Diurnal Rhythms Of Locomotor Activity Research Articles

Effects of Dietary and Lighting Conditions on Diurnal Locomotor Activity and Body Temperature in Microminipigs.

The effects of dietary and lighting conditions on diurnal rhythm of locomotor activity (LA) and body temperature (BT) using four adult male microminipigs were investigated. Different feeding times, diet and lighting conditions were applied sequentially for 3 weeks in each phase as follows: Phase I: Morning mealtime, normal diet, 12-h lights on; phase II: mealtime changed to afternoon; phase III: diet changed to high-fat diet; phase IV: lighting changed to 20-h on; and phase V: phase I repeated. LA was measured by an actigraph which was worn on the body of each pig. A BT recording module (Thermochron Type-SL) was implanted in the neck subcutaneously. Phase II increased BT compared with phase I. Phase III increased LA and BT compared with phase II. Phase IV increased LA compared with phase III. LA in phase V was higher compared with phase I. These results can be extrapolated to other diurnal animals such as humans. This study provides an example of the effects of diet and lighting on biological activities in microminipigs under low-invasive procedures measuring LA and BT, leading to low variations in these measures.

150. Disruption of the gut microbiome with oral antibiotic reduces core body temperature and disrupts diurnal rhythms of locomotor activity, but not sleep, in rats

The bidirectional communication between the gut microbiota and the brain (i.e. the gut-brain axis) can modulate behavior and neurochemical systems. Recent evidence suggests that the absence of gut microbiota can affect clock genes in peripheral tissues that could influence diurnal rhythms; and serotonin in the brain that can modulate sleep/wake behavior and temperature regulation. Thus, we hypothesized that depletion of the gut microbiota, using oral antibiotics, may disrupt diurnal rhythms, thermoregulation and sleep. Using in vivo biotelemetry, we recorded diurnal rhythms of locomotor activity (LA), core body temperature (CBT), and sleep (%REM, %NREM, %WAKE) in freely moving adult male F344 rats. Rats were given oral antibiotics (4.0 mg/ml streptomycin and 2.0 mg/ml penicillin g) in their drinking water. Total aerobic, anaerobic, Lactobacillus spp. and Bifidobacterium spp. per g of feces was determined using selective culture. After seven days of antibiotic treatment, animals had depleted gut microbiota, reduced overall CBT, and a flattened diurnal rhythm of LA when compared to baseline, while sleep architecture remained unchanged. Interestingly, five days after cessation of antibiotic, only Lactobacillus spp. remained depleted. Reduced CBT and flattened diurnal rhythm of LA also persisted. These results support a link between the gut microbiota, temperature regulation and diurnal physiology. Furthermore, they suggest that disruptions to the gut microbiota, and any resultant physiological consequences, may be long lasting even if antibiotic administration is transient.

Effect of photoperiod stress assessment and locomotor activity of female lambari (Astyanax bimaculatu)

Some studies and scientific investments have been done in aquaculture aiming to minimize the stress of the fish due to different factors, as management, nutritional status, water quality, temperature, photoperiod, and salinity. This study aimed to verify the effect of photoperiod on locomotor activity and plasma levels of cortisol and glucose in female Lambari. One hundred and twenty female Lambari adult were maintained in aquaria of 20 liters each in a completely randomized design with three treatments (T1 = 0Light: 24Dark, T2 = 12L: 12D, T3 = 24L: 0D) and four replications. The daily locomotor activity was registered during 15 days using an infrared photocell. After 40 days of experiment and previous fasting for 24 hours, fish were euthanized by a lethal dose of benzocaine. Female Lambari featured a diurnal rhythm of locomotor activity. Lambari subjected to 12:12 and LD photoperiod presented higher cortisol (12L:12E: 190.00 ± 37.73 ng/mL e 24L:0E: 148.850 ± 32.77 ng/mL) and locomotor activity levels and also lower survival rates (30.0 ± 7.07%) when compared to the LD photoperiod (cortisol: 85.570 ± 7.99 ng/mL, survival rates: 72.5 ± 4.330%). The glucose concentration (32.167 ± 22.73 mg/dL) and the growth (7.050 ±0.59cm) of fish subjected to LD photoperiod was significantly lower than in the other treatments. We conclude that light plays an important role in the growth, behavior and welfare of female Lambari. Besides, our data highlighted that fish submitted to a long light period present a more stressed and more aggressive status when compared to fish submitted to a continuous darkness.

