Cutaneous sensory nerve signaling related to pain and itch

Cutaneous sensory nerve signaling related to pain and itch is a complex physiological process involving the detection and transmission of noxious and pruritic stimuli from the skin to the central nervous system. This signaling is primarily mediated by specialized primary afferent neurons, including unmyelinated C-fibers and thinly myelinated A-delta fibers, which express a variety of specialized receptors and ion channels [Julius, 2013, Science]. Key molecular components include transient receptor potential (TRP) channels like TRPV1 and TRPA1, which act as polymodal sensors, and voltage-gated sodium channels such as Nav1.7, Nav1.8, and Nav1.9, which are essential for action potential generation and propagation [Dib-Hajj et al., 2013, Nat Rev Neurosci]. Itch-specific signaling often involves Mas-related G-protein coupled receptors (MRGPRs) and the release of neuropeptides like gastrin-releasing peptide (GRP) [Dong et al., 2001, Cell]. Dysregulation of these pathways is a hallmark of chronic pain and pruritus conditions, such as neuropathic pain, atopic dermatitis, and psoriasis [Lay & Dong, 2020, Annu Rev Neurosci]. Pharmacological intervention targets these components through various mechanisms, including ion channel blockade (e.g., lidocaine), receptor antagonism (e.g., CGRP antagonists), or desensitization (e.g., capsaicin) to alleviate symptoms and restore normal sensory function. Therapeutic challenges include maintaining protective sensations while blocking pathological signaling and managing systemic side effects like dizziness or thermal dysregulation [Gavva et al., 2008, Pain].

Other names

Somatosensory signalingNociceptive and pruriceptive signalingCutaneous nociceptionCutaneous pruriceptionPeripheral sensory signaling

Inhibition of voltage-gated sodium channels, antagonism of CGRP receptors, desensitization of TRPV1 channels, antagonism of NK1 receptors, activation of kappa opioid receptors, and inhibition of IL-4/IL-13 signaling.