ISSN : 1226-9654
The present study was performed to investigate the characteristics of sensory information produced by capsaicin in the tongue. Activities of the chorda tympani(CN) and lingual nerves(LN) were recorded while taste stimuli and capsaicin were being applied topically, and capsaicin and algesics were being injected intra-arterially to the tongue of cats anesthetized with α-chloralose. Responses of the CN fibers to topically applied capsaicin were correlated with those to taste stimuli and intre-arterially injected algesics. Responses of the CN fibers to intra-arterially applied capsaicin were correlated with those to topically applied capsaicin and intra-arterially injected algesics. Responses of the LN fibers to topically applied capsaicin were correlated with those to intra-arterially injected algesics. Responses of the LN fibers to intra-arterially aplied capsaicin were correlated with those to topically applied capsaicin and intra-arterially injected algesics. These results suggest that capsaicin provoke taste as well as pain sensation in the tongue. Taste information produced by capsaicin is conveyed to the brain via the CN and pain information via the LN. However, the possibility that pain information may be conveyed via the CN can not be excluded.