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Background: The effectiveness of the quadratus lumborum block (QLB) for postoperative pain management depends on the injection pathway used. There is limited research on the block area produced by intramuscular injection of local anesthesia in the quadratus lumborum muscle. This study aimed to determine the cutaneous sensory blockade area produced by an intramuscular quadratus lumborum block (QLBi) at the L2 level. Methods: Twenty patients aged 18–60 years with ASA grade I-II and a BMI of 18–30 kg/m2 who were scheduled for open inguinal hernia repair with mesh underwent ultrasound-guided QLBi injection of 20 ml of 0.5% ropivacaine. The cutaneous sensory blockade area was measured by applying a cold stimulus 1 h after the block and then measured every hour after surgery until the sensation returned to normal. The duration of a blockade is defined as the time it takes for all affected areas to fully regain normal sensation following a blockade. Pain scores (numeric rating scale, NRS) were recorded at 2, 4, 8, 12, and 24 h after surgery. Adverse reactions to QLBi were recorded 24 h after surgery. Results: All 20 patients had reduced or lost cold sensation areas. The greatest extent of cold sensation reduction occurred at T7 (10%), and the least amount of cold sensation reduction occurred at L3 (10%). The block level covered T8 (20%), T9 (30%), T10 (45%), T11 (90%), T12 (95%), L1 (100%), and L2 (15%). Eighteen patients experienced areas of sensory loss, with the highest range at T11 and the lowest at L2. The duration of the blockade was 8.9 ± 3.8 h, with a maximum of 24 h and a minimum of 5 h. One patient experienced quadriceps weakness after surgery. Conclusion: Quadratus lumborum block of intramuscular pathway can produce effective cutaneous sensory blockade, which can be used for postoperative analgesia of indirect inguinal hernia operation, and may also be beneficial to analgesia of other lower abdominal operations. However, the best method needs further confirmation to determine specific anesthesia methods for various operations. Chinese clinical trial registry: June 2, 2018; ChiCTR1800016457. [ABSTRACT FROM AUTHOR]

Sneezing and coughing are primary symptoms of many respiratory viral infections and allergies. It is generally assumed that sneezing and coughing involve common sensory receptors and molecular neurotransmission mechanisms. Here, we show that the nasal mucosa is innervated by several discrete populations of sensory neurons, but only one population (MrgprC11+MrgprA3−) mediates sneezing responses to a multitude of nasal irritants, allergens, and viruses. Although this population also innervates the trachea, it does not mediate coughing, as revealed by our newly established cough model. Instead, a distinct sensory population (somatostatin [SST+]) mediates coughing but not sneezing, unraveling an unforeseen sensory difference between sneezing and coughing. At the circuit level, sneeze and cough signals are transmitted and modulated by divergent neuropathways. Together, our study reveals the difference in sensory receptors and neurotransmission/modulation mechanisms between sneezing and coughing, offering neuronal drug targets for symptom management in respiratory viral infections and allergies. [Display omitted] • Sneezing and coughing are mediated by distinct sensory populations • Nasal MrgprC11-expressing sensory neurons serve as a core "sneeze" population • Airway SST-expressing sensory neurons mediate chemically induced cough • Sneezing and coughing are transmitted and modulated by divergent neuropathways Sneezing and coughing are frequently associated with allergies and respiratory viral infections. This study reveals that sneezing and coughing are initiated by discrete sensory receptors and transmitted by divergent neuropathways, offering drug targets for managing pathological sneezing and coughing. [ABSTRACT FROM AUTHOR]

Animals have the innate ability to select optimal defensive behaviors with appropriate intensity within specific contexts. The vomeronasal organ (VNO) serves as a primary sensory channel for detecting predator cues by relaying signals to the medial hypothalamic nuclei, particularly the ventromedial hypothalamus (VMH), which directly controls defensive behavioral outputs. Here, we demonstrate that cat saliva contains predator cues that signal the imminence of predator threat and modulate the intensity of freezing behavior through the VNO in mice. Cat saliva activates VNO neurons expressing the V2R-A4 subfamily of sensory receptors, and the number of VNO neurons activated in response to saliva correlates with both the freshness of saliva and the intensity of freezing behavior. Moreover, the number of VMH neurons activated by fresh, but not old, saliva positively correlates with the intensity of freezing behavior. Detailed analyses of the spatial distribution of activated neurons, as well as their overlap within the same individual mice, revealed that fresh and old saliva predominantly activate distinct neuronal populations within the VMH. Collectively, this study suggests that there is an accessory olfactory circuit in mice that is specifically tuned to time-sensitive components of cat saliva, which optimizes their defensive behavior to maximize their chance of survival according to the imminence of threat. [ABSTRACT FROM AUTHOR]

This article from Frontiers in Education introduces students to somatosensation, focusing on elements such as pressure, vibration, light touch, temperature, pain, and proprioception. The lesson includes identifying somatosensory receptors, understanding how information is relayed to the brain, and performing activities to reinforce these concepts. The lesson is designed for 6th to 8th-grade students and aligns with the Next Generation Science Standard MS-LS1-8. The lesson aims to help students understand how sensory receptors respond to stimuli and how the brain processes this information for immediate behavior or memory storage. [Extracted from the article]

The article "Memory and Amnesia" in Frontiers in Education discusses a lesson plan for 7th and 8th-grade students to learn about different types of memory and amnesia. The lesson includes activities such as a working memory game, matching memories to their classifications, and analyzing memory loss in mock medical cases. The lesson aims to help students understand the various forms of memory and the causes of memory problems like amnesia. [Extracted from the article]

Diabetic peripheral neuropathy (DPN), a complication of diabetes mellitus (DM), is a neurodegenerative disorder that results from hyperglycemic damage and deficient insulin receptor (IR) signaling in peripheral nerves, triggered by failure of insulin production and insulin resistance. IR signaling plays an important role in nutrient metabolism and synaptic formation and maintenance in peripheral neurons. Although several animal models of DPN have been developed to identify new drug candidates using cytotoxic reagents, nutrientrich diets, and genetic manipulations, a model showing beneficial effects remains to be established. In this study, we aimed to develop a DPN animal model using zebrafish to validate the effects of drug candidates on sensory neuropathy through in vivo imaging during the early larval stage. To achieve this, we generated Tg (ins:gal4p16);Tg (5uas:epNTR-p2a-mcherry) zebrafish using an enhanced potency nitroreductase (epNTR)-mediated chemogenetic ablation system, which showed highly efficient ablation of pancreatic b-cells following treatment with low-dose metronidazole (MTZ). Using in vivo live imaging, we observed that sensory nerve endings and postsynaptic formation in the peripheral lateral line (PLL) were defective, followed by a disturbance in rheotaxis behavior without any locomotory behavioral changes. Despite defects in sensory nerves and elevated glucose levels, both reactive oxygen species (ROS) levels, a primary cause of DPN, and the number of ganglion cells, remained normal. Furthermore, we found that the activity of mTOR, a downstream target of IR signaling, was decreased in the PLL ganglion cells of the transgenic zebrafish. Our data indicates that peripheral neuropathy results from the loss of IR signaling due to insulin deficiency rather than hyperglycemia alone. [ABSTRACT FROM AUTHOR]

Memristors have emerged as a promising candidate to mimic the human behavior and thus unlocking the potential for bio‐inspired computing advancement. However, these devices operate at a voltages which are still far from the energy‐efficient biological counterpart, which uses an action potential of 50–120 mV to process the information. Here, a diffusive memristor is reported from synthetic WSe2 fabricated in Ag/WSe2/Au vertical device geometry. The devices operate at bio‐voltages of 40–80 mV with Ion/Ioff ratio of 106 and steep switching turn ON and OFF slopes of 0.77 and 0.88 mV per decade, respectively. The power consumption in standby mode and power per set transition are found to be 10 fW and 64 pW, respectively. Further, the diffusive memristors are utilized to emulate the nociceptor, a special receptor for sensory neurons that selectively responds to noxious stimuli. Nociceptor in turn imparts a warning signal to the central nervous system which then triggers the motor response to take precautionary actions to prevent the body from injury. The key features of a nociceptor including “threshold”, “relaxation”, “no‐adaptation” and “sensitization” are demonstrated using artificial nociceptors. These illustrations imply the feasibility of developing low‐power diffusive memristors for bio‐inspired computing, humanoid robots, and electronic skins. [ABSTRACT FROM AUTHOR]

