【摘要】 目的　研究老年大鼠下丘脑薄片视交叉上核神经元自发放电的节律性。方法　采用大鼠离体下丘脑薄片记录视交叉上核 (SCN)神经元自发放电的方法 ,观察衰老对SCN神经元自发放电的影响。结果　青年组和老年组大鼠SCN神经元自发放电频率均呈现白昼高、夜间低的节律 ,其高峰出现在CT 6～ 8,青年组频率为 8.30± 1.12Hz,老年组为 6 .5 2± 1.0 5Hz,两组存在显著差异 (P <0 .0 5 ) ;低谷在CT18～ 2 0 ,两组无显著性差异 (P >0 .0 5 )。在白昼 ,青年组平均放电频率为 6 .5 7± 0 .96Hz,老年组为 5 .39± 0 .74Hz,两组存在显著性差异 (P <0 .0 5 ) ;而在夜间 ,两组平均放电频率无显著差异 (P >0 .0 5 )。结论　老年大鼠SCN神经元自发放电的昼夜节律的振荡幅度在衰减。更多还原

【Abstract】 Objective The effects of aging on spontaneous firing of suprachiasmatic nucleus (SCN) neurons in rats is studied.Methods The circadian rhythm of sportaneous firing of suprachiasmatic nucleus neurons was recorded in hypotholanic slices in vitro.Results It was found that,SCN neurons in young and old rats both persisted a circadian rhythm in spontaneous firing rate,which was higher during light phase than during dark phase.The peak of spontaeous firing was at CT 6～8,and there was a significant difference in firing rates (8.30±1.12 Hz in young and 6.52±1.05Hz in old);the trough was at CT18～20,and there was no significant difference.During light phase,the mean firing rates of SCN neurons in old rats (6.57±0.96Hz) was significantly lower than that in young rats (5.39±0.74Hz);but during dark phase,there was no significant difference between two groups.Conclusion These results suggest that oscillating amplitude of circadian rhythm of SCN neurons spontaneous firing attenuates in old rats.更多还原