REGENERATED TASTE BUDS AND SALT TASTE RESPONSES IN THE RAT CHORDA TYMPANI NERVE

鼓索神经（CT）切断后，味蕾退化消失。然而，随着时间的推移，味蕾在切断的神经再生后重新出现在菌状乳头中。在本研究中，恢复钠盐反应再生CT单侧横断鼓索舌神经在成年大鼠进行了调查，使用阿米洛利，钠离子通道阻滞剂。在神经切断后28天，首次获得来自再生CT的味觉反应。相对于0.5 M NH_4CI响应计算所有响应的比率。再生CT对0.3-0.5 M NaCl和乙酸钠的响应的相对幅度在第28-35天约为0.6，在第36-45天约为0.8。阿米洛利处理的结果显示，再生CT中的阿米洛利敏感成分在28-35天很小，此后突然增加。然而，阿米洛利不敏感的组件不相关的时间后，横断的神经，当钠盐的反应的幅度表示相对于0.5 M NH_4Cl。镧离子，一种紧密连接阻断剂，在2.5 mM，并没有影响阿米洛利不敏感的组件在手术大鼠的再生CT和对照大鼠的完整CT。这表明，味觉细胞之间的细胞旁通路不参与大鼠阿米洛利不敏感的钠味觉接收。

After chorda tympani nerve (CT) transection, taste buds degenerate and disappear. Given time, however, taste buds reappear in fungiform papillae after regeneration of the cut nerve. In the present study, recovery of Na salts response from the regenerated CT after unilateral transection of the chorda tympanilingual nerve in the adult rats was investigated using amiloride, a sodium ion channel blocker. Taste responses from the regenerated CT were first obtained 28 days after transection of the nerve. Ratios for all responses were calculated relative to the 0.5 M NH_4CI response. The relative magnitude of the responses to 0.3-0.5 M NaCl and Na acetate from the regenerated CT were about 0.6 on days 28-35, and were about 0.8 on days 36-45. Results of amiloride treatment revealed that amiloride-sensitive components in the regenerated CT was small on days 28-35 and abruptly increase thereafter. However, amiloride-insensitive components were not related to times after transection of the nerve, when the magnitude of the responses to Na salts was expressed relative to that to 0.5 M NH_4Cl. La ions, a tight junction blocker, at 2.5 mM did not affect amilorideinsensitive components in both the regenerated CT in surgery rats and the intact CT in control rats. This suggests that paracellular pathways between taste cells are not involved in amiloride-insensitive sodium taste reception in the rat.