Pain signal pathways in central nervous system

Pain signal pathways in the central nervous system comprise intricate networks that transmit nociceptive information from peripheral sensory neurons through spinal cord laminae I-V into higher brain centers responsible for perception. These include myelinated Aδ fibers transmitting fast sharp acute signals primarily projecting to lamina I/III, unmyelinated C-fibers conveying slow dull aching stimuli mainly projecting to lamina II. The dorsal horn acts as an integration hub where excitatory inputs are modulated by local interneurons releasing GABA/glycine inhibitory transmitters alongside descending modulatory influences originating from brainstem regions such as periaqueductal gray, rostral ventral medulla, locus coeruleus. Key molecular players involve opioid μ-receptors expressed on C-fiber terminals which can be activated endogenously or pharmacologically for analgesia. Other important modulators include α2 adrenergic receptors mediating noradrenaline effects; cannabinoid CB1 receptors; serotonergic systems via raphe nuclei projections; various ion channels controlling neuronal excitability; inflammatory mediators like prostaglandins contributing to peripheral/central sensitization. Dysregulation leads to pathological states characterized by hyperalgesia/allodynia seen in neuropathic/inflammatory chronic pains. Understanding this complex interplay provides avenues for targeted therapies aiming at specific molecules/receptors within these networks[1][2][3][4]. In summary, "Pain signal pathways in central nervous system" represents a broad physiological concept encompassing multiple validated drug targets but is not itself a singular molecular entity suitable for canonical naming or direct therapeutic targeting without specifying component molecules/receptors individually.

Other names

Nociceptive pain pathwaysCentral pain processing circuitsDescending and ascending pain modulatory systems

Drugs act by: Inhibiting neurotransmitter release or receptor activation at primary afferent terminals or spinal dorsal horn neurons; Enhancing descending inhibitory control via brainstem nuclei like periaqueductal gray and rostral ventral medulla; Reducing inflammatory mediator production/sensitization at peripheral nerve endings; Modulating ion channel activity affecting neuronal excitability.