Circadian Rhythms Of Locomotion Research Articles

Circadian rhythms of locomotor activity in Indian walking catfish, Clarias batrachus

The circadian rhythm of locomotor activity was assayed in both sexes of Clarias batrachus using infrared sensors connected to an Angus event recorder. Circadian parameters of locomotor activity rhythm, such as rhythm-adjusted average (Mesor), amplitude (A), acrophase (Ø) and period (τ), were determined in C. batrachus maintained under LD 12:12 (I), DD, LD 12:12 (II) and LL for given number of days in each schedule. Each individual fish was exposed to different LD schedules in the order mentioned above. Results of this study revealed that (1) C. batrachus is nocturnal; (2) it exhibits LD-entrainment of its locomotor activity that free-runs under constant conditions; and (3) the period of its locomotor activity rhythm is independent of the factor gender. It appears that multiple oscillators underlie the overt circadian rhythm of locomotion in C. batrachus. This catfish is an important commercial species and understanding of its circadian clock might help in the optimization of its management and pisciculture practices.

Development of the circadian clock in the German cockroach, Blattella germanica

The cell distribution and immunoreactivity (ir) against period (PER), pigment dispersing factor (PDF) and corazonin (CRZ), were compared between adults and nymphs in the central nervous system of the German cockroach. Although PER-ir cells in the optic lobes (OL) were expressed in the nymphs from the first instar, the links between major clock cells became more elaborated after second/third instar. A circadian rhythm of locomotion was initiated at the fourth/fifth instar. The results suggest that the clock was running from hatching, but the control network needed more time to develop. In addition, the putative downstream regulators, PDF-ir and CRZ-ir, are co-localized in various regions of the brain, indicating potential output routes of the circadian clock. CRZ-ir cells with typical morphology of neurosecretory cells in the dorsolateral protocerebrum send out three neural fibers to reach the ipsilateral corpora cardiaca (CC), the antennal lobe and two hemispheres of the protocerebrum. Based on co-localization with some PER-ir/PDF-ir cells, the CRZ-ir cells have the potential to serve as a bridge between circadian neural signals and endocrine regulation. Based on PDF's role in the regulation of locomotion, our results support the finding that the locomotor circadian rhythm is possibly controlled by a hormonal route.

Circadian rhythms of heart rate in freely moving and restrained American lobsters, Homarus americanus

While circadian rhythms of locomotion have been reported in the American lobster, Homarus americanus, it is unclear whether heart rate is also modulated on a circadian basis. To address this issue, both heart rate and locomotor activity were continuously monitored in light-dark (LD) cycles and constant darkness (DD). Lobsters in running wheels exhibited significant nocturnal increases in locomotor activity and heart rates during LD, and these measures were significantly correlated. In DD, most lobsters exhibited persistent circadian rhythms of both locomotion and heart rate. When heart rate was monitored in restrained lobsters in LD and DD, most animals also demonstrated clear daily and circadian rhythms in heart rate. Overall, this is the first demonstration of circadian rhythms of heart rate in H. americanus, the expression of which does not appear to be dependent on the expression of locomotor activity.

Time collides with reproduction – reproductive cycles masking the circadian rhythm of locomotion in the German cockroach

Time collides with reproduction – reproductive cycles masking the circadian rhythm of locomotion in the German cockroach

Locomotor Activity of the Fiddler Crab, Uca subcylindrica (Stimpson), under Artificial Illumination

Specimens of the fiddler crab Uca subcylindrica (Stimpson) were captured in south Texas (USA) for locomotor rhythm studies. Actographic data were analyzed using Tau™ sofware. Under constant illumination (LL) and darkness (DD), the semiterrestrial crabs express a circadian rhythm of locomotion. When exposed to illumination/darkness cycles (LD12:12 or LD14:10), their bouts of activity are entrained to the photoperiod. In LD, activity is generally bimodal with an initial burst about 0.5 h after illumination. A second burst of activity begins 1 to 2 h before the end of illumination. When transferred from LD to LL, a locomotor rhythm with an average period of 24.6 ± 1.0 h (n = 19) is expressed in 89 percent of the crabs. On the other hand, when placed in DD after LD (n = 8), the crabs are either arrythmic or weakly rhythmic (period = 23.8 ± 0.2 h; n = 2). If the onset of illumination is advanced by 6 h, a period of less than 24.0 h is detected in the actogram. If the onset of illumination is delayed by 6 h, a locomotor rhythm with a period greater than 24.0 h appears. The locomotor behavior of this species of fiddler crab, Uca subcylindrica, is not related to the tidal rhythmicities seen in other members of the genus Uca. Rather, it has strong circadian components.

