摘要:

Two groups of cats with lesions of the superior colliculi and adjacent pretectal nuclei and two groups of sham‐operated cats were subjected simultaneously to artificial “bright winter” and “dim summer” lighting conditions and their endocrine state determined. Urinary excretion of 11‐hydroxycorticoids, adrenalin, and norad‐renalin were specified with fluorometric techniques, and thyroid function was assessed with an uptake measure of radioiodide and with a rate of release measure of radioiodide‐labelled hormones from the thyroid gland. The results indicated that the cats in the bright winter condition had much higher indices of thyroid and glucocorticoid function. No effect of the lighting schedules on the catecholamines, urinary volume or body weight was detected, and no effect of the lesion was detected. A comparison of these data with our previous longitudinal studies in cats, as well as with the literature on other species, indicates that (1) light is the Zeitgeber for the annual glucocorticoid rhythm; (2) even though light influences the activity of the thyroid gland, it is difficult to consider it as the Zeitgeber because thyroid rhythms do not exhibit annual rhythms; (3) with regard to the role of light in entraining the catecholamines, the results were equivocal, possibly because of the sampling times. Theraison d'etreof biological rhythms is considered, and it is suggested that their provision of order to the temporal milieu may be viewed as a higher order aspect of homeostasis.

ISSN:0022-1945    

DOI:10.1080/09291017509359491

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Four subspecies of deermice(Peromyscus maniculatus)were selected from habitats along a gradient from mesic hardwood forests(gracilis), tall grass prairie(bairdi), short grass prairie(nebrascensis), to desert grassland(labecula)in effort to relate the light preferences of the mice to the habitat of their origin. Six individuals of each subspecies were maintained in dark chambers for 25 days, during which they could turn on a dim light for 30 seconds on ten of these days. Mice from the mesic habitats turned the lights on more frequently (light reinforcement) than mice from xeric habitats. The same subspecies that exhibited light reinforcement when raised in laboratory light conditions failed to show light reinforcement when raised in total darkness. The circadian periodicities also differed significantly among the subspecies. Conclusions drawn from the results were: (1) selection for light is genetically influenced as indicated by subspecific differences, (2) some genotypes are readily modified by environmental light conditions than others, and (3) natural selection in each environment appears to contribute to the degree of genetic fixation or genetic plasticity.

ISSN:0022-1945    

DOI:10.1080/09291017509359492

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The Locomotory activity of the Plains Garter snake was determined under L/D: 12/12 conditions at five constant temperatures and three light intensities during the light period. The snakes were diurnal at low temperatures with nocturnal activity increasing in various amounts at higher temperatures. The different light intensities had relatively small effects on the activity rhythm.

ISSN:0022-1945    

DOI:10.1080/09291017509359493

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

We have established the presence of a rhythm in the activity of 4 enzymes in in‐vitro cell suspensions of human red blood cells. Glucose 6‐phosphate dehydrogenase and glutamate oxaloacetate transaminase demonstrated semicircadian patterns of activity, while acid phosphatese and acetylcholine esterase exhibited circadian activity rhythms. The ratios between the highest to lowest activities varied from 2:1 to 10:1 among the various enzymes. The affinity of glucose 6 phosphate dehydrogenase to its substrate and coenzyme remained constant throughout the cycle. No evidence was obtained for the presence of a soluble inhibitor at the lower levels of the activity. Sonication of hemolysates with low glucose 6 phosphate dehydrogense activity yielded additional activity comparable to that of the peak activity. Sonication of hemolysates from the time of the peak activity did not change the original activity. The observations point to a role of the cell membrane in the biological clock.

ISSN:0022-1945    

DOI:10.1080/09291017509359494

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The studies of Dewey and others indicating the existence of cycle synchronies (i.e., cycles observed in many, entirely different phenomena with the same cycle length and crests occurring at about the same time) suggest a common cause of a world wide or extra‐terrestrial nature. Also many rhythmic or fluctuating phenomena observed in mental processes in man and his behaviour patterns suggest similar world wide exogenous causes. Two possible causes are extensively discussed: (1) world wide geophysical changes in the atmosphere, probably due to solar influences which seem to affect both organic and inorganic colloids in living systems on earth and (2) fluctuations in gravity wave patterns in the universe.

ISSN:0022-1945    

DOI:10.1080/09291017509359495

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The Gastrin content has been estimated in the antral mucosae of male and female rats in different phases of the estrous cycle. Gastrin content appears to be highest in the rats at di‐estrous cycle end lowest in the rats at pro‐estrous. There is not much difference between the gastrin content at estrous and pro‐estrous. The gastrin content in the antral mucosa of male rats is higher than in rats a both estrous and pro‐estrous but it is about the same amount in rats at di‐estrous. The possible role of the circulating sex hormones on the storage of gastrin in the antral mucosa of rats has been discussed.

ISSN:0022-1945    

DOI:10.1080/09291017509359496

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The endogenous activity cycle of the nocturnal bannertail kangaroo rat was investigated. Although bannertail activity is a function of the lunar day as well as the solar day, all ten subjects exhibited free‐running activity periods of solar‐day length; there was no evidence of an endogenous lunar‐day cycle. Animals were provided with a burrow system and a small pseudo‐desert, a laboratory facility in which animal activity data closely resembled measurements taken in the field. Several analytical techniques for quantifying the data were utilized, and one, the mean interval of activity, is recommended to other investigators.

ISSN:0022-1945    

DOI:10.1080/09291017509359497

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0022-1945    

DOI:10.1080/09291017509359490

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor