Shibata S, Oomura Y, Hattori K, Kita H
Brain Res. 1984 Jun 4;302(1):83-9. doi: 10.1016/0006-8993(84)91287-3.
Stimulation of the optic nerve evoked two positive waves (P1 and P2) with short latencies and a following large negative wave (N) in the suprachiasmatic nucleus (SCN) of hypothalamic slice preparations. The conduction velocities of the P1, P2 and N waves were assumed to be 2.9 m/s, 0.5 m/s and 0.4 m/s, respectively. The N wave disappeared in low Ca2+ medium and all responses disappeared when TTX was added to the medium at a concentration of 10(-6) M. The results indicate that the P1 and P2 waves were responses of the optic nerve in the SCN and the N wave was that of SCN neurons. Following optic nerve stimulation 15 out of 212 single SCN neurons were excited; 10 were excited then inhibited, 14 were excited followed by rhythmic oscillation, and 4 were inhibited. The results demonstrate neuronal projections from the optic nerve to the SCN, and suggest that the major role of the excitatory influence on SCN neurons is responsible for the elevation of neuronal activity in the SCN during the daytime.
对视神经的刺激在下丘脑切片制备物的视交叉上核（SCN）中诱发了两个潜伏期较短的正向波（P1和P2）以及随后的一个大的负向波（N）。假定P1、P2和N波的传导速度分别为2.9米/秒、0.5米/秒和0.4米/秒。N波在低钙培养基中消失，当向培养基中加入浓度为10^(-6) M的河豚毒素（TTX）时，所有反应均消失。结果表明，P1和P2波是SCN中视神经的反应，而N波是SCN神经元的反应。在视神经刺激后，212个单个SCN神经元中有15个被兴奋；10个先兴奋然后被抑制，14个兴奋后出现节律性振荡，4个被抑制。结果证明了从视神经到SCN的神经元投射，并表明对视交叉上核神经元的兴奋性影响的主要作用是在白天期间负责视交叉上核中神经元活动的升高。
