Marshall L, Mölle M, Fehm H L, Born J
Department of Clinical Neuroendocrinology, Medical University of Lübeck, Germany.
Eur J Neurosci. 1998 Mar;10(3):1167-78. doi: 10.1046/j.1460-9568.1998.00131.x.
The direct current (DC) potential recorded from the scalp of awake humans has been considered a reflection of general changes in cortical excitability. This study examined DC potential shifts in humans during a night of continuous sleep. Standard polysomnographic recordings and skin temperature were measured simultaneously. Contrary to expectations, average DC potential level indicated higher negativity during nonrapid eye movement (NREM) sleep than REM sleep and wakefulness. Moreover, a dynamic regulation of the DC potential level was revealed in association with the NREM-REM sleep cycle comprising four successive phases: (i) a steep 'NREM-transition-negative shift' during the initial 10-15 min of the NREM sleep period; (ii) a more subtle 'NREM-positive slope' during the subsequent NREM sleep period; (iii) a steep 'REM-transition-positive shift' starting shortly prior to the REM sleep period, and (iv) a 'REM-negative slope', characterizing the remaining greater part of the REM sleep period. DC potential changes were only weakly related to changes in slow-wave activity (r2 < 0.18). The NREM-negative slope and REM-positive slope could reflect, respectively, gradually increasing and decreasing cortical excitability resulting from widespread changes in the depolarization of apical dendrites. In contrast, the NREM-transition-negative shift and the REM-transition-positive shift may reflect the progression and retrogression, respectively, of a long-lasting hyperpolarization in deeply lying neurons.
从清醒人类头皮记录到的直流（DC）电位被认为是皮层兴奋性总体变化的反映。本研究检测了人类在连续睡眠一夜期间的直流电位变化。同时测量了标准多导睡眠图记录和皮肤温度。与预期相反，平均直流电位水平显示在非快速眼动（NREM）睡眠期间比快速眼动（REM）睡眠和清醒时更负。此外，还揭示了直流电位水平与包括四个连续阶段的NREM-REM睡眠周期相关的动态调节：（i）在NREM睡眠期开始的最初10-15分钟内出现陡峭的“NREM过渡负向偏移”；（ii）在随后的NREM睡眠期出现更细微的“NREM正向斜率”；（iii）在REM睡眠期前不久开始出现陡峭的“REM过渡正向偏移”，以及（iv）“REM负向斜率”，其特征是REM睡眠期的其余大部分时间。直流电位变化与慢波活动变化的相关性较弱（r2 < 0.18）。NREM负向斜率和REM正向斜率可能分别反映了由于顶端树突去极化的广泛变化导致的皮层兴奋性逐渐增加和降低。相反，NREM过渡负向偏移和REM过渡正向偏移可能分别反映了深层神经元中持久超极化的进展和消退。
