The anterior cingulate cortex (ACC) has recently been proposed as a key player in the representation of itch stimuli. However, to date, little is known about the contribution of specific ACC interneuron populations to itch processing. Using c-Fos immunolabeling and in vivo Ca²⁺ imaging, we reported that both histamine and chloroquine stimuli-induced acute itch caused a marked enhancement of vasoactive intestinal peptide (VIP)-expressing interneuron activity in the ACC. Behavioral data indicated that optogenetic and chemogenetic activation of these neurons reduced scratching responses related to histaminergic and non-histaminergic acute itch. Similar neural activity and modulatory role of these neurons were seen in mice with chronic itch induced by contact dermatitis. Together, this study highlights the importance of ACC VIP⁺ neurons in modulating itch-related affect and behavior, which may help us to develop novel mechanism-based strategies to treat refractory chronic itch in the clinic.
Animals ; Pruritus/physiopathology* ; Vasoactive Intestinal Peptide/metabolism* ; Interneurons/metabolism* ; Gyrus Cinguli/metabolism* ; Mice ; Male ; Mice, Inbred C57BL ; Histamine ; Chloroquine ; Optogenetics ; Mice, Transgenic

Adult ; Asian Continental Ancestry Group ; Biopsy, Needle ; Disease Progression ; Erythema ; complications ; physiopathology ; Female ; Foot Dermatoses ; complications ; diagnosis ; pathology ; Hand Dermatoses ; complications ; diagnosis ; pathology ; Humans ; Immunohistochemistry ; Pemphigus ; diagnosis ; pathology ; Prognosis ; Pruritus ; complications ; physiopathology ; Rare Diseases ; Singapore ; Syndrome

Animals ; Humans ; Pain ; physiopathology ; Pruritus ; physiopathology

In 1905, Henry Head first suggested that transmission of pain-related protopathic information can be negatively modulated by inputs from afferents sensing innocuous touch and temperature. In 1965, Melzak and Wall proposed a more concrete gate control theory of pain that highlights the interaction between unmyelinated C fibers and myelinated A fibers in pain transmission. Here we review the current understanding of the spinal microcircuits transmitting and gating mechanical pain or itch. We also discuss how disruption of the gate control could cause pain or itch evoked by innocuous mechanical stimuli, a hallmark symptom for many chronic pain or itch patients.
Animals ; Humans ; Nerve Net ; pathology ; physiopathology ; Pain ; pathology ; Pruritus ; pathology ; Spinal Cord ; pathology ; Synaptic Transmission ; physiology

In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms.
Animals ; Ceramides/*therapeutic use ; Cholesterol/*therapeutic use ; Dermatitis, Atopic/complications/drug therapy/physiopathology/*veterinary ; Dog Diseases/*drug therapy/etiology/physiopathology ; Dogs ; Emollients/*therapeutic use ; Epidermis/drug effects/physiopathology/ultrastructure ; Fatty Acids, Nonesterified/*therapeutic use ; Female ; Male ; Microscopy, Electron, Transmission/veterinary ; Pruritus/drug therapy/etiology/physiopathology/veterinary ; Republic of Korea ; Ruthenium Compounds/chemistry ; Water Loss, Insensible/drug effects

Adult ; Exanthema ; diagnosis ; drug therapy ; etiology ; physiopathology ; Humans ; Male ; Pruritus ; physiopathology ; Steroids ; administration & dosage ; Treatment Outcome

Abdomen ; physiopathology ; Biomarkers ; Female ; Humans ; Immunoglobulin E ; blood ; Mesothelioma ; diagnosis ; pathology ; Middle Aged ; Outcome Assessment (Health Care) ; Peritoneal Neoplasms ; diagnosis ; pathology ; surgery ; Pruritus ; physiopathology ; surgery ; Radiography, Abdominal