Background • At present, some Guillain-Barre syndrome (GBS) patients have a relatively poor prognosis due to the lack of timely diagnosis, and the risk of death is difficult to reduce. At present, the level of clinical diagnosis of GBS is not ideal, and the time of clinical examination and diagnosis is relatively long. How to improve the level of clinical diagnosis, clinical treatment and prognosis of GBS has always been the focus of clinical research of GBS. This study mainly analyzes the application efficacy of limb peripheral nerve ultrasound in the diagnosis, classification and disease assessment of GBS, hoping to supplement the application research of limb peripheral nerve ultrasound in the diagnosis of GBS and provide some reference for the development of clinical diagnosis of GBS. Objective • To explore the application and value of limb peripheral nerve ultrasound in Guillain-Barre syndrome (GBS). Methods • In this case-control study, 35 GBS patients (GBS group) and 20 healthy volunteers (normal group) were enrolled, the ultrasound features of GBS, NCSA dimensions of limbs, NCSA sizes of limbs in patients with different types of GBS, and NCSA sizes of vagus nerves in patients with different conditions of GBS were clinically detected and collected.Pearson correlation coefficient was used to evaluate the correlation between limb nerve cross-sectional areas (NCSAs) and nerve electrophysiology indexes in GBS patients. The receiver operating characteristic curve (ROC) was adopted to analyze the value of limb NCSAs for diagnosing GBS. Results • Compared with the normal group, NCSAs of multiple limbs neurodes in the GBS group increased significantly (P < .05). Patients with different GBS classifications had significantly different limb NCSAs in the proximal or distal nerve (P < .05). Compared with patients without autonomic nervous dysfunction, patients combined with autonomic nervous dysfunction had significantly expanded NCSA of the vagus nerve (P < .05). NCSAs of the median nerve and ulnar nerve were negatively correlated with motor nerve conduction velocity (MCV) and positively correlated with compound muscle action potential (CMAP) latency (both P < .05); NCSA of the median nerve showed a negative correlation with sensory nerve conduction velocity (SCV) (P < .05).The ROC curve showed that the auc of ncsa of median nerve (median), ulnar nerve (proximal), vagus nerve, brachial plexus, and common peroneal nerve in the diagnosis of GBS were 0.851, 0.813, 0.783, 0.774, and 0.670, respectively (P < .05), which had diagnostic efficacy. The sensitivity were 85.36%, 80.08%, 78.85%, 76.93% and 70.88%, respectively. The specificity were 68.29%, 73.65%, 78.86%, 80.29% and 83.56%, respectively. Conclusion • Limbs peripheral nerve ultrasound can effectively assist the early diagnosis, classification, and assessment of the severity of illness of GBS, it has a good diagnostic effect on multi-limb ganglion NCSA and vagus nerve NCSA.In the future, the application of limb peripheral nerve ultrasound in the early diagnosis, classification and severity assessment of GBS can improve the efficacy of clinical diagnosis of GBS and provide a good basis for the improvement of prognosis of GBS. [ABSTRACT FROM AUTHOR]

Proprioception is the "sixth sense" that detects limb postures with motor neurons. It requires a natural integration between the musculoskeletal systems and sensory receptors, which is challenging among modern robots that aim for lightweight, adaptive, and sensitive designs at low costs in mechanical design and algorithmic computation. Here, we present the Soft Polyhedral Network with an embedded vision for physical interactions, capable of adaptive kinesthesia and viscoelastic proprioception by learning kinetic features. This design enables passive adaptations to omni-directional interactions, visually captured by a miniature high-speed motion-tracking system embedded inside for proprioceptive learning. The results show that the soft network can infer real-time 6D forces and torques with accuracies of 0.25/0.24/0.35 N and 0.025/0.034/0.006 Nm in dynamic interactions. We also incorporate viscoelasticity in proprioception during static adaptation by adding a creep and relaxation modifier to refine the predicted results. The proposed soft network combines simplicity in design, omni-adaptation, and proprioceptive sensing with high accuracy, making it a versatile solution for robotics at a low material cost with more than one million use cycles for tasks such as sensitive and competitive grasping and touch-based geometry reconstruction. This study offers new insights into vision-based proprioception for soft robots in adaptive grasping, soft manipulation, and human-robot interaction. [ABSTRACT FROM AUTHOR]

The Spanish neurohistologist Santiago Ramón y Cajal (1852-1934) is widely regarded as the father of modern Neuroscience. In addition to identifying the individuality of cells in the nervous system (the neuron theory) or the direction followed by nerve impulses (the principle of dynamic polarization), he described numerous details regarding the organization of the different structures of the nervous system. This task was compiled in his magnum opus, "Textura del Sistema Nervioso del Hombre y los Vertebrados," first published in Spanish between 1899 and 1904, and later revised and updated in French as "Histologie du système nerveux de l'homme et des vertébrés" between 1909 and 1911 for wider distribution among the international scientific community. Some of Cajal's findings are fundamental to our understanding of the anatomy and histology of the vestibular system. He depicted the nerve endings in the sensory epithelia, the structure of the vestibular nerve and Scarpa ganglion, afferent vestibular fibers, vestibular nuclei, lateral vestibulospinal tract, vestibulocerebellar connections, and the fine structure of the cerebellum. However, most of these pioneering descriptions were published years earlier in Spanish journals with limited circulation. Our study aimed to gather Cajal's findings on the vestibular system and identify his original publications. After this endeavor, we claim a place for Cajal among the founders of anatomy and histology of the vestibular system. [ABSTRACT FROM AUTHOR]

Nociceptors are key sensory receptors that transmit warning signals to the central nervous system in response to painful stimuli. This fundamental process is emulated in an electronic device by developing a novel artificial nociceptor with an ultrathin, nonstoichiometric gallium oxide (GaOx)‐silicon oxide heterostructure. A large‐area 2D‐GaOx film is printed on a substrate through liquid metal printing to facilitate the production of conductive filaments. This nociceptive structure exhibits a unique short‐term temporal response following stimulation, enabling a facile demonstration of threshold‐switching physics. The developed heterointerface 2D‐GaOx film enables the fabrication of fast‐switching, low‐energy, and compliance‐free 2D‐GaOx nociceptors, as confirmed through experiments. The accumulation and extrusion of Ag in the oxide matrix are significant for inducing plastic changes in artificial biological sensors. High‐resolution transmission electron microscopy and electron energy loss spectroscopy demonstrate that Ag clusters in the material dispersed under electrical bias and regrouped spontaneously when the bias is removed owing to interfacial energy minimization. Moreover, 2D nociceptors are stable; thus, heterointerface engineering can enable effective control of charge transfer in 2D heterostructural devices. Furthermore, the diffusive 2D‐GaOx device and its Ag dynamics enable the direct emulation of biological nociceptors, marking an advancement in the hardware implementation of artificial human sensory systems. [ABSTRACT FROM AUTHOR]

Aedes aegypti mosquitoes are major vectors of dengue, chikungunya, and other arboviral diseases. Ae. aegypti's capacity to reproduce and to spread disease depends on the female mosquitoes' ability to obtain blood meals and find water-filled containers in which to lay eggs (oviposit). While humidity sensation (hygrosensation) has been implicated in these behaviors, the specific hygrosensory pathways involved have been unclear. Here, we establish the distinct molecular requirements and anatomical locations of Ae. aegypti Dry Cells and Moist Cells and examine their contributions to behavior. We show that Dry Cell and Moist Cell responses to humidity involve different ionotropic receptor (IR) family sensory receptors, with dry air-activated Dry Cells reliant upon the IR Ir40α, and humid air-activated Moist Cells upon Ir68a. Both classes of hygrosensors innervate multiple antennal sensilla, including sensilla ampullacea near the antennal base as well as two classes of coeloconic sensilla near the tip. Dry Cells and Moist Cells each support behaviors linked to mosquito reproduction but contribute differently: Ir40α-dependent Dry Cells act in parallel with Ir68α-dependent Moist Cells to promote blood feeding, while oviposition site seeking is driven specifically by Ir68α-dependent Moist Cells. Together these findings reveal the importance of distinct hygrosensory pathways in blood feeding and oviposition site seeking and suggest Ir40α-dependent Dry Cells and Ir68α-dependent Moist Cells as potential targets for vector control strategies. [ABSTRACT FROM AUTHOR]

