Silver R, LeSauter J, Tresco P A, Lehman M N
Department of Psychology, Barnard College and Columbia University, New York, New York 10027, USA.
Nature. 1996 Aug 29;382(6594):810-3. doi: 10.1038/382810a0.
The mammalian suprachiasmatic nuclei (SCN) transmit signals to the rest of the brain, organizing circadian rhythms throughout the body. Transplants of the SCN restore circadian activity rhythms to animals whose own SCN have been ablated. The nature of the coupling signal from the grafted SCN to the host brain is not known, although it has been presumed that functional recovery requires re-establishment of appropriate synaptic connections. We have isolated SCN tissue from hamsters within a semipermeable polymeric capsule before transplantation, thereby preventing neural outgrowth but allowing diffusion of humoral signals. Here we show that the transplanted SCN, like neural pacemakers of Drosophila and silkmoths, can sustain circadian activity rhythms by means of a diffusible signal.
哺乳动物的视交叉上核（SCN）向大脑其他部分传递信号，从而协调全身的昼夜节律。将SCN移植到自身SCN已被切除的动物体内，可恢复其昼夜活动节律。尽管推测功能恢复需要重新建立适当的突触连接，但来自移植的SCN与宿主大脑的耦合信号的性质尚不清楚。我们在移植前从仓鼠体内分离出SCN组织，并将其置于半透性聚合物胶囊中，从而阻止神经生长，但允许体液信号扩散。在此我们表明，移植的SCN与果蝇和蚕蛾的神经起搏器一样，能够通过一种可扩散的信号维持昼夜活动节律。
