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991.
The present study examined the effects of photoperiod on spatial and temporal memory in adult Sprague-Dawley rats that were conceived and reared in different day lengths, i.e., short day (SD-8:16 light/dark) and long day (LD-16:8 light/dark). Both male and female LD rats demonstrated increased spatial memory capacity as evidenced by a lower number of choices to criterion in a 12-arm radial maze task relative to the performance of SD rats. SD rats also demonstrated a distortion in the content of temporal memory as evidenced by a proportional rightward shift in the 20 and 60 s temporal criteria trained using the peak-interval procedure that is consistent with reduced cholinergic function. The conclusion is that both spatial and temporal memory are sensitive to photoperiod variation in laboratory rats in a manner similar to that previously observed for reproductive behaviour. 相似文献
992.
Houdelier C Bertin A Guyomarc'h C Richard MA Lumineau S 《Chronobiology international》2007,24(2):235-252
Reproduction is generally controlled by important temporal constraints involving complex adaptive mechanisms. Birds, in temperate zones, present marked breeding seasonality as well as marked daily organization of reproductive behavior, especially laying. Intra-specific variability and determinants of this pattern have been investigated mainly in domestic non-passerine birds. The present study analyzed the daily temporal organization of laying in a free-living species, the European starling, Sturnus vulgaris. Breeding in a starling colony was monitored for five consecutive years using a non-invasive method (infrared video camera) to precisely estimate laying times. European starlings present a marked daily laying rhythm, ovipositions occurring only during a morning species-specific temporal window. Inside this laying window, time intervals between successive eggs varied greatly among females. Contrary to many species, the light/dark cycle did not appear to control laying time in European starlings, but daily variations of the ultraviolet composition of the solar spectrum appeared to be a possible Zeitgeber of this behavior. 相似文献
993.
Angela J. Pereira-Morales Leandro P. Casiraghi Ana Adan 《Chronobiology international》2019,36(2):225-236
Among the factors that contribute to the onset and maintenance of depressive disorders, rhythmicity of symptoms and consumption of caffeine have recently gained attention. The current study aimed to examine the differential rhythmicity of relevant variables in a sample of young participants, considering the presence of depressive symptomatology and the frequency of caffeinated drinks consumption. A significant 24-hour differential rhythmicity of mood, cognitive and physiological variables was found indicating an evening peak pattern in the participants with depressive symptoms. Interestingly, caffeinated drinks consumption was differentially associated with self-perceived peaks, according to the presence of depressive symptomatology. Our findings are among the first reports about the potential association of the 24-hours rhythmicity of relevant mood-related variables, depressive symptoms, and caffeine intake. These results support the view that the identification of risk factors for depression, and the application of novel measurements and analysis methods in the development of new preventive strategies should be a public health priority. 相似文献
994.
The Chinese mitten crab, Eriocheir sinensis is a successful invader. Whilst non-breeding adult E. sinensis have been associated with the destruction of riverbanks, little is known about the ecology of this species in its invaded
areas. This is especially true of the juveniles which are a key migratory stage. Intertidal surveys along the Thames estuary
indicated an increase in the population since the 1990s. Juvenile E. sinensis were abundant in the sampled upper tidal region of the Thames, refuging under boulders in the intertidal at low tide. Seasonal
differences in sampled populations were observed, with a significantly lower abundance of crabs found during winter compared
to summer. Mark-recaptures indicated movement in the intertidal occurring during high tide, with an influx of new crabs evident
after a single tidal cycle. Endogenous rhythms were also apparent, with peaks in activity occurring corresponding with night-time
high tide conditions. E. sinensis juveniles can successfully exclude similar sized native Carcinus maenas from shelters in the laboratory, regardless of which species originally inhabited the shelter. This may have implications
for native estuarine Carcinus populations, which can rely on such intertidal shelters for refuges. 相似文献
995.
Lorenzo Pérez-Rodríguez Carlos Alonso-Alvarez Mónica Martínez-Haro Javier Viñuela 《European Journal of Wildlife Research》2008,54(1):21-26
Blood biochemical parameters may provide useful information about the physical condition of the individual, making them a
useful tool in ecological studies. However, to avoid biases, factors affecting circulating levels of plasma metabolites must
be investigated. In this paper, we analyse the effect of daytime sampling hour on seven plasma metabolites in adult red-legged
partridges (Alectoris rufa) with free access to food during the breeding season. We found that sampling hour affected circulating levels of glucose
and triglycerides but not those of cholesterol, total protein, uric acid, urea or albumin. A sex effect was found only for
glucose, uric acid, urea and triglycerides. Repeated sampling affected all the parameters studied. These results suggest that
the effect of sex, sampling hour and repeated sampling should be carefully controlled for (methodologically or by statistical
procedures) to avoid undesirable sources of error at least in some blood parameters. 相似文献
996.
