections from the sense organs. It is known that eight command neurons in the brain interact each other with triad inhibitions [1,2]. Then a population coding of the neuron activity determines the direction of vibration source [3]. We tested direction selectivity in the sand with an experimental setup to detect the vibration source as shown in Figure ​Figure1.1. Eight legs of sand scorpions are positioned almost in a rim of circle. We placed eight microphones in a circle and each microphone sensor detects the vibration signal. The positions of microphone sensors are similar to the foot positions of sand scorpions, that is, the same angular positions (at 18, 54, 90, 140, -140, -90, -54, and -18 degrees). A metal ball is dropped to produce disturbance vibration. Then the time course of vibration signals is received by each microphone sensor. The time delay of vibration for each leg is a prominent source to detect the direction of vibration. We observe P-wave and Rayleigh wave of vibration signals, where the P-wave corresponds to a compressional sound wave and Rayleigh wave is a surface wave easily found in the sand. Both P-wave and Rayleigh wave can provide a cue to detect direction of vibration source. Yet the Rayleigh wave can be observed with large amplitude while the P-wave with small amplitude is sensitive to noise. Figure 1 Experimental setup in the sand In our experiments, sensory activations depending on Rayleigh wave are measured with microphone sensors and a population coding of command neuron activities with triad inhibitions are applied to the time course of vibration sensor readings. The approach can estimate the direction of vibration source. Unlike the direction, the distance to a vibration source is not clearly measured in our experiments. The distance estimation seems to be involved with the intensity of vibration signals or the time difference between the P-wave and the Rayleigh wave. The time difference roughly guides the distance in the experiments, but it does not provide accurate results. It suggests that sand scorpions might focus on estimating the direction of the vibration source caused by a prey rather than accurately calculate how far away from their body a prey is. The distance accuracy may be achieved within small distances. Sand scorpions can orient towards their prey with high accuracy when there is any prey movement. We assume a circular array of directionally sensitive neurons with inhibition mechanism to explain the orientation behavior, receiving sensory signals of vibration as pointed out by other researchers [1,2]. What type of inhibition mechanism is available, how they detect the distance of a vibration source, or whether they can sense or use both the sound wave and surface wave is an open question. We need further study on these subjects. More sophisticated measurements and experiments of vibration signals might explain those questions partly.