Repeated fear‐induced diurnal rhythm disruptions predict PTSD‐like sensitized physiological acute stress responses in F344 rats

To identify objective factors that can predict future sensitized stress responses, thus allowing for effective intervention prior to developing sensitization and subsequent stress-related disorders, including post-traumatic stress disorder (PTSD). Adult male F344 rats implanted with biotelemetry devices were exposed to repeated conditioned fear or control conditions for 22 days followed by exposure to either no, mild or severe acute stress on day 23. Diurnal rhythms of locomotor activity (LA), heart rate (HR) and core body temperature (CBT) were biotelemetrically monitored throughout the study. In a subset of rat not implanted, corticosterone and indices of chronic stress were measured immediately following stress. Rats exposed to repeated fear had fear-evoked increases in behavioural freezing and HR/CBT during exposure to the fear environment and displayed indices of chronic stress. Repeated fear produced flattening of diurnal rhythms in LA, HR and CBT. Repeated fear did not sensitize the corticosterone response to acute stress, but produced sensitized HR/CBT responses following acute stress, relative to the effect of acute stress in the absence of a history of repeated fear. Greater diurnal rhythm disruptions during repeated fear predicted sensitized acute stress-induced physiological responses. Rats exposed to repeated fear also displayed flattened diurnal LA and basal increases in HR. Exposure to repeated fear produces outcomes consistent with those observed in PTSD. The results suggest that diurnal rhythm disruptions during chronic stressors may help predict sensitized physiological stress responses following traumatic events. Monitoring diurnal disruptions during repeated stress may thus help predict susceptibility to PTSD.

Diurnal rhythms of locomotor activity, changes in body mass and fat reserves, standard metabolic rate, and respiratory quotient in the free-living coal tit (Parus ater) in the autumn-winter period

These studies were conducted in 1999–2010 on the territory of the Zvenigorod Biological Station of Moscow State University (western Moscow suburbs, 55°44′ N, 36°51′ E). Birds (Parus ater) were caught by mist-nets. All the birds were banded and weighed, and their fat reserves were determined; then, the birds were released. A total of 85 individuals were caught. The standard metabolic rate and respiratory quotient (by the method of indirect calorimetry) were measured in 46 experiments with 16 birds. Two peaks were distinguished in the daily locomotor activity: a strongly pronounced daily peak (from 6 a.m. to 4 p.m.) and a weak evening peak (from 6 to 10 p.m.). The body mass did not change during the day. However, some trend for an increase in the mean body mass toward the middle and end of the day was noted. The fat reserves drastically changed during the day. The metabolic rate and respiratory quotient had a well-pronounced diurnal rhythm with minimal values at night (from 12 p.m. to 4 a.m.) and maximum values in the afternoon (from 12 a.m. to 4 p.m.). The total energy budget of Parus ater in the autumn-winter period, energy balance, and the maintenance of constant flying weight along with the dynamics of fat reserves are discussed.

Effects of stressor controllability on diurnal physiological rhythms

Disruptions in circadian and diurnal rhythms are associated with stress-related psychiatric disorders and stressor exposure can disrupt these rhythms. The controllability of the stressor can modulate various behavioral and neurochemical responses to stress. Uncontrollable, but not controllable, stress produces behaviors in rats that resemble symptoms of anxiety and depression. Whether acute stress-induced disruptions in physiological rhythms are sensitive to controllability of the stressor, however, remains unknown. To examine the role of controllability in diurnal rhythm disruption, adult male Sprague–Dawley rats were implanted with Data Sciences International (DSI) biotelemetry devices. Real-time measurements were obtained before, during and after exposure to a controllable or yoked uncontrollable stressor. Controllable and uncontrollable stress equally disrupted diurnal rhythms of locomotor activity and body temperature but not heart rate. The diurnal heart rate the day following stressor exposure was flattened to a greater extent and was significantly higher in rats with control over stress suggesting a relationship between stressor controllability and the heart rate response. Our results are consistent with the conclusion that acute stress-induced disruptions in diurnal physiological rhythms likely contribute little to the behavioral and affective consequences of stress that are sensitive to stressor controllability.

Discovery of a novel avian neurosteroid, 7α-hydroxypregnenolone, and its role in the regulation of the diurnal rhythm of locomotor activity in Japanese quail

The discovery of two novel avian neurosteroids in the quail brain, 7α- and 7β-hydroxypregnenolone is described. Intracerebroventricular administration of 7α-hydroxypregnenolone, but not 7β-hydroxypregnenolone was found to stimulate locomotor activity of male quail when spontaneous nocturnal activity is low. Diurnal changes in locomotor activity in male quail were found to be correlated with a diurnal change in the concentration of diencephalic 7α-hydroxypregnenolone. This correlation was a not seen in female quail which have a lower amplitude diurnal rhythm of locomotor activity and lower daytime concentrations of diencephalic 7α-hydroxypregnenolone. Treatment of male quail with melatonin was found to depress the synthesis of 7α-hydroxypregnenolone in the diencephalon. This is a previously undescribed role for melatonin in the regulation of neurosteroid synthesis in the brain of any vertebrate. We therefore deduced in male quail, that the nocturnal depression in locomotory activity is a consequence of a depression in diencephalic 7α-hydroxypregnenolone resulting from the inhibitory action of the nocturnal increase in melatonin. This observation may be of widespread significance for the molecular control of rhythmic locomotor activity in all vertebrates.

