SD大鼠急性分离下丘脑神经元温度敏感性及其发育过程的研究

THERMO-SENSITIVITY AND ITS DEVELOPMENT OF ACUTELY DISSOCIATED NEURONS OF THE HYPOTHALAMUS IN SD RAT

为探讨出生后SD大鼠急性分离下丘脑神经元的自发性放电及其温度敏感特性,本研究采用电流钳技术对其进行了观察。实验结果表明:在不同鼠龄的神经元中,具有自发性放电神经元的比率没有明显不同;在这些具有自发性放电的神经元中,约30%具有温度敏感性,属于初级热敏神经元,其他属于温度不敏感神经元;同时我们也观察到在神经元的发育过程中,中等斜率的温度不敏感神经元比率逐渐增加,而低斜率的温度不敏感神经元比率则呈现为相反的变化。这些结果与在脑片和培养神经元记录到的结果具有明显的差异。本研究结果可以为神经元温度敏感性的形成机制提供有意义的线索。

Current clamp recordings were conducted in acutely dissociated neurons of SD rat hypothalamus to observe the spontaneous firing and its thermo-sensitivity. The results showed that no obvious changes were found at the ratio of spontaneously firing neurons in the amounts of recording neurons, regardless of birth. Of spontaneous firing neurons, 30% were warm-sensitive and identified as primary warm-sensitive neurons, the remains were temperature-insensitive neurons. During the development from birth, the ratio of moderate-slope insensitive neurons increased gradually but that of low-slope insensitive neurons decreased. These results from acutely dissociated neurons were different from those got from hypothalamic slices and/or cultured neurons significantly. Taken together, these findings provide important insights into the thermo-sensitivity mechanisms of hypothalamic neurons during the critical period of development.