Recently developed optogenetic technology, which allows high‐fidelity control of neuronal activity, has been applied to investigate the neural circuits underlying sensory processing and behavior. The nasal cavity is innervated by the olfactory nerve and trigeminal nerve, which are closely related to common symptoms of rhinitis, such as impairment of smell, itching, and sneezing. The olfactory system has an amazing ability to distinguish thousands of odorant molecules at trace levels. However, there are many issues in olfactory sensing mechanisms that need to be addressed. Optogenetics offers a novel technical approach to solve this dilemma. Therefore, we review the recent advances in olfactory optogenetics to clarify the mechanisms of chemical sensing, which may help identify the mechanism of dysfunction and suggest possible treatments for impaired smell. Additionally, in rhinitis patients, alterations in the other nerve (trigeminal nerve) that innervates the nasal cavity can lead to hyperresponsiveness to various nociceptive stimuli and central sensitization, causing frequent and persistent itching and sneezing. In the last several years, the application of optogenetics in regulating nociceptive receptors, which are distributed in sensory nerve endings, and amino acid receptors, which are distributed in vital brain regions, to alleviate overreaction to nociceptive stimuli, has gained significant attention. Therefore, we focus on the progress in optogenetics and its application in neuromodulation of nociceptive stimuli and discuss the potential clinical translation for treating rhinitis in the future. [ABSTRACT FROM AUTHOR]

The marine microturbellarian Macrostomum lignano (Platyhelminthes, Rhabditophora) is an emerging laboratory model used by a growing community of researchers because it is easy to cultivate, has a fully sequenced genome, and offers multiple molecular tools for its study. M. lignano has a compartmentalized brain that receives sensory information from receptors integrated in the epidermis. Receptors of the head, as well as accompanying glands and specialized epidermal cells, form a compound sensory structure called the frontal glandular complex. In this study, we used semi-serial transmission electron microscopy (TEM) to document the types, ultrastructure, and three-dimensional architecture of the cells of the frontal glandular complex. We distinguish a ventral compartment formed by clusters of type 1 (multiciliated) sensory receptors from a central domain where type 2 (collar) sensory receptors predominate. Six different types of glands (rhammite glands, mucoid glands, glands with aster-like and perimaculate granula, vacuolated glands, and buckle glands) are closely associated with type 1 sensory receptors. Endings of a seventh type of gland (rhabdite gland) define a dorsal domain of the frontal glandular complex. A pair of ciliary photoreceptors is closely associated with the base of the frontal glandular complex. Bundles of dendrites, connecting the receptor endings with their cell bodies which are located in the brain, form the (frontal) peripheral nerves. Nerve fibers show a varicose structure, with thick segments alternating with thin segments, and are devoid of a glial layer. This distinguishes platyhelminths from larger and/or more complex invertebrates whose nerves are embedded in prominent glial sheaths. [ABSTRACT FROM AUTHOR]

This article discusses the role of sensory neurons in tissue repair and regeneration, particularly in the context of diabetic and neuropathic conditions. The authors found that nociceptive sensory neurons release calcitonin gene-related peptide (CGRP) in response to acute injury, which modulates immune cells and creates an anti-inflammatory and pro-healing environment. However, in diabetic patients, there is a decrease in CGRP levels, which may contribute to impaired tissue healing. The authors propose that delivering engineered CGRP or CGRP analogues could be a potential therapeutic strategy to promote tissue healing in diabetic patients and other conditions where immune responses are dysfunctional. However, caution is needed when using CGRP inhibitors, as they may impair wound healing. Overall, this discovery has the potential to improve healing outcomes and enhance quality of life for patients with various conditions. [Extracted from the article]

Background: Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae) is the main causative agent of flystrike of sheep in Australia and New Zealand. Female flies lay eggs in an open wound or natural orifice, and the developing larvae eat the host's tissues, a condition called myiasis. To improve our understanding of host-seeking behavior, we quantified gene expression in male and female antennae based on their behavior. Methods: A spatial olfactometer was used to evaluate the olfactory response of L. cuprina mated males and gravid females to fresh or rotting beef. Antennal RNA-Seq analysis was used to identify sensory receptors differentially expressed between groups. Results: Lucilia cuprina females were more attracted to rotten compared to fresh beef (> fivefold increase). However, males and some females did not respond to either type of beef. RNA-Seq analysis was performed on antennae dissected from attracted females, non-attracted females and males. Transcripts encoding sensory receptors from 11 gene families were identified above a threshold (≥ 5 transcript per million) including 49 ATP-binding cassette transporters (ABCs), two ammonium transporters (AMTs), 37 odorant receptors (ORs), 16 ionotropic receptors (IRs), 5 gustatory receptors (GRs), 22 odorant-binding proteins (OBPs), 9 CD36-sensory neuron membrane proteins (CD36/SNMPs), 4 chemosensory proteins (CSPs), 4 myeloid lipid-recognition (ML) and Niemann-Pick C2 disease proteins (ML/NPC2), 2 pickpocket receptors (PPKs) and 3 transient receptor potential channels (TRPs). Differential expression analyses identified sex-biased sensory receptors. Conclusions: We identified sensory receptors that were differentially expressed between the antennae of both sexes and hence may be associated with host detection by female flies. The most promising for future investigations were as follows: an odorant receptor (LcupOR46) which is female-biased in L. cuprina and Cochliomyia hominivorax Coquerel, 1858; an ABC transporter (ABC G23.1) that was the sole sensory receptor upregulated in the antennae of females attracted to rotting beef compared to non-attracted females; a female-biased ammonia transporter (AMT_Rh50), which was previously associated with ammonium detection in Drosophila melanogaster Meigen, 1830. This is the first report suggesting a possible role for ABC transporters in L. cuprina olfaction and potentially in other insects. [ABSTRACT FROM AUTHOR]

This historical review on the semantic evolution of human senses and sensors revealed that Aristotle’s list of the five senses sight, hearing, touch, taste, and smell is still in use among non-scientific lay persons. It is no surprise that his classification in the work “De Anima” (On the Soul) from 350  BC confuses the sensor “touch” with the now more comprehensively defined somatosensory system and that senses are missing such as the later discovered vestibular system and the musculotendinous proprioception of the position of parts of the body in space. However, it is surprising that in the three most influential ancient cultures, Egypt, Greece, and China—which shaped the history of civilization—the concept prevailed that the heart rather than the brain processes perception, cognition, and emotions. This “cardiocentric view” can be traced back to the “Doctrine of Aristotle,” the “Book of the Dead” in ancient Egypt, and the traditional Chinese medicine of correspondence documented in the book “Huang di Neijing.” In Greek antiquity the philosophers Empedocles, Democritus and Aristotle were proponents of the allocation of the spirit and the soul to the heart connected to the body via the blood vessels. Opponents were the pre-Socratic mathematician Pythagoras, the philosopher Plato, and especially the Greek physician Hippocrates who regarded the brain as the most powerful organ in humans in his work “De Morbo Sacro.” The Greek physician Galen of Pergamon further elaborated on the concept of the brain (“cephalocentric hypothesis”) connected to the body by a network of nerves. The fundamental concepts for understanding functions and disorders of the vestibular system, the perception of self-motion, verticality and balance control were laid by a remarkable group of 19th century scientists including Purkynӗ, Mach, Breuer, Helmholtz, and Crum-Brown. It was also in the 19th century that Bell described a new sense of a reciprocal sensorimotor loop between the brain and the muscles which he called “muscular sense,” later termed “kinaesthesia” by Bastian and defined in 1906 as “proprioception” by Sherrington as “the perception of joint and body movements as well as position of the body or body segments, in space.” Both, the vestibular system and proprioception could be acknowledged as senses six or seven. However, we hesitate to recommend “pain”—which is variously assigned to the somatosensory system or extero-, intero-, visceroception—as a separate sensory system. Pain sensors are often not specific but have multisensory functions. Because of this inconsistent, partly contradictory classification even by experts in the current literature on senses and sensors we consider it justified to recommend a comprehensive reorganization of classification features according to the present state of knowledge with an expansion of the number of senses. Such a project has also to include the frequent task-dependent multisensory interactions for perceptual and sensorimotor achievements, and higher functions or disorders of the visual and vestibular systems as soon as cognition or emotions come into play. This requires a cooperation of sensory physiologists, neuroscientists and experienced physicians involved in the management of patients with sensory and multisensory disorders. [ABSTRACT FROM AUTHOR]

