Reduced responsiveness of locus coeruleus neurons to cutaneous thermal stimuli in capsaicin-treated rats.
Recent electrophysiological experiments have shown that brain norepinephrine (NE) neurons in the locus coeruleus (LC) are activated by cutaneous thermal stimuli of both non-noxious and noxious character. In the present study the LC neuronal response to thermal stimuli was used to evaluate cutaneous thermal sensitivity in capsaicin-treated rats, a treatment that is described to cause impaired thermoregulation. Capsaicin treatment, of neonates as well as of adult rats, caused a reduced responsiveness of brain LC neurons to thermal stimuli. The results suggest that a reduction in peripheral thermal afferent transmission may be one mechanism underlying the capsaicin-induced thermoregulatory dysfunction.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001833:Body Temperature Regulation / Q000187:drug effects*; D002211:Capsaicin / Q000494:pharmacology*; D008125:Locus Coeruleus / Q000502:physiology*; D008297:Male; D009638:Norepinephrine / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012867:Skin / Q000294:innervation*; D009435:Synaptic Transmission / Q000187:drug effects; D013697:Thermosensing / Q000187:drug effects*
D002211:Capsaicin; D009638:Norepinephrine