Bowers C W, Zigmond R E
J Physiol. 1982 Sep;330:279-96. doi: 10.1113/jphysiol.1982.sp014341.
The activity of the pineal enzyme arylamine: N-acetyltransferase (NAT) was determined following direct stimulation of the preganglionic or post-ganglionic nerves of the superior cervical ganglia. 1. Stimulation of the preganglionic trunks at 10 c/sec during the day or night was sufficient to increase NAT activity approximately 50-fold, to levels comparable to those observed at night in the intact animal. The time course of this effect of nerve stimulation differed between day and night. 2. The responses of pineal NAT to certain frequencies of stimulation were similar for preganglionic and post-ganglionic stimulation. In both cases the responses to stimulation at 5 c/sec appeared to be maximal, 10 c/sec causing no further increase. However, at 10 c/sec, stimulation was more effective post-ganglionically than preganglionically. 3. Various patterns of preganglionic stimulation, having the same average frequency, differed in their ability to increase the activity of NAT. Some, though not all, of these differences between patterns were observed during post-ganglionic stimulation. 4. Unilateral stimulation of the preganglionic nerves produced an increase in NAT activity that was less than half the increase produced by bilateral stimulation, suggesting that the innervation from the two ganglia interact within the pineal gland. 5. These data indicate that changes in the firing rates of sympathetic nerves innervating the pineal gland, within the range of frequencies typically observed for sympathetic neurones, would be sufficient to account for the circadian rhythm in NAT activity observed in the intact rat. Changes in the over-all pattern of sympathetic activity, in addition to changes in the total number of stimuli, could play a significant role in the pineal response.
在直接刺激颈上神经节的节前或节后神经后，测定了松果体酶芳胺：N - 乙酰基转移酶（NAT）的活性。1. 白天或夜晚以10次/秒的频率刺激节前干，足以使NAT活性增加约50倍，达到与完整动物夜间观察到的水平相当。神经刺激这种效应的时间进程在白天和夜晚有所不同。2. 松果体NAT对特定刺激频率的反应，节前和节后刺激相似。在这两种情况下，对5次/秒刺激的反应似乎最大，10次/秒的刺激不会进一步增加。然而，在10次/秒时，节后刺激比节前刺激更有效。3. 具有相同平均频率的各种节前刺激模式，在增加NAT活性的能力上有所不同。这些模式之间的一些差异（并非全部）在节后刺激时也能观察到。4. 单侧刺激节前神经导致NAT活性增加，不到双侧刺激所产生增加量的一半，这表明来自两个神经节的神经支配在松果体内相互作用。5. 这些数据表明，在交感神经元通常观察到的频率范围内，支配松果体的交感神经放电率的变化，足以解释完整大鼠中观察到的NAT活性的昼夜节律。除了刺激总数的变化外，交感活动总体模式的变化可能在松果体反应中起重要作用。