Sulfur dioxide (SO2), a common environmental and industrial air pollutant, possesses a potent effect in eliciting cough reflex, but the primary type of airway sensory receptors involved in its tussive action has not been clearly identified. This study was carried out to determine the relative roles of three major types of vagal bronchopulmonary afferents [slowly adapting receptors (SARs), rapidly adapting receptors (RARs), and C-fibers] in regulating the cough response to inhaled SO2. Our results showed that inhalation of SO2 (300 or 600 ppm for 8 min) evoked an abrupt and intense stimulatory effect on bronchopulmonary C-fibers, which continued for the entire duration of inhalation challenge and returned toward the baseline in 1–2 min after resuming room air-breathing in anesthetized and mechanically ventilated mice. In stark contrast, the same SO2 inhalation challenge generated a distinct and consistent inhibitory effect on both SARs and phasic RARs; their phasic discharges synchronized with respiratory cycles during the baseline (breathing room air) began to decline progressively within 1–3 min after the onset of SO2 inhalation, ceased completely before termination of the 8-min inhalation challenge, and then slowly returned toward the baseline after >40 min. In a parallel study in awake mice, inhalation of SO2 at the same concentration and duration as that in the nerve recording experiments evoked cough responses in a pattern and time course similar to that observed in the C-fiber responses. Based on these results, we concluded that stimulation of vagal bronchopulmonary C-fibers is primarily responsible for triggering the cough response to inhaled SO2. NEW & NOTEWORTHY: This study demonstrated that inhalation of a high concentration of sulfur dioxide, an irritant gas and common air pollutant, completely and reversibly inhibited the neural activities of both slowly adapting receptor and rapidly adapting receptor, two major types of mechanoreceptors in the lungs with their activities conducted by myelinated fibers. Furthermore, the results of this study suggested that stimulation of vagal bronchopulmonary C-fibers is primarily responsible for triggering the cough reflex responses to inhaled sulfur dioxide. [ABSTRACT FROM AUTHOR]

The mammalian vomeronasal system enables the perception of chemical signals crucial for social communication via the receptor families V1R and V2R. These receptors are linked with the G-protein subunits, Gαi2 and Gαo, respectively. Exploring the evolutionary pathways of V1Rs and V2Rs across mammalian species remains a significant challenge, particularly when comparing genomic data with emerging immunohistochemical evidence. Recent studies have revealed the expression of Gαo in the vomeronasal neuroepithelium of wild canids, including wolves and foxes, contradicting predictions based on current genomic annotations. Our study provides detailed immunohistochemical evidence, mapping the expression of V2R receptors in the vomeronasal sensory epithelium, focusing particularly on wild canids, specifically wolves and foxes. An additional objective involves contrasting these findings with those from domestic species like dogs to highlight the evolutionary impacts of domestication on sensory systems. The employment of a specific antibody raised against the mouse V2R2, a member of the C-family of vomeronasal receptors, V2Rs, has confirmed the presence of V2R2-immunoreactivity (V2R2-ir) in the fox and wolf, but it has revealed the lack of expression in the dog. This may reflect the impact of domestication on the regression of the VNS in this species, in contrast to their wild counterparts, and it underscores the effects of artificial selection on sensory functions. Thus, these findings suggest a more refined chemical detection capability in wild species. [ABSTRACT FROM AUTHOR]

Neurological electronic skin (E-skin) can process and transmit information in a distributed manner that achieves effective stimuli perception, holding great promise in neuroprosthetics and soft robotics. Neurological E-skin with multifunctional perception abilities can enable robots to precisely interact with the complex surrounding environment. However, current neurological E-skins that possess tactile, thermal, and visual perception abilities are usually prepared with rigid materials, bringing difficulties in realizing biologically synapse-like softness. Here, we report a soft multifunctional neurological E-skin (SMNE) comprised of a poly(3-hexylthiophene) (P3HT) nanofiber polymer semiconductor-based stretchable synaptic transistor and multiple soft artificial sensory receptors, which is capable of effectively perceiving force, thermal, and light stimuli. The stretchable synaptic transistor can convert electrical signals into transient channel currents analogous to the biological excitatory postsynaptic currents. And it also possesses both short-term and long-term synaptic plasticity that mimics the human memory system. By integrating a stretchable triboelectric nanogenerator, a soft thermoelectric device, and an elastic photodetector as artificial receptors, we further developed an SMNE that enables the robot to make precise actions in response to various surrounding stimuli. Compared with traditional neurological E-skin, our SMNE can maintain the softness and adaptability of biological synapses while perceiving multiple stimuli including force, temperature, and light. This SMNE could promote the advancement of E-skins for intelligent robot applications. [ABSTRACT FROM AUTHOR]

Transient receptor potential melastatin 8 (TRPM8) is a temperature- and menthol-sensitive ion channel that contributes to diverse physiological roles, including cold sensing and pain perception. Clinical trials targeting TRPM8 have faced repeated setbacks predominantly due to the knowledge gap in unraveling the molecular underpinnings governing polymodal activation. A better understanding of the molecular foundations between the TRPM8 activation modes may aid the development of mode-specific, thermal-neutral therapies. Ancestral sequence reconstruction was used to explore the origins of TRPM8 activation modes. By resurrecting key TRPM8 nodes along the human evolutionary trajectory, we gained valuable insights into the trafficking, stability, and function of these ancestral forms. Notably, this approach unveiled the differential emergence of cold and menthol sensitivity over evolutionary time, providing a fresh perspective on complex polymodal behavior. These studies provide a paradigm for understanding polymodal behavior in TRPM8 and other proteins with the potential to enhance our understanding of sensory receptor biology and pave the way for innovative therapeutic interventions. [ABSTRACT FROM AUTHOR]

Sex pheromones play crucial role in mating behavior of moths, involving intricate recognition mechanisms. While insect chemical biology has extensively studied type I pheromones, type II pheromones remain largely unexplored. This study focused on Helicoverpa armigera, a representative species of noctuid moth, aiming to reassess its sex pheromone composition. Our research unveiled two previously unidentified candidate type II sex pheromones—3Z,6Z,9Z-21:H and 3Z,6Z,9Z-23:H—in H. armigera. Furthermore, we identified HarmOR11 as an orphan pheromone receptor of 3Z,6Z,9Z-21:H. Through AlphaFold2 structural prediction, molecular docking, and molecular dynamics simulations, we elucidated the structural basis and key residues governing the sensory nuances of both type I and type II pheromone receptors, particularly HarmOR11 and HarmOR13. This study not only reveals the presence and recognition of candidate type II pheromones in a noctuid moth, but also establishes a comprehensive structural framework for PRs, contributing to the understanding of connections between evolutionary adaptations and the emergence of new pheromone types. [ABSTRACT FROM AUTHOR]

The primary cilium, an antenna-like sensory organelle that protrudes from the surface of most eukaryotic cell types, has become a signaling hub of growing interest given that defects in its structure and/or function are associated with human diseases and syndromes, known as ciliopathies. With the continuously expanding role of primary cilia in health and diseases, identifying new players in ciliogenesis will lead to a better understanding of the function of this organelle. It has been shown that the primary cilium shares similarities with the immune synapse, a highly organized structure at the interface between an antigen-presenting or target cell and a lymphocyte. Studies have demonstrated a role for known cilia regulators in immune synapse formation. However, whether immune synapse regulators modulate ciliogenesis remains elusive. Here, we find that programmed death ligand 1 (PD-L1), an immune checkpoint protein and regulator of immune synapse formation, plays a role in the regulation of ciliogenesis. We found that PD-L1 is enriched at the centrosome/basal body and Golgi apparatus of ciliated cells and depleting PD-L1 enhanced ciliogenesis and increased the accumulation of ciliary membrane trafficking proteins Rab8a, BBS5, and sensory receptor protein PC-2. Moreover, PD-L1 formed a complex with BBS5 and PC-2. In addition, we found that depletion of PD-L1 resulted in the ciliary accumulation of Gli3 and the downregulation of Gli1. Our results suggest that PD-L1 is a new player in ciliogenesis, contributing to PC-2-mediated sensory signaling and the Hh signaling cascade. [ABSTRACT FROM AUTHOR]

Soft grippers are garnering increasing attention for their adeptness in conforming to diverse objects, particularly delicate items, without warranting precise force control. This attribute proves especially beneficial in unstructured environments and dynamic tasks such as food handling. Human hands, owing to their elevated dexterity and precise motor control, exhibit the ability to delicately manipulate complex food items, such as small or fragile objects, by dynamically adjusting their grasping configurations. Furthermore, with their rich sensory receptors and hand-eye coordination that provide valuable information involving the texture and form factor, real-time adjustments to avoid damage or spill during food handling appear seamless. Despite numerous endeavors to replicate these capabilities through robotic solutions involving soft grippers, matching human performance remains a formidable engineering challenge. Robotic competitions serve as an invaluable platform for pushing the boundaries of manipulation capabilities, simultaneously offering insights into the adoption of these solutions across diverse domains, including food handling. Serving as a proxy for the future transition of robotic solutions from the laboratory to the market, these competitions simulate real-world challenges. Since 2021, our research group has actively participated in RoboSoft competitions, securing victories in the Manipulation track in 2022 and 2023. Our success was propelled by the utilization of a modified iteration of our Retractable Nails Soft Gripper (RNSG), tailored to meet the specific requirements of each task. The integration of sensors and collaborative manipulators further enhanced the gripper's performance, facilitating the seamless execution of complex grasping tasks associated with food handling. This article encapsulates the experiential insights gained during the application of our highly versatile soft gripper in these competition environments. [ABSTRACT FROM AUTHOR]

