Welsh D K, Logothetis D E, Meister M, Reppert S M
Laboratory of Developmental Chronobiology, Massachusetts General Hospital, Boston 02114, USA.
Neuron. 1995 Apr;14(4):697-706. doi: 10.1016/0896-6273(95)90214-7.
Within the mammalian hypothalamus, the suprachiasmatic nucleus (SCN) contains a circadian clock for timing of diverse neuronal, endocrine, and behavioral rhythms. By culturing cells from neonatal rat SCN on fixed microelectrode arrays, we have been able to record spontaneous action potentials from individual SCN neurons for days or weeks, revealing prominent circadian rhythms in firing rate. Despite abundant functional synapses, circadian rhythms expressed by neurons in the same culture are not synchronized. After reversible blockade of neuronal firing lasting 2.5 days, circadian firing rhythms re-emerge with unaltered phases. These data suggest that the SCN contains a large population of autonomous, single-cell circadian oscillators, and that synapses formed in vitro are neither necessary for operation of these oscillators nor sufficient for synchronizing them.
在哺乳动物的下丘脑内，视交叉上核（SCN）包含一个生物钟，用于调节各种神经元、内分泌和行为节律的时间。通过将新生大鼠SCN的细胞培养在固定的微电极阵列上，我们能够连续数天或数周记录单个SCN神经元的自发动作电位，揭示出放电频率中显著的昼夜节律。尽管存在丰富的功能性突触，但同一培养物中神经元表达的昼夜节律并未同步。在持续2.5天的神经元放电可逆性阻断后，昼夜放电节律以未改变的相位重新出现。这些数据表明，SCN包含大量自主的单细胞昼夜振荡器，并且体外形成的突触对于这些振荡器的运作既不是必需的，也不足以使它们同步。
