TASTE RESPONSES IN THE GREATER SUPERFICIAL PETROSAL NERVE - SUBSTANTIAL SODIUM-SALT AND AMILORIDE SENSITIVITIES DEMONSTRATED IN 2 RAT STRAINS

A great quantity of research has focused on neural responses of the ch orda tympani nerve (CT) to taste stimuli. This report examined salt an d sugar sensitivity of the greater superficial petrosal nerve (GSP) an d the effect of amiloride on these neural responses. In addition to Sp rague-Dawley (SD) rats that have CT responses typical of most rat stra ins, we included Fischer 344 (F344) rats whose CT responses to sodium chloride (NaCl) are higher than those of other strains. After a stimul ation series in which water served as the rinse, a series of stimuli w as presented in 100 mu M amiloride. The GSP was highly responsive to N aCl, sodium acetate (NaAc), ammonium chloride, and sucrose; NaCl and N aAc responses were strongly suppressed by amiloride. Relative response s to NaCl were significantly higher in F344 than in SD rats. In summar y, the GSP is highly sensitive to salt and sugar stimulation, and pala tal taste receptors have a considerable degree of amiloride sensitivit y.