Lm. Phillips et Dl. Hill, NOVEL REGULATION OF PERIPHERAL GUSTATORY FUNCTION BY THE IMMUNE-SYSTEM, American journal of physiology. Regulatory, integrative and comparative physiology, 40(4), 1996, pp. 857-862
Soon after adult rats receive unilateral chorda tympani nerve section
in combination with dietary sodium restriction, neural taste responses
recorded from the intact, contralateral chorda tympani nerve are subs
tantially reduced. We hypothesized that the immune system is compromis
ed in sodium-restricted rats, which leads to functional alterations in
the peripheral taste system after neural injury. Here, immune functio
n was stimulated with a systemic injection of lipopolysaccharide (LPS)
, and neurophysiological responses were recorded from the uncut chorda
tympani 4-10 days after nerve section to determine if normal sodium s
ensitivity was restored. Rats receiving nerve section, dietary sodium
restriction, and LPS exhibited normal sodium responses. In intact rats
, injection of LPS alone or LPS injection combined with sodium restric
tion had no effect on taste responses to sodium stimuli. Surprisingly,
combining nerve section, LPS injection, and maintenance of rats on a
normal diet induced supersensitive responses to sodium. These findings
are the first to demonstrate that the immune system can regulate peri
pheral gustatory function.