Immune-induced flavor aversion in mice: Modification by neonatal capsaicintreatment

Objective: This study was designed to evaluate the role of c-sensitive fibe rs in the establishment of immune-induced flavor aversion in mice. Methods: Mice were treated neonatally with capsaicin in order to destroy c-sensitiv e fibers; after such treatment, adult animals, immunized or not with ovalbu min, were submitted to a two-bottle preference test, with a choice between water and a sweetened egg white solution. Results. Neonatal capsaicin treat ment was unsuccessful in preventing the development of immune-induced avers ion to the sweetened solution containing the antigen. Nonetheless, amongst immunized mice, those which had been previously treated with capsaicin show ed a significant increment in the preference for the sweetened egg white so lution. Furthermore, our data showed that neonatal capsaicin treatment did not interfere with either IgG1 or IgE production. Conclusion: The present r esults suggest that c-sensitive fibers have a role in the transmission of t he signals generated by this immune response to the central nervous system, thus contributing to the development of a flavor aversion in mice. Copyrig ht (C) 2001 S. Karger AG, Basel.