Capsaicin causes selective damage to type I synaptic glomeruli in rat substantia gelatinosa.
Most type I synaptic glomeruli were lacking in adult rats given capsaicin neonatally, while topical cord applications of the drug caused dense degeneration of numerous CI- and very few CIIa-terminals. These data give support to the presumable origin of CI-terminals from unmyelinated primary afferents and suggest that CIIa-terminals may belong to small myelinated afferents.
D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000633:toxicity*; D008854:Microscopy, Electron; D051381:Rats; D013116:Spinal Cord / Q000648:ultrastructure*; D013376:Substantia Gelatinosa / Q000187:drug effects / Q000648:ultrastructure*; D013569:Synapses / Q000187:drug effects / Q000648:ultrastructure*
D002211:Capsaicin