Age related decreases in neural sensitivity to NaCl in SHR-SP
Age related decreases in neural sensitivity to NaCl in SHR-SP
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DOI：
10.1292/jvms.65.313
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发表时间：
2003-03-01
影响因子：
1.2
通讯作者：
Furukawa, Y
中科院分区：
文献类型：
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作者：
Osada, K;Komai, M;Furukawa, Y
为了确定年轻和年老大鼠的神经生理味觉反应是否不同，对支配前舌味蕾的整个鼓索神经进行了记录。对两个年龄组的 SHR-SP（易中风自发性高血压大鼠）进行了研究。化学刺激包括单一浓度的 250 mM NH4Cl、100 mM NaCl、100 mM KCl、500 mM 蔗糖、20 mM 盐酸奎宁、10 mM HCl、10 mM 谷氨酸钠 (MSG)、10 mM L-谷氨酸 (L-Glu) 和 NaCl 浓度系列。神经反应的幅度（反应比）是通过将综合反应的幅度除以之前的自发活动的幅度来计算的。在两个年龄段都获得了对所有化学物质的显着神经反应。对KCl、蔗糖、盐酸奎宁、HCl、味精（MSG）和谷氨酸（Glu）的反应不随年龄而变化，但对氯化钠的反应却显着下降。氯化钠的响应/浓度函数的轮廓随年龄的不同而不同。特别是，老年 SHR-SP 对浓度高于 100 mM NaCl 的溶液的反应明显弱于年轻的 SHR-SP。我们还观察到，老年大鼠的 SHR-SP 舌头上的阿米洛利治疗恢复速度比年轻大鼠更快，这表明味觉细胞上的钠特异性通道存在一些功能差异。这些结果表明，与年轻的 SHR-SP 相比，老化的 SHR-SP 区分较高浓度的 NaCl 溶液的能力可能较差。
To determine whether neurophysiological taste responses of young and old rats are different, recordings were made from the whole chorda tympani nerve which innervates taste buds on the anterior tongue. SHR-SP (Stroke-Prone Spontaneously Hypertensive Rats) in two age groups were studied. Chemical stimuli included single concentrations of 250 mM NH4Cl, 100 mM NaCl, 100 mM KCl, 500 mM sucrose, 20 mM quinine-hydrochloride, 10 mM HCl, 10 mM monosodium glutamate (MSG), 10 mM L- glutamic acid (L-Glu) and an NaCl concentration series. The magnitude of the neural response (response ratio) was calculated by dividing the amplitude of the integrated response by the amplitude of the spontaneous activity that preceded it. Substantial neural responses to all chemicals were obtained at both ages. The responses to KCl, sucrose, quinine-hydrochloride, HCl, monosodium glutamate (MSG) and glutamic acid (Glu) did not change with age, but the response to NaCl did decrease significantly. The profile of the response/concentration function for NaCl differed with age. In particular, the responses to solutions more concentrated than 100 mM NaCl were significantly weaker in aged than in young SHR-SPs. We also observed that recovery from amiloride treatment on the tongue of SHR-SPs was faster in aged rats than in young ones, suggesting that there is some functional difference in the sodium-specific channels on the taste cell. These results suggest that aged SHR-SP may be less able than young SHR-SPs to discriminate among higher concentrations of NaCl solutions.