Food as a circadian Zeitgeber for house sparrows: the effect of different food access durations.

House sparrows (Passer domesticus) can synchronize their circadian rhythms of locomotion and feeding with times of periodic food availability. In contrast to most mammals, which synchronize only a specific part of their circadian system with feeding cycles and thus express two distinct activity components, house sparrows synchronize their circadian activity rhythms as a whole with the food zeitgeber. Previous results had indicated that feeding cycles act as comparatively weak zeitgebers for house sparrows. In the present study, therefore, we investigate whether feeding schedules are weak zeitgebers in general or whether their impact on the circadian system of the birds depends on the degree of food restriction. A detailed analysis of the synchronization pattern under the different experimental conditions should help to clarify whether house sparrows use a different mechanism for food-synchronization than mammals. House sparrows were kept in continuous dim light and exposed to different feeding schedules with daily food access durations ranging from 8 to 20 h. Many birds lost synchronization and exhibited free-running rhythms in locomotor and feeding activity when the daily food access duration was lengthened but became synchronized when the feeding duration was shortened. The interpretation that short food access durations represent stronger zeitgebers than long food access durations was supported by the occurrence of large negative phase-angle differences during long daily feeding schedules, contrasting with small and sometimes positive phase-angle differences under short food access durations. There were no indications that house sparrows possess a specific food-entrainable circadian oscillator as mammals do. Rather, periodic food availability seems to be a zeitgeber for the whole circadian system, which, hence, can be synchronized both by light and food. An explanation for such different mechanisms of food-synchronization is offered in the feeding ecology of these animals. Birds may evaluate the importance of a specific feeding schedule as a zeitgeber either from temporal information on the duration of the daily food access time or from energetic considerations. The phase-angle differences associated with the different feeding schedules and the maintenance of daily activity times may ensure an appropriate temporal integration of behavior with specific conditions. Non-synchronized birds exhibited masking-induced feeding activity, which might represent an alternative means of adjusting to feeding cycles when synchronization cannot occur.

Mosaic analysis in the Drosophila CNS of circadian and courtship-song rhythms affected by a period clock mutation.

The period gene in Drosophila melanogaster controls not only daily rhythms associated with adult emergence and behavior, but also a much higher frequency rhythm that accompanies the male's courtship song. This oscillation in the rate of sound production (normal period, ca. one minute) is either sped up (by perS), slowed down, or eliminated in the three classic per mutants. We have conducted a mosaic analysis in which both lovesong and circadian locomotor cycles were examined in a series of flies that were each part perS and part per+. Consistent with previous studies, the focus for per control of the adult's circadian rhythm of locomotion was found to be in the brain. However, several mosaic individuals were found to exhibit a mutant locomotor rhythm but a wild-type song cycle, or vice-versa, enabling us provisionally to map the song-rhythm focus to the thoracic ganglia. That per is expressed only in glial cells in the thoracic nervous system and, in general, mediates slow (hour-by-hour) fluctuations in the levels of its own products are discussed from the standpoint of the current mosaic mapping results and the renewed focus they bring to the gene's influence on an ultradian rhythm.

Circadian timekeeping in BALB/c and C57BL/6 inbred mouse strains

Circadian rhythms of locomotion (wheel-running activity) in 12 inbred mouse strains were recorded for interstrain differences in tau DD, the endogenous (free-running) period of the circadian pacemaker measured in constant environmental darkness. The results indicate that 1 or more genetic loci influence the value of tau DD, and a large (50 min) difference in mean tau DD between 2 of the strains, BALB/cByJ and C57BL/6J, allowed further characterization of the origins and inheritance of the polymorphic expression of this circadian pacemaker property. The interstrain difference in mean tau DD was associated with an interstrain difference in light-induced shifts of the phase of the free-running locomotor rhythm; the BALB/c strain (with the shorter mean tau DD) displayed relatively fewer advance phase shifts. Neither the history of previous light exposure, albinism, nor elevated circulating testosterone levels could account for the interstrain difference in mean tau DD. The value of tau DD based on the circadian rhythm of drinking activity (with the running wheel removed) was longer than that based on locomotion; this discrepancy was significantly greater and more variable in BALB/c than in C57BL/6 mice, though the interstrain difference in mean tau DD could not be attributed entirely to this effect. Reciprocal F1 hybrids of BALB/c x C57BL/6 matings revealed dominance of the C57BL/6 genotype, no sex linkage, and a significant (but small) maternal effect. Examination of CXB recombinant inbred strains provided no support for the hypothesis of monogenic inheritance. Further study of inherited differences in the BALB/c and C57BL/6 strains may be a useful noninvasive experimental approach for investigation of the neurobiological substrates of circadian rhythmicity.