Since the days of Ramón y Cajal, the vast diversity of neuronal and particularly dendrite morphology has been used to catalog neurons into different classes. Dendrite morphology varies greatly and reflects the different functions performed by different types of neurons. Significant progress has been made in our understanding of how dendrites form and the molecular factors and forces that shape these often elaborately sculpted structures. Here, we review work in the nematode Caenorhabditis elegans that has shed light on the developmental mechanisms that mediate dendrite morphogenesis with a focus on studies investigating ciliated sensory neurons and the highly elaborated dendritic trees of somatosensory neurons. These studies, which combine time-lapse imaging, genetics, and biochemistry, reveal an intricate network of factors that function both intrinsically in dendrites and extrinsically from surrounding tissues. Therefore, dendrite morphogenesis is the result of multiple tissue interactions, which ultimately determine the shape of dendritic arbors. [ABSTRACT FROM AUTHOR]

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The article "Neurons & Control of Movement" from Frontiers in Education discusses a lesson plan for middle school students to learn about the brain's role in voluntary movement and the communication between neurons. The lesson aims to help students recognize how neurons use electrical signaling to communicate and understand how signals from the brain control movement. The lesson includes hands-on activities using human-to-human interfaces and claw interfaces to demonstrate these concepts. The article provides resources for instructors and outlines the timeline for the lesson, emphasizing the importance of safety and careful handling of equipment. [Extracted from the article]

Background: Pain, an evolutionarily conserved warning system, lets us recognize threats and motivates us to adapt to those threats. Headache pain from migraine affects approximately 15% of the global population. However, the identity of any putative threat that migraine or headache warns us to avoid is unknown because migraine pathogenesis is poorly understood. Here, we show that a stress-induced increase in pituitary adenylate cyclase-activating polypeptide-38 (PACAP38), known as an initiator of allosteric load inducing unbalanced homeostasis, causes headache-like behaviour in male mice via mas-related G protein-coupled receptor B2 (MrgprB2) in mast cells. Methods: The repetitive stress model and dural injection of PACAP38 were performed to induce headache behaviours. We assessed headache behaviours using the facial von Frey test and the grimace scale in wild-type and MrgprB2-deficient mice. We further examined the activities of trigeminal ganglion neurons using in vivo Pirt-GCaMP Ca2+ imaging of intact trigeminal ganglion (TG). Results: Repetitive stress and dural injection of PACAP38 induced MrgprB2-dependent headache behaviours. Blood levels of PACAP38 were increased after repetitive stress. PACAP38/MrgprB2-induced mast cell degranulation sensitizes the trigeminovascular system in dura mater. Moreover, using in vivo intact TG Pirt-GCaMP Ca2+ imaging, we show that stress or/and elevation of PACAP38 sensitized the TG neurons via MrgprB2. MrgprB2-deficient mice showed no sensitization of TG neurons or mast cell activation. We found that repetitive stress and dural injection of PACAP38 induced headache behaviour through TNF-a and TRPV1 pathways. Conclusions: Our findings highlight the PACAP38-MrgprB2 pathway as a new target for the treatment of stress-related migraine headache. Furthermore, our results pertaining to stress interoception via the MrgprB2/PACAP38 axis suggests that migraine headache warns us of stress-induced homeostatic imbalance. [ABSTRACT FROM AUTHOR]

The function of peripheral nociceptors, the neurons that relay pain signals to the brain, are frequently tuned by local and systemic modulator substances. In this context, neurohormonal effects are emerging as an important modulatory mechanism, but many aspects remain to be elucidated. Here we report that gonadotropin-releasing hormone (GnRH), a brain-specific neurohormone, can aggravate pain by acting on nociceptors in mice. GnRH and GnRHR, the receptor for GnRH, are expressed in a nociceptor subpopulation. Administration of GnRH and its analogue, localized for selectively affecting the peripheral neurons, deteriorated mechanical pain, which was reproducible in neuropathic conditions. Nociceptor function was promoted by GnRH treatment in vitro, which appears to involve specific sensory transient receptor potential ion channels. These data suggest that peripheral GnRH can positively modulate nociceptor activities in its receptor-specific manner, contributing to pain exacerbation. Our study indicates that GnRH plays an important role in neurohormonal pain modulation via a peripheral mechanism. [ABSTRACT FROM AUTHOR]

Most of our daily activities hinge on our ability to perceive our surroundings, with our eyes serving as pivotal sensory receptors. Our brain processes the visual data captured by our eyes, crafting a three-dimensional representation of our environment that empowers us to navigate and execute tasks. However, individuals dealing with visual impairments experience either partial or complete absence of this visual perception. In the past, conditions like myopia and astigmatism also lacked effective treatments, yet advancements in science and technology have enabled the creation of corrective aids like eyeglasses or even minor surgical interventions for vision enhancement. Over the years, researchers have conducted extensive investigations to devise devices catering to the needs of the visually impaired. This manuscript focuses on diverse sensors applicable in navigation systems tailored for this demographic. The review delves into recent advancements in navigation tools designed for the visually impaired, encompassing sensors such as visual, proximity, and LiDAR sensors, among others. Sensors generate copious amounts of data, which undergo processing to simulate the surrounding environment. We underscore the unique capabilities of each sensor, as well as optimal combinations of sensors that yield superior results. The challenges associated with sensor utilization are also addressed, accompanied by potential strategies for overcoming them. Our survey reveals a prevalent trend in utilizing RGB-depth sensing cameras and ultrasonic sensors in tandem with other sensor types for navigation purposes. This study aims to furnish a comprehensive overview of contemporary progress within the realm of navigation aids for the visually impaired, ultimately aiding researchers in discerning the most suitable technological approaches based on specific applications. [ABSTRACT FROM AUTHOR]

As they are nanoparticles with a zero dimension, they can be divided into three classes: organic, inorganic and composite. The different physico-chemical characteristics of nanoparticles make them useful in many areas including medicine, pharmaceuticals and the food industry. However, having standardized toxicological studies is very important due to their ability to prevent the occurrence of neurotoxic effects although at the same time improving diagnosis and treatment of brain diseases. The main aim of this article is to shed light upon pros and cons associated with using nanoparticles for brain health. Given the growing number of medical products that are incorporating silver nanoparticles, consumer safety has now become a priority. Nanoparticles can be produced using three techniques; these include chemical, physical or biological methods. The final method is theoretically safe; the first two however entail various health risks. We therefore sought to examine histological alterations in the cerebellum of neonates. Each nanoparticle type has unique characteristics which are associated with different routes. The nanoparticles cannot cross into the brain without these checks. One such route which is bypassed by its own barriers is through blood-brain barrier as direct sensory nerves to brain. These nanoparticles impair sensory neurons and receptors making central nervous system neurotoxic. [ABSTRACT FROM AUTHOR]

Obesity is considered the leading public health problem in the medical sector. The phenotype includes overweight conditions that lead to several other comorbidities that drastically decrease health. Glucagon-like receptor agonists (GLP-1RAs) initially designed for treating type 2 diabetes mellitus (T2DM) had demonstrated weight loss benefits in several clinical trials. In vivo studies showed that GLP-1RA encourages reduced food consumption and consequent weight reduction by stimulating brown fat and enhancing energy outlay through the action of the sympathetic nervous system (SNS) pathways. Additionally, GLP-1RAs were found to regulate food intake through stimulation of sensory neurons in the vagus, interaction with the hypothalamus and hindbrain, and through inflammation and intestinal microbiota. However, the main concern with the use of GLP-1RA treatment was weight gain after withdrawal or discontinuation. We could identify three different ways that could lead to weight gain. Potential factors might include temporary hormonal adjustment in response to weight reduction, the central nervous system's (CNS) incompetence in regulating weight augmentation owing to the lack of GLP-1RA, and β-cell malfunction due to sustained exposure to GLP-1RA. Here, we also review the data from clinical studies that reported withdrawal symptoms. Although the use of GLP-1RA could be beneficial in multiple ways, withdrawal after years has the symptoms reversed. Clinical studies should emphasize the downside of these views we highlighted, and mechanistic studies must be carried out for a better outcome with GLP-1RA from the laboratory to the bedside. [ABSTRACT FROM AUTHOR]