Despite its clinical importance, the underlying central mechanisms of pruritic behaviors are poorly understood. To investigate the role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behaviors in mice, we tested the effect of arcuate nucleus neurons and interscapular brown adipose tissue (IBAT) on itch produced by intradermal injection of chloroquine in the nape of the neck. Our results provide several lines of evidence for an important role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behavior: (1) Intradermal microinjection of chloroquine resulted in a dramatic increase in itch behaviors accompanied by the activation of c-Fos positive neurons in arcuate nucleus; (2) Microinjection of chloroquine significantly increased IBAT temperature in the mice. These findings suggested that chloroquine-induced pruritic behaviors were associated with the activity of nociceptive arcuate nucleus neurons.
Animals ; Arcuate Nucleus of Hypothalamus ; drug effects ; physiopathology ; Chloroquine ; adverse effects ; Male ; Mice ; Mice, Inbred C57BL ; Nociceptors ; drug effects ; physiology ; Pruritus ; chemically induced ; physiopathology

OBJECTIVETo investigate the effects of acupuncture on the morphine-related side effects (nausea, vomiting, itchiness and gastrointestinal disorders) in patients undergoing anesthesia and analgesia and try to find the clinical mechanism of acupuncture.

METHODSPatients scheduled to have transurethral prostatic resection: enrolled in the study (69 patients), characterized as Grade II or III by the American Society of Anesthesiologists physical status classification, were randomly assigned to three groups, 23 patients in each group: the placebo group (control group), non-anesthesia area (NAA) group, and the anesthesia area (AA) group. After spinal anesthesia, all patients received Patients Controlled Epidural Analgesia. The vital signs, bowel sounds, visual analogue scales, itchiness, nausea and vomiting, and time for first exhaust post operation were observed.

RESULTSAltogether, nine cases were eliminated, three in each group. Finally, sixty cases completed this study,: twenty in each group. There was a significant decrease of bowel sounds after morphine spinal anesthesia in the three groups. Compared with the control or AA group, the bowel sound recovered after acupuncture, the incidences of nausea and vomiting, itchiness, and time for first exhaust after operation decreased in the NAA group (P<0.05). There was a significant decrease of the incidence for itchiness in the NAA group compared with

CONCLUSIONSOn the basis of this study, it is obviously seen that acupuncture could: decrease the incidence of morphine-related side effects (nausea and vomiting, itchiness and gastrointestinal disorders) when the spinal cord conduct is normal. However, it decreases only the incidence of itchiness but not for gastrointestinal dysfunction when the spinal cord is blocked.

Acupuncture Therapy ; Aged ; Aged, 80 and over ; Analgesia ; adverse effects ; Analgesia, Epidural ; adverse effects ; Anesthesia, Epidural ; adverse effects ; methods ; Anesthesia, Spinal ; adverse effects ; methods ; Humans ; Intestines ; physiopathology ; Male ; Middle Aged ; Morphine ; administration & dosage ; adverse effects ; Postoperative Complications ; prevention & control ; Postoperative Nausea and Vomiting ; prevention & control ; therapy ; Prostatic Hyperplasia ; physiopathology ; surgery ; Pruritus ; therapy ; Transurethral Resection of Prostate ; rehabilitation ; Treatment Outcome

The temperature-sensitive transient receptor potential (TRP) channels, is also called thermo TRP, including TRPV1, TRPV2, TRPV3, TRPV4, TRPM8 and TRPA1, which are expressed in sensory neurons and non-neuronal cells (e.g.keratinocyte, mast cell) of the skin. Thermo TRP channels are activated/sensitized by physical and chemical mediators, which participate in thermosensation and thermoregulation, so that they are key players in pruritus or pain pathogenesis. Thermo TRP channels are also involved in cutaneous neurogenic inflammation, thus they are regarded as molecular targets for future therapy in skin inflammation, pruritus and pain. In addition, following a basic syntax and molecular substrate of nociception and pruriception established by TRP channels-centered concept, the sensory categories can be distinguished and re-defined. Thermo TRP channels should be taken into account when analyzing the pathogenesis and management of itch or pruritic dermatosis.
Humans ; Inflammation ; metabolism ; physiopathology ; Inflammation Mediators ; physiology ; Pruritus ; metabolism ; Sensory Receptor Cells ; metabolism ; Skin ; innervation ; metabolism ; Thermoreceptors ; metabolism ; Transient Receptor Potential Channels ; metabolism ; physiology