997.
Hofman M. A. 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2003,189(11):823-831
The mammalian suprachiasmatic nucleus is the principal component of a neural timing system implicated in the temporal organization of circadian and seasonal processes. The present study was performed to analyze the circadian profiles of two major neuropeptidergic cell groups in the human suprachiasmatic nucleus. To that end the brains of 40 human subjects collected at autopsy were investigated. The populations of arginine vasopressin- and vasoactive intestinal polypeptide-expressing neurons, located in the shell and core of the suprachiasmatic nucleus, respectively, showed marked circadian rhythms with an asymmetrical, bimodal waveform. Time series analysis revealed that these circadian cycles in neuronal activity could be described by a composite model consisting of a nonlinear periodic function, with mono- and diphasic cycles. The findings suggest that the 24-h biosynthesis of neuropeptides in the human suprachiasmatic nucleus, being part of the neural output pathway of the clock, is driven by a complex pacemaker system consisting of coupled nonlinear oscillators, in accordance with a multioscillator model of circadian timekeeping.Abbreviations AIC Akaikie's information criterion - ARMA autoregressive moving average - AVP arginine vasopressin - c-fos immediate early gene - Per period gene - SCN suprachiasmatic nucleus - VIP vasoactive intestinal polypeptide 相似文献
998.
Microevolutionary dynamics of a community of Drosophilids 总被引:1,自引:1,他引:0
M. ARGEMÍ F. MESTRES A. PREVOSTI L. SERRA 《Journal of Zoological Systematics and Evolutionary Research》2003,41(1):57-63
The microevolutionary dynamics of a community of Drosophilids has been analysed in a western-Mediterranean locality (Bordils, NE of Spain) by comparing the daily and seasonal activities of the nine most abundant Drosophila species: D. subobscura , D. melanogaster , D. simulans , D. immigrans , D. phalerata , D. testacea , D. cameraria , D. hydei and D. picta collected during two periods widely distant in time. The resemblance between samples obtained in different months (seasonal component) has been determined and a clear-cut clustering of the collections according to the season is observed. A possible relationship between the environmental variables temperature and humidity, and the frequencies of the most abundant species in each seasonal cluster has been analysed by a correspondence analysis. This study allows to characterize each species according to its activity in definite intervals of temperature and humidity. Finally, daily and monthly activity patterns of the different species have been compared and found to be equivalent in the first and second periods. The results obtained allow the characterization of the species according to the environmental variables. 相似文献
999.
哺乳动物昼夜节律调节的神经基础——昼夜光感受器 总被引:1,自引:0,他引:1
哺乳动物昼夜光感受器为一组具有直接感光功能的特殊视网膜神经节细胞 ,其基本感光色素为黑视素 .昼夜光感受器具有直接、广谱和稳定感受昼夜光变化的功能特点 .昼夜光感受器的功能是通过导引作用 ,使下丘脑视交叉上核内的昼夜节律活动与外界明 暗周期变化同步 相似文献
1000.
Gastric evacuation and daily ration were studied in juvenile scalloped hammerhead sharks in Kāne'ohe Bay in order to better understand their ecology and role as apex predators in the marine environment. Three major variables known to affect the rate of gastric evacuation were manipulated: meal size, prey species, and temperature. Rates of gastric evacuation were faster than have previously been measured for sharks. The time for 80% of the meal weight (dry) to be evacuated ranged from 5.4 to 22.1 h. Daily ration was estimated using two different methods based on gastric evacuation rates and stomach content data. Estimates ranged from 2.12% to 3.54% of the body weight, which is relatively high compared to other elasmobranchs, but lower than estimates of maintenance ration for juvenile scalloped hammerheads. Data available for diet and growth of juvenile scalloped hammerhead sharks in Kāne'ohe Bay as well as data for their prey species suggest that these sharks may be surviving much of the time at consumption levels below maintenance ration. 相似文献