In the present work, we study the effect of different stimuli (living preys, its homogenate, and reduced glutathione (GSH)) on the discharge of desmonemes in the freshwater cnidarian, Hydra plagiodesmica (Dioni, 1968) (Cnidaria: Hydrozoa). Once confirmed their stimulatory effect, we choose GSH to analyze the relevance of Ca2+, the probable identity of the sensory receptor molecule, and the specific signalling pathway driving the discharge mechanism. Our results show that not only mechanical, but also chemical stimuli by itself may stimulate the discharge of desmonemes. Using calcium chelators, we verify that the discharge mechanism triggered by GSH is dependent on calcium. By mean of drugs that inhibit proteins pertaining to canonical signalling pathways, including GPCRs, we show that GSH causes the influx of Ca2+ via L-type voltage sensitive calcium channel (VGCC), and its release by mean of endoplasmic reticulum calcium channels. Moreover, our results suggest that the putative receptor for GSH is a GPCR coupled to Gq, which produces IP3 and Ca2+ as second messengers. Finally, we show that the genome of Hydra vulgaris (Pallas, 1766) predicts the existence of the different subunits of L-type VGCC, showing a high level of conservation when compared with other groups of Metazoa. [ABSTRACT FROM AUTHOR]

Olfaction is the major sense of smell in teleost involved in many physiological response and habitat acclimatization including food searching, migration for spawning, predator avoidance, reproduction behavior, as well as identification of fish of the same species. Our study illustrates the ultrastructure of the olfactory rosette of the grass carp Ctenopharyngodon idella (Cuvier and Valenciennes, 1844) by using Scanning Electron Microscope (SEM) and transmission Electron Microscope (TEM). Herein, the peripheral olfactory organs are represented by two olfactory rosettes lying in two nasal chambers, one on each side of fish snout. Each nasal chambers opens to the exterior by two nostrils a narrow inlet and wider outlet, segregated by a somewhat elevated, nasal bridge. The two nostrils are somewhat faraway as far as length of rosette's length to permit entering and leave water flow bearing odorant molecules to the nasal cavities. The SEM revealed that each olfactory rosette is elongated oval-shaped and made up of 48-50 foliar lamellae transversely arranged on both sides of a narrow median raphe. Alongside, the magnitude of lamellae differs in relation to their location on the raphe, since the larger are in the middle whereas their dimensions gradually reduced towards both ends of the rosette indicating that the number and magnitude of lamellae increase as the fish grow. Moreover, the lamellar surface comprises sensory and non-sensory areas concealed in a mucous layer and not distributed uniformly within the epithelial surface of the olfactory lamellae. Accordingly, The TEM observations indicated that the sensory areas holds four main receptor neurons, two are major including ciliated and microvillous receptor cells bearing either cilia or microvilli, respectively emitted from a dendritic knob. Additionally, two other minor rod-tipped and crypt cells bearing a compound rod cilium, or few microvilli and occult cilia emitted also from dendritic knob were rarely observed. From the other side, the non-sensory area comprises cylindrical flat top surface; ciliated non-sensory cells with motile long kinocilium and nonciliated stratified epithelial cells with fingerprint-like microridges both are mainly of supporting in addition of and ovoid goblet mucous cells in-between and stem basal cells. Collectively, our study revealed the general organization and ultrastructure of an important economic teleost fish that affects feeding habitat and has an important influence on the fish food intake. [ABSTRACT FROM AUTHOR]

Simple Summary: Leptophallus nigrovenosus is a trematode parasite found in snakes that requires feeding on amphibians to acquire the parasite. Firstly, this study investigated, in detail, the sensory receptors on the cercariae of these parasites, shedding light on the adaptations that allow them to find their host species. Secondly, the metacercariae of Salamandra salamandra were studied using histology to examine inflammatory responses in the eyes and potential eye damage. This study involved collecting snails (Planorbius metidjensis) and observing the emergence of cercariae. Salamander larvae were then exposed to these cercariae, and the larvae were later examined for the presence of metacercariae. Notably, this study is the first to report the presence of L. nigrovenosus in the snail P. metidjensis, a previously unrecorded host. These findings revealed that members of the genus Salamandra can serve as secondary intermediate hosts for L. nigrovenosus. Such infections in amphibians can lead to various eye issues, including cloudiness, inflammation, and tissue damage, ultimately affecting their survival. This research highlights the need for further investigation into trematode infections in amphibian eyes, which would provide valuable insights into their prevalence, transmission dynamics, and impact on host populations. (1) Background: Leptophallus nigrovenosus, an esophageal parasite that primarily affects water snakes of the genus Natrix, has a known life cycle that involves snail and amphibian hosts. However, the biological aspects, chaetotaxic patterns, and pathogeny of this parasite in its hosts have not been fully elucidated. (2) Methods: Snails (Planorbarius metidjensis) were collected in Spain and examined for cercaria emergence. The larvae were used to experimentally infect Salamandra salamandra, and metacercariae were isolated. Their chaetotaxy was studied using microscopy and scanning electron microscopy. The eye histology was also examined. (3) Results: The cercariae displayed distinctive morphological characteristics. The results of this study revealed three types of ciliated sensory papillae on the cercarial teguments, suggesting an adaptation for host detection and orientation. The metacercariae isolated from subcutaneous tissues showed oval bodies covered in spines. The chaetotaxy patterns matched those of Leptophallinae species. This is the first report of the presence of L. nigrovenosus in the snail P. metidjensis. Additionally, this study detected metacercariae in the eyes of S. salamandra, emphasizing the need for further research on trematode infections in amphibian eyes. (4) Conclusions: Members of the genus Salamandra can serve as secondary intermediate hosts for L. nigrovenosus, and the presence of metacercariae in amphibian eyes may have implications for the survival and habitat management of these amphibians. Understanding this parasite's prevalence, transmission dynamics, and impacts on host populations is crucial for conservation strategies. [ABSTRACT FROM AUTHOR]

Somatosensory innervation of the oral cavity enables the detection of a range of environmental stimuli including minute and noxious mechanical forces. The trigeminal sensory neurons underlie sensation originating from the tooth. Prior work has provided important physiological and molecular characterization of dental pulp sensory innervation. Clinical dental experiences have informed our conception of the consequence of activating these neurons. However, the biological role of sensory innervation within the tooth is yet to be defined. Recent transcriptomic data, combined with mouse genetic tools, have the capacity to provide important cell-type resolution for the physiological and behavioral function of pulp-innervating sensory neurons. Importantly, these tools can be applied to determine the neuronal origin of acute dental pain that coincides with tooth damage as well as pain stemming from tissue inflammation (i.e., pulpitis) toward developing treatment strategies aimed at relieving these distinct forms of pain. [ABSTRACT FROM AUTHOR]

The vomeronasal organ (VNO) is a tubular pheromone-sensing organ in which the lumen is covered with sensory and non-sensory epithelia. This study used immunohistochemistry and lectin histochemistry techniques to evaluate developmental changes, specifically of the glycoconjugate profile, in the horse VNO epithelium. Immunostaining analysis revealed PGP9.5 expression in some vomeronasal non-sensory epithelium (VNSE) cells and in the vomeronasal receptor cells of the vomeronasal sensory epithelium (VSE) in fetuses, young foals, and adult horses. Olfactory marker protein expression was exclusively localized in receptor cells of the VSE in fetuses, young foals, and adult horses and absent in VNSE. To identify the glycoconjugate type, lectin histochemistry was performed using 21 lectins. Semi-quantitative analysis revealed that the intensities of glycoconjugates labeled with WGA, DSL, LEL, and RCA120 were significantly higher in adult horse VSE than those in foal VSE, whereas the intensities of glycoconjugates labeled with LCA and PSA were significantly lower in adult horse VSE. The intensities of glycoconjugates labeled with s-WGA, WGA, BSL-II, DSL, LEL, STL, ConA, LCA, PSA, DBA, SBA, SJA, RCA120, jacalin, and ECL were significantly higher in adult horse VNSE than those in foal VNSE, whereas the intensity of glycoconjugates labeled with UEA-I was lower in adult horse VNSE. Histochemical analysis of each lectin revealed that various glycoconjugates in the VSE were present in the receptor, supporting, and basal cells of foals and adult horses. A similar pattern of lectin histochemistry was also observed in the VNSE of foals and adult horses. In conclusion, these results suggest that there is an increase in the level of N-acetylglucosamine (labeled by WGA, DSL, LEL) and galactose (labeled by RCA120) in horse VSE during postnatal development, implying that they may influence the function of VNO in adult horses. [ABSTRACT FROM AUTHOR]

Botulinum neurotoxins (BoNTs), derived from Clostridium botulinum, have been employed to treat a range of central and peripheral neurological disease. Some studies indicate that BoNT may be beneficial for pain conditions as well. It has been hypothesized that BoNTs may exert their analgesic effects by preventing the release of pain‐related neurotransmitters and neuroinflammatory agents from sensory nerve endings, suppressing glial activation, and inhibiting the transmission of pain‐related receptors to the neuronal cell membrane. In addition, there is evidence to suggest that the central analgesic effects of BoNTs are mediated through their retrograde axonal transport. The purpose of this review is to summarize the experimental evidence of the analgesic functions of BoNTs and discuss the cellular and molecular mechanisms by which they can act on pain conditions. Most of the studies reviewed in this article were conducted using BoNT/A. The PubMed database was searched from 1995 to December 2022 to identify relevant literature. [ABSTRACT FROM AUTHOR]

Introduction: Many marine organisms have a biphasic life cycle that transitions between a swimming larva with a more sedentary adult form. At the end of the first phase, larvae must identify suitable sites to settle and undergo a dramatic morphological change. Environmental factors, including photic and chemical cues, appear to influence settlement, but the sensory receptors involved are largely unknown. We targeted the protein receptor, opsin, which belongs to large superfamily of transmembrane receptors that detects environmental stimuli, hormones, and neurotransmitters. While opsins are well-known for light-sensing, including vision, a growing number of studies have demonstrated light-independent functions. We therefore examined opsin expression in the Pteriomorphia, a large, diverse clade of marine bivalves, that includes commercially important species, such as oysters, mussels, and scallops. Methods: Genomic annotations combined with phylogenetic analysis show great variation of opsin abundance among pteriomorphian bivalves, including surprisingly high genomic abundance in many species that are eyeless as adults, such as mussels. Therefore, we investigated the diversity of opsin expression from the perspective of larval development. We collected opsin gene expression in four families of Pteriomorphia, across three distinct larval stages, i.e., trochophore, veliger, and pediveliger, and compared those to adult tissues. Results: We found larvae express all opsin types in these bivalves, but opsin expression patterns are largely species-specific across development. Few opsins are expressed in the adult mantle, but many are highly expressed in adult eyes. Intriguingly, opsin genes such as retinochrome, xenopsins, and Go-opsins have higher levels of expression in the later larval stages when substrates for settlement are being tested, such as the pediveliger. Conclusion: Investigating opsin gene expression during larval development provides crucial insights into their intricate interactions with the surroundings, which may shed light on how opsin receptors of these organisms respond to various environmental cues that play a pivotal role in their settlement process. [ABSTRACT FROM AUTHOR]

• The mineralocorticoid receptor, expressed in DRG, may have a pro-inflammatory role. • Local MR blockade improves pain behaviors in a mouse radiculopathy model. • Sensory neuron specific MR knockout does not affect pain behaviors. • Unexpectedly, sensory neuron MR knockout increases nociceptor excitability. • These complexities may be relevant to understanding epidural steroid treatments. Corticosteroids are commonly used in the treatment of inflammatory low back pain, and their nominal target is the glucocorticoid receptor (GR) to relieve inflammation. They can also have similar potency at the mineralocorticoid receptor (MR). The MR has been shown to be widespread in rodent and human dorsal root ganglia (DRG) neurons and non-neuronal cells, and when MR antagonists are administered during a variety of inflammatory pain models in rats, pain measures are reduced. In this study we selectively knockout (KO) the MR in sensory neurons to determine the role of MR in sensory neurons of the mouse DRG in pain measures as MR antagonism during the local inflammation of the DRG (LID) pain model. We found that MR antagonism using eplerenone reduced evoked mechanical hypersensitivity during LID, but MR KO in paw-innervating sensory neurons only did not. This could be a result of differences between prolonged (MR KO) versus acute (drug) MR block or an indicator that non-neuronal cells in the DRG are driving the effect of MR antagonists. MR KO unmyelinated C neurons are more excitable under normal and inflamed conditions, while MR KO does not affect excitability of myelinated A cells. MR KO in sensory neurons causes a reduction in overall GR mRNA but is protective against reduction of the anti-inflammatory GRα isoform during LID. These effects of MR KO in sensory neurons expanded our understanding of MR's functional role in different neuronal subtypes (A and C neurons), and its interactions with the GR. [ABSTRACT FROM AUTHOR]

Acoel flatworms possess epidermal sensory-receptor cells on their body surfaces and exhibit behavioral repertoires such as geotaxis and phototaxis. Acoel epidermal sensory receptors should be mechanical and/or chemical receptors; however, the mechanisms of their sensory reception have not been elucidated. We examined the three-dimensional relationship between epidermal sensory receptors and their innervation in an acoel flatworm, Praesagittifera naikaiensis. The distribution of the sensory receptors was different between the ventral and dorsal sides of worms. The nervous system was mainly composed of a peripheral nerve net, an anterior brain, and three pairs of longitudinal nerve cords. The nerve net was located closer to the body surface than the brain and the nerve cords. The sensory receptors have neural connections with the nerve net in the entire body of worms. We identified five homologs of polycystic kidney disease (PKD): PKD1-1, PKD1-2, PKD1-3, PKD1-4, and, PKD2, from the P. naikaiensis genome. All of these PKD genes were implied to be expressed in the epidermal sensory receptors of P. naikaiensis. PKD1-1 and PKD2 were dispersed across the entire body of worms. PKD1-2, PKD1-3, and PKD1-4 were expressed in the anterior region of worms. PKD1-4 was also expressed around the mouth opening. Our results indicated that P. naikaiensis possessed several types of epidermal sensory receptors to convert various environmental stimuli into electrical signals via the PKD channels and transmit the signals to afferent nerve and/or effector cells. [ABSTRACT FROM AUTHOR]

This study aims to determine the molecular mechanisms and analgesic effects of transient receptor potential vanilloid 1 (TRPV1) in the treatments of osteoarthritis (OA) and rheumatoid arthritis (RA). We summarize and analyse current studies regarding the biological functions and mechanisms of TRPV1 in arthritis. We search and analyse the related literature in Google Scholar, Web of Science and PubMed databases from inception to September 2023 through the multi-combination of keywords like 'TRPV1', 'ion channel', 'osteoarthritis', 'rheumatoid arthritis' and 'pain'. TRPV1 plays a crucial role in regulating downstream gene expression and maintaining cellular function and homeostasis, especially in chondrocytes, synovial fibroblasts, macrophages and osteoclasts. In addition, TRPV1 is located in sensory nerve endings and plays an important role in nerve sensitization, defunctionalization or central sensitization. TRPV1 is a non-selective cation channel protein. Extensive evidence in recent years has established the significant involvement of TRPV1 in the development of arthritis pain and inflammation, positioning it as a promising therapeutic target for arthritis. TRPV1 likely represents a feasible therapeutic target for the treatment of OA and RA. [ABSTRACT FROM AUTHOR]

Background: Diabetic peripheral neuropathy (DPN) involves a very complex pathogenesis, and there is no neuro-specific marker for risk prediction. Neuron-specific enolase (NSE), a key enzyme in glycolysis, has a broad spectrum neurotrophic and neuroprotective effect on neurons, and also cause injury and inflammatory response of peripheral nerves. The relationship between neuron-specific enolase, highly sensitive c-reactive protein (hsCRP), and diabetic peripheral neuropathy remains unclear. We aimed to investigate whether elevated serum NSE and hsCRP levels increased the risk of DPN in patients with type 2 diabetes. Materials and methods: In this prospective nested case–control study, a total of 1072 eligible subjects with type 2 diabetes constituted the follow-up cohort. Demographic data and parameters including serum NSE and hsCRP were collected at baseline. Two neuropathy screening scales (MNSI and MDNS) were used to assess DPN during follow-up period. Nerve conduction studies were performed at the end of follow-up. Conditional logistic regression was used to inspect the risk factors of the incidence of DPN. Results: During an average follow-up period of 5.1 years, 176 subjects developed DPN. Serum NSE and hsCRP levels at baseline were significantly higher in DPN group than in matched non-DPN groups (p < 0.001). NSE was positively correlated with age and hsCRP (p < 0.001). The amplitude of sensory nerve action potential and compound muscle action potential of the lower extremity nerves were significantly decreased in the high tertile of NSE. After adjustment for matching and confusing factor, conditional logistic regression showed the risk of DPN in the high tertile of NSE level was still 3.176 times higher than that in the low tertile of NSE level (p < 0.001). Conclusion: Elevated serum NSE levels predicted the high incidence of DPN in Chinese patients with type 2 diabetes for an average of 5.1 years, which may be associated with increased neuroinflammatory response caused by high NSE levels, but further studies are needed. [ABSTRACT FROM AUTHOR]