Circadian rhythm of cat flea (Siphonaptera: Pulicidae) locomotion unaffected by ultrasound.

Cat fleas, Ctenocephalides felis (Bouché), had a circadian rhythm of locomotion that peaked during the last 2 h of the photophase and declined to a lower level that was maintained throughout the scotophase. Activity was lowest during the first 8 h of photophase. The circadian rhythm of these fleas was not affected by an ultrasonic pest control device.

Therapeutic effects of delta-sleep-inducing peptide (DSIP) in patients with chronic, pronounced pain episodes. A clinical pilot study.

Experimental results suggested a modulation or 'programming' interaction of delta sleep-inducing peptide (DSIP) with endogenous opioid-peptidergic systems and exogenous intracerebrally or systemically administered morphine and amphetamine. The induction of cerebral MAO-A activity, a pronounced influence on the circadian rhythms of locomotion and intracerebral neurotransmitter as well as plasma protein and cortisol concentrations has been reported. DSIP was also shown to counteract experimentally induced stress situations in animals. An improvement of the psychomotor performance and the concentration capacity in humans beside sleep normalization and pronounced effects on withdrawal symptoms including pain states in alcoholics and opiate addicts was discovered. This encouraged a pilot study for a possible action of the peptide in humans suffering from chronic pronounced pain episodes. We investigated the therapeutic effect in 7 patients with migraine episodes and vasomotor headaches, chronic tinnitus and psychogenic pain attacks. The anamnestic (baseline) values were statistically compared with the katamnestic control period. DSIP lowered significantly the pain levels of 6 out of 7 patients after intravenous administration on 5 consecutive days followed by 5 injections every 48-72 h. Remarkably, a simultaneous significant reduction of the concomitantly occurring depressive states was observed.

Circadian Rhythms of Locomotion in Six Noctuid Species1

An actograph system was developed and used to record hourly locomotor activity for adult cabbage loopers, Trichoplusia ni (Hübner), soybean loopers,Pseudoplusia includens (Walker), velvetbean caterpillars, Anticarsia gemmatalis (Hübner), beet armyworms, Spodoptera exigua (Hübner), fall armyworms, S. frugiperda (J. E. Smith), and corn earworms, Heliothis zea (Boddie). The peak nocturnal activity of velvetbean caterpillars and corn earworms was greater than that of the other moths; and, except for these 2 species, males moved more often than females. Pairs were considerably less active and lived for fewer days than the isolated sexes.

Circadian Rhythms of Locomotion in Adult Caribbean Fruit Flies

Circadian Rhythms of Locomotion in Adult Caribbean Fruit Flies

Circadian rhythm of locomotion and its temperature dependence in Blattella germanica.

ABSTRACT The activity in Blattella germanica was investigated under standard conditions. Periods of latency and increment were recognized. The free-running rhythm in continuous darkness was determined at different temperatures and showed about the same period. The free-running rhythm in confinons light could not be determined unless the light intensity was extremely low. The period of activity was not released immediately after a change from light to darkness if this was advanced in relation to the normal time. The activity was then only slightly advanced. Delay of the onset of darkness caused the activity to diminish gradually after the usual time of change from light to dark. If the temperature was lowered some time before the expected time of activity in continuous darkness the activity was advanced much more than normally. If the temperature was raised the activity was delayed. Based upon these and other studies, a theory is advanced which explains the activity rhythms in insects as being the result of the interaction between a gradually increasing, temperature-dependent sensitization and different thresholds of release determined by light and temperature. A theory is propounded concerning the temperature-independence of the free-running rhythm in continuous darkness, assuming a temperature-dependent threshold of release.