Differentiation of Motor Activity of Normally Active and Hyperactive Boys in Schools: Some Preliminary Results

All non-task-related body movements during school hours were listed in 11 normally active and 12 hyperactive boys. The mean number of movements was 48 +/- 7 per 45 minutes in the normal actives and 79 +/- 16 per 45 minutes in the hyperactives. The rather monotonous increment and decrement of motor activity during the 4-hr registration period was noticed only in hyperactive boys. These results could be a consequence of a circadian rhythm, as there was independence of type of school hours and of teacher personality. The cyclical level of activity in hyperactive boys was sometimes in the range of the normal actives.     

Seasonal covariation of the circadian phases of rectal temperature and slow wave sleep onset

There is a scarcity of well-controlled studies of the seasonal variation in circadian rhythmicity. In the present study, the circadian phase of rectal temperature and the onset of slow wave sleep were studied in a series of twelve 24-h experiments, one each month of the year, for six healthy subjects under controlled conditions in a climatic chamber. In winter, as compared with summer, the average circadian rhythm of rectal temperature was phase delayed by 45 min, and the average onset of slow wave sleep was phase delayed by 40 min. The temporal relationship between the circadian phase of rectal temperature and the timing of slow wave sleep was maintained throughout the year. Habitual rising and retiring times covaried as well. Furthermore, the circadian rhythm of rectal temperature followed the timing of the photoperiod across the year, but had a much smaller range of seasonal variation. Apparently, the seasonal variation in the photoperiodic zeitgeber is largely compensated for by the stabilizing influence of secondary zeitgebers. However, in healthy subjects some effect of photoperiodic variation can still be observed.     

Detailed Diurnal Rhythm of Sensitivity to Melatonin Injections in Turkish Hamsters, Mesocricetus brandti

A diurnal rhythm of sensitivity to exogenous melatonin was defined in adult male Turkish hamsters, Mesocricetus brandti. Melatonin was administered daily by subcutaneous injections (15 micrograms in 0.1 ml 10% ethanolic saline) for 10 weeks in animals exposed to 16 L:8 D. As in golden and Djungarian hamsters, two periods of melatonin sensitivity were identified. The first, in late afternoon, persisted for 6 hr, from 7 hr to 1 hr before lights off. The second period was briefer, of only 2 hr duration in the late night, terminating at the time of lights on. Melatonin injections given during these sensitive periods promoted testicular regression in most animals; melatonin administered at other times of the day was without effect on testicular function in most animals of these groups. Gonadal regression induced by properly timed melatonin injections was rapid, in many groups nearly complete in 6 to 7 weeks. The results are discussed in relation to the function of pineal melatonin in photoperiodic time measurement in hamsters.     

The effect of methamphetamine on serotonin and its metabolite in the suprachiasmatic nucleus: A microdialysis study

Summary The suprachiasmatic nucleus (SCN) has been identified as a major circadian pacemaker. Methamphetamine has been shown to modify the behavior of circadian rhythms. We detected extracellular serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the SCN in freely moving rats, using a microdialysis method, to investigate biochemical effects of methamphetamine in the SCN. Methamphetamine infusion into the SCN dose-dependently increased extracellular 5-HT and decreased extracellular 5-HIAA.     

144例脑血管意外患者死亡时间节律分析

目的　揭示脑血管意外死亡的年节律、月相节律以及昼夜节律 ,为临床及时防治提供时间依据。方法　采用流行病学调查方法收集资料 ,用 χ2 检验及圆形分布法来分析资料。结果　①脑出血死亡时间存在向上半夜集中的昼夜节律 ;②脑梗死死亡时间存在向冬季和下半夜集中的年节律和昼夜节律。结论　脑出血死亡存在昼夜节律 ,脑梗死死亡存在年节律和昼夜节律。     

Xenopus Tadpole Melanophores Are Controlled by Dark and Light and Melatonin Without Influence of Time of Day

Melanophores were studied in tadpoles of the South African clawed toad, Xenopus laevis , during the first week after hatching (stages 46–49) at 25°C. The tadpoles had melanophores with dispersed melanosomes in the light and punctate melanophores in the dark in LD12:12. The melanophores remained punctate in constant dark and the melanosomes remained dispersed in constant light. Lights-out (in the light-time of LD12:12) caused the melanophores to become punctate, which occurred more quickly than the dispersion of melanosomes, which commenced when the lights were turned on (in the dark-time of LD12:12). Melanophores with dispersed melanosomes in tadpoles (in constant light) became punctate in response to a series of melatonin concentrations (0.2–5 ng/ml) in their bathing water irrespective of the time of day melatonin was administered. An image-analysis technique for assessing melanophore responses was tested.     

右归饮择时使用对肾阳虚大鼠生长激素昼夜节律的影响

目的　探讨右归饮择时用药在肾阳虚证治疗中的意义。　方法　采用放免法 ,以肾阳虚大鼠血清生长激素为指标 ,观察右归饮择时用药的疗效。结果　右归饮择时用药对肾阳虚大鼠症状的改善有一定作用 ,并以卯时用药效果较好。结论　右归饮治疗肾阳虚证应当提倡择时用药。     

Age, lens transmittance, and the possible effects of light on melatonin suppression

Recently it has been suggested that a previously undetected, rhodopsin-based, visual pigment, located in some retinal ganglion cells and having a peak sensitivity around 460 nm, may be responsible for light-induced melatonin suppression and, perhaps, maintenance of the circadian rhythm. Using data from the literature, it is shown that, as absorption in the crystalline lens for shorter visible wavelengths increases substantially with age, while the pupil diameter tends to decrease, the effective retinal exposure received under the same ambient lighting conditions by the pigment is almost 10 times lower in an old, as compared with a young, eye. Interestingly, replacement of the old crystalline lens by an intraocular implant restores the exposure to youthful levels. The possible effects of these changes with age on circadian rhythms are discussed.