This historical review on the semantic evolution of human senses and sensors revealed that Aristotle’s list of the five senses sight, hearing, touch, taste, and smell is still in use among non-scientific lay persons. It is no surprise that his classification in the work “De Anima” (On the Soul) from 350 BC confuses the sensor “touch” with the now more comprehensively defined somatosensory system and that senses are missing such as the later discovered vestibular system and the musculotendinous proprioception of the position of parts of the body in space. However, it is surprising that in the three most influential ancient cultures, Egypt, Greece, and China—which shaped the history of civilization—the concept prevailed that the heart rather than the brain processes perception, cognition, and emotions. This “cardiocentric view” can be traced back to the “Doctrine of Aristotle,” the “Book of the Dead” in ancient Egypt, and the traditional Chinese medicine of correspondence documented in the book “Huang di Neijing.” In Greek antiquity the philosophers Empedocles, Democritus and Aristotle were proponents of the allocation of the spirit and the soul to the heart connected to the body via the blood vessels. Opponents were the pre-Socratic mathematician Pythagoras, the philosopher Plato, and especially the Greek physician Hippocrates who regarded the brain as the most powerful organ in humans in his work “De Morbo Sacro.” The Greek physician Galen of Pergamon further elaborated on the concept of the brain (“cephalocentric hypothesis”) connected to the body by a network of nerves. The fundamental concepts for understanding functions and disorders of the vestibular system, the perception of self-motion, verticality and balance control were laid by a remarkable group of 19th century scientists including Purkynӗ, Mach, Breuer, Helmholtz, and Crum-Brown. It was also in the 19th century that Bell described a new sense of a reciprocal sensorimotor loop between the brain and the muscles which he called “muscular sense,” later termed “kinaesthesia” by Bastian and defined in 1906 as “proprioception” by Sherrington as “the perception of joint and body movements as well as position of the body or body segments, in space.” Both, the vestibular system and proprioception could be acknowledged as senses six or seven. However, we hesitate to recommend “pain”—which is variously assigned to the somatosensory system or extero-, intero-, visceroception—as a separate sensory system. Pain sensors are often not specific but have multisensory functions. Because of this inconsistent, partly contradictory classification even by experts in the current literature on senses and sensors we consider it justified to recommend a comprehensive reorganization of classification features according to the present state of knowledge with an expansion of the number of senses. Such a project has also to include the frequent task-dependent multisensory interactions for perceptual and sensorimotor achievements, and higher functions or disorders of the visual and vestibular systems as soon as cognition or emotions come into play. This requires a cooperation of sensory physiologists, neuroscientists and experienced physicians involved in the management of patients with sensory and multisensory disorders.

Previous work identified nociceptive Schwann cells that can initiate pain. Consistent with the existence of inherently mechanosensitive sensory Schwann cells, we found that in mice, the mechanosensory function of almost all nociceptors, including those signaling fast pain, were dependent on sensory Schwann cells. In polymodal nociceptors, sensory Schwann cells signal mechanical, but not cold or heat pain. Terminal Schwann cells also surround mechanoreceptor nerve-endings within the Meissner's corpuscle and in hair follicle lanceolate endings that both signal vibrotactile touch. Within Meissner´s corpuscles, two molecularly and functionally distinct sensory Schwann cells positive for Sox10 and Sox2 differentially modulate rapidly adapting mechanoreceptor function. Using optogenetics we show that Meissner's corpuscle Schwann cells are necessary for the perception of low threshold vibrotactile stimuli. These results show that sensory Schwann cells within diverse glio-neural mechanosensory end-organs are sensors for mechanical pain as well as necessary for touch perception. Schwann cells associated with most sensory receptors in the skin actively participate in the transduction of mechanical stimuli. Here the authors show that silencing these sensory Schwann cells is sufficient to reduce touch perception and can inhibit mechanical pain in mice. [ABSTRACT FROM AUTHOR]

Force feedback could be valuable in adapting walking to diverse terrains, but the effects of changes in substrate inclination on discharges of sensory receptors that encode forces have rarely been examined. In insects, force feedback is provided by campaniform sensilla, mechanoreceptors that monitor forces as cuticular strains. We neurographically recorded responses of stick insect tibial campaniform sensilla to "naturalistic" forces (joint torques) that occur at the hind leg femur-tibia (FT) joint in uphill, downhill, and level walking. The FT joint torques, obtained in a previous study that used inverse dynamics to analyze data from freely moving stick insects, are quite variable during level walking (including changes in sign) but are larger in magnitude and more consistent when traversing sloped surfaces. Similar to vertebrates, insects used predominantly extension torque in propulsion on uphill slopes and flexion torques to brake forward motion when going downhill. Sensory discharges to joint torques reflected the torque direction but, unexpectedly, often occurred as multiple bursts that encoded the rate of change of positive forces (dF/dt) even when force levels were high. All discharges also showed hysteresis (history dependence), as firing substantially decreased or ceased during transient force decrements. These findings have been tested in simulation in a mathematical model of the sensilla (Szczecinski NS, Dallmann CJ, Quinn RD, Zill SN. Bioinspir Biomim 16: 065001, 2021) that accurately reproduced the biological data. Our results suggest the hypothesis that sensory feedback from the femoro-tibial joint indicating force dynamics (dF/dt) can be used to counter the instability in traversing sloped surfaces in animals and, potentially, in walking machines. [ABSTRACT FROM AUTHOR]

The transduction from mechanical to electrical signal or energy, and vice versa, has wide applications spanning wearable electronics, medical devices, human‐machine interfaces, prosthetics, synthetic biology, soft robotics, augmented reality (AR), internet‐of‐things (IoT), smart cities, environmental monitoring, energy conversation, and energy harvesting. Although many biological processes such as those in sensory receptors and cell communication uses ions, much of existing artificial intelligent sensory and processing systems operate based solely on electrons as signal or energy carriers. Therefore, the realization of natively ionic devices can significantly advance the frontiers of both capabilities and applications. This invited paper introduces the piezoionic effect, surveying the historical evolution, scientific description, methodology, application, future outlook, and current debates. This work complements existing ones in that it is an in‐depth analysis of key attributes of the piezoionics field but, unlike a conventional review, does not emphasize the categorization of individual works, though is also provided. This work is also aimed at facilitating the understanding and evaluation of the piezoionics field in terms of its key capabilities, promises, fundamental limitations, technical challenges, and practical applications. Piezoionics as a biomimetic mechanical‐electrical transduction mechanism is expected to grow rapidly. Through in‐depth analysis and working out implications for the future, it is hoped that this paper provides a foundation for further exploration, discussion, and collaboration across different fields. The community looks forward to the piezoionic effect evolving into a mainstream paradigm for the ubiquitous realization of sensors, actuators, interfaces, as well as energy harvesters and beyond. [ABSTRACT FROM AUTHOR]

Calcitonin gene-related peptide (CGRP), a neuropeptide composed of 37 amino acids secreted from the sensory nerve endings, reportedly possesses various physiological effects, such as vasodilation and neurotransmission. Recently, there have been increasing reports of the involvement of CGRP in bone metabolism; however, its specific role in the pathogenesis of periodontitis, particularly in the repair and healing processes, remains to be elucidated. Therefore, this study aimed to investigate dynamic expression patterns of CGRP during the destruction and regeneration processes of periodontal tissues in a mouse model of experimental periodontitis. We also explored the effects of CGRP on periodontal ligament cells, which can differentiate to hard tissue-forming cells (cementoblasts or osteoblasts). Our findings demonstrated that CGRP stimulation promotes the differentiation of periodontal ligament cells into hard tissue-forming cells. Experimental results using a ligature-induced periodontitis mouse model also suggested fluctuations in CGRP expression during periodontal tissue healing, underscoring the vital role of CGRP signaling in alveolar bone recovery. The study results highlight the important role of nerves in the periodontal ligament not only in sensory reception in the periphery, as previously known, but also in periodontal tissue homeostasis and tissue repair processes. [ABSTRACT FROM AUTHOR]