[Verse 1] Skin meets stimulus, the story starts at the edge Aδ and C fibers posted on the ledge Aδ is myelinated, sharp and fast like a blade C fiber unmyelinated, slow burn, second wave TRPV1 opens when the capsaicin bites Nav one-point-seven gates the sodium spike Nav one-point-eight keeps the current alive ASICs reading acid, telling cells to survive Transduction, transmission — the periphery's alive Converting thermal and mechanical into electrical drive [Chorus] El dolor tiene un camino, sube por la espina Nociceptores firing, dorsal horn machina A-delta, fibra C, canales que abren Gate control, señales que se abren y caben Wide dynamic range, the laminae know the score El cuerpo tiene el antídoto — endogenous and more [Verse 2] Dorsal horn is where the signal hits the gate Laminae one and two — substantia gelatinata Wide-dynamic-range neurons stack the inputs up Innocuous to noxious — they amplify the cup Rexed laminae organized like floors in a tower Each one processing signals, each one holding power Glutamate and substance P flood the synaptic cleft Wind-up phenomenon — the sensitivity is left Gate control said interneurons hold the latch Aβ fibers inhibit — Melzack and Wall's dispatch Modern revisions add descending lanes on top The gate ain't just mechanical — neurochemistry won't stop [Chorus] El dolor tiene un camino, sube por la espina Nociceptores firing, dorsal horn machina A-delta, fibra C, canales que abren Gate control, señales que se abren y caben Wide dynamic range, the laminae know the score El cuerpo tiene el antídoto — endogenous and more [Verse 3] Spinothalamic tract running contralateral and clean Crosses at the cord level, localization machine Spinoreticular hits the brainstem, stirs the arousal Spinomesencephalic — PAG gets the causal Thalamus relays it to somatosensory cortex Localizing pain with anatomical vortex Insula encodes the interoceptive sting Anterior cingulate carries the suffering Prefrontal cortex colors it with meaning and dread The pain matrix concept — debated but widespread Critics say no region is specific to pain's call It's a dynamic network — contextual, not a hall [Bridge] PAG to RVM — descendiendo la señal Locus coeruleus dropping noradrenaline down the canal Serotonergic pathways — dual-edged, can inhibit or excite Endogenous opioids — enkephalin locking mu-receptor tight Beta-endorphin, dynorphin — the pharmacy we own Descending modulation means the brain edits what is shown [Chorus] El dolor tiene un camino, sube por la espina Nociceptores firing, dorsal horn machina A-delta, fibra C, canales que abren Gate control, señales que se abren y caben Wide dynamic range, the laminae know the score El cuerpo tiene el antídoto — endogenous and more [Outro] Nociception isn't pain — perception takes a cortex Sensation plus emotion plus cognition form the vortex From TRPV1 to the prefrontal throne El dolor es tuyo — but the pathway can be owned
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