Effects of glossopharyngeal nerve transection on central and peripheral cytokines and serum corticosterone induced by localized inflammation.

Bilateral transection of the glossopharyngeal nerves (GLOx) disrupts the immune-to-brain communication from the posterior oral cavity. The current report tested whether this effect is due to the afferent (sensory) or efferent (parasympathetic motor) components of the nerve. Injection of lipopolysaccharide (LPS) into the soft palate (ISP) of GLOx or sham-operated (SHAM) rats increased the circulating levels of interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1ra) and corticosterone (CORT), as well the hypothalamic content of IL-1beta; no difference in circulating levels and hypothalamic content was found between GLOx and SHAM at 2 and 4.5 h after LPS injection. These results indicate that glossopharyngeal neural efferents do not mediate the effects of GLOx on the immune-to-brain communication.