de Jeu M, Hermes M, Pennartz C
Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research.
Neuroreport. 1998 Nov 16;9(16):3725-9. doi: 10.1097/00001756-199811160-00028.
Perforated patch clamp recordings of neurons in slices of the suprachiasmatic nucleus (SCN) were made in their subjective day and night phases. The spontaneous firing rate and input resistance were significantly higher during the subjective day as compared to the subjective night. In parallel, the membrane potential of neurons recorded at daytime was significantly more depolarized than at nighttime. The day-night differences in membrane potential and input resistance were maintained when spikes and GABA(A) receptor-mediated transmission were blocked by tetrodotoxin and bicuculline, suggesting a cell-autonomous regulation of the circadian modulation of membrane properties. In conclusion, these findings suggest that at least one hyperpolarizing ionic conductance would be open at night and closed during mid-day, when spontaneous firing reaches peak levels in the SCN.
在视交叉上核（SCN）切片中的神经元进行穿孔膜片钳记录，记录时间分别为其主观白天和夜晚阶段。与主观夜晚相比，主观白天的自发放电频率和输入电阻显著更高。同时，白天记录的神经元膜电位比夜间明显更去极化。当用河豚毒素和荷包牡丹碱阻断动作电位和GABA(A)受体介导的传递时，膜电位和输入电阻的昼夜差异依然存在，这表明膜特性的昼夜调节存在细胞自主调控。总之，这些发现表明，至少有一种超极化离子电导在夜间开放，在中午自发发放达到峰值水平时关闭。