Regulation of Hypocretin (Orexin) Expression in Embryonic Zebrafish

Hypocretins/orexins are neuropeptides involved in the regulation of sleep and energy balance in mammals. Conservation of gene sequence, hypothalamic localization of cell bodies, and projection patterns in adult zebrafish suggest that the architecture and function of the hypocretin system are conserved in fish. We report on the complete genomic structure of the zebrafish and Tetraodon hypocretin genes and the complete predicted hypocretin protein sequences from five teleosts. Using whole mount in situ hybridization, we have traced the development of hypocretin cells in zebrafish from onset of expression at 22 h post-fertilization through the first week of development. Promoter elements of similar size from zebrafish and Tetraodon were capable of driving efficient and specific expression of enhanced green fluorescent protein in developing zebrafish embryos, thus defining a minimal promoter region able to accurately mimic the native hypocretin pattern. This enhanced green fluorescent protein expression also revealed a complex pattern of projections within the hypothalamus, to the midbrain, and to the spinal cord. To further analyze the promoter, a series of deletion and substitution constructs were injected into embryos, and resulting promoter activity was monitored in the first week of development. A critical region of 250 base pairs was identified containing a core 13-base pair element essential for hypocretin expression.

1504 Diurnal rhythm of locomotor activity, body temperature, food and water intake in the af64a-induced dementia model rats

1504 Diurnal rhythm of locomotor activity, body temperature, food and water intake in the af64a-induced dementia model rats

Diurnal rhythms in locomotor activity of the house musk shrew, Suncus murinus

A diurnal rhythm of locomotor activity in male and female house musk shrews (Jic:SUN) aged approximately one year was observed under a schedule of 12 hr light and 12 hr darkness (light on at 07:00) over a period of 10 days. In general, the pattern of locomotor activity was similar in both sexes, with around 24-hr diurnal rhythm. A few typical patterns of locomotor activity in these animals were as follows: A. Locomotion interval was close in the light phase, while was sparse in the dark phase. B. As opposed to the pattern of A, locomotion interval was close in the dark and sparse in the light phases. C. Its interval remains stationary through a whole day.

Level of glucocorticoid hormones in early postnatal ontogenesis and circadian rhythms of endocrine-metabolic functions in adult rats.

The disturbance of the glucocorticoid balance in early postnatal ontogenesis (17-19 days) as the result of prednisolone administration has been shown to lead to partial suppression of circadian adrenocortical activity in adult rats. The circadian rhythm of FFA in these groups of animals was not detectable and the circadian acrophase of blood glucose concentration changed, while diurnal urine periodicity remained unchanged. The diurnal rhythm of locomotor activity in prednisolone-pretreated rats was characterized by a later onset of increase in its activity and a shorter duration.

The behaviour of Bulinus africanus: A circadian profile

Six different behaviour patterns have been studied across the circadian spectrum in the tropical freshwater snail Bulinus africanus. Snails entrained to a circadian light/dark regimen show a diurnal rhythm of locomotor activity, and feeding, photokinetic responsiveness, egg laying and hatching all follow a similar pattern. The rhythms are endogenous and persist under constant conditions. In contrast defaecation occurs mainly during the dark period. This antiphase relationship may be due in part to a cycle of absorption and fragmentation in the digestive gland cells, but it is likely that other factors are involved.

Correlation between neurosecretion and some physiological functions of the scorpionHeterometrus swammerdami

The diverse types of neurosecretory cells located in the brain and suboesophageal ganglion of the scorpionHeterometrus have shown morphological evidence of activity in relation to diverse physiological functions. Some of the functions investigated were the process of delivery of the young, apolysis, ecdysis, growth, maturation, water relations, diurnal rhythms of locomotor activity and temperature adaptation. Continuous light and continuous darkness reflected change in the activity of specific groups of neurosecretory cells. In this Arachnid also, neurosecretion seems to play a central role in the regulation of many physiological activities as in insects and other organisms.

A DIURNAL ACTIVITY RHYTHM IN PLETHODON CINEREUS AND ITS MODIFICATION BY AN INFLUENCE HAVING A LUNAR FREQUENCY

1. The salamander, Plethodon cinereus, shows a diurnal rhythm of locomotor activity, both in alternating 12-hour periods of light and darkness, and in continuous darkness.2. The diurnal rhythm is strongly modified by a depressive influence that is apparently associated with the time of lunar zenith.3. The activity of the animal at any given time is a function of the diurnal and lunar influences operative at that time.4. The significance of the rhythm to the animal in nature is discussed.