scholarly journals Locomotor activity in the Namaqua rock mouse (Micaelamys namaquensis): entrainment by light manipulations

2014 ◽  
Vol 92 (12) ◽  
pp. 1083-1091 ◽  
Author(s):  
I. van der Merwe ◽  
N.C. Bennett ◽  
A. Haim ◽  
M.K. Oosthuizen
Keyword(s):  
Locomotor Activity ◽  
Activity Rhythm ◽  
Light Cycle ◽  
Nocturnal Activity ◽  
Dark Cycle ◽  
Subjective Night ◽  
Activity Onset ◽  
Role Of Light ◽  
Constant Dark

The locomotor activity rhythms of wild-caught Namaqua rock mice (Micaelamys namaquensis (A. Smith, 1834)) were examined under four light-cycle regimes to quantitatively describe the daily expression of locomotor activity and to study the innate relationship between activity and the light–dark cycle. Activity was always significantly higher at night than during the day; we note four trends. (1) The LD1 light cycle (12 h light : 12 h dark) established a distinct light-entrained and strongly nocturnal activity rhythm (99.11% nocturnal activity). The activity onset was prompt (zeitgeber time (ZT) 12.2 ± 0.04) and activity continued without any prominent peaks or extended times of rest until the offset of activity at ZT 23.73 ± 0.08. (2) Evidence for the internal maintenance of locomotor activity was obtained from the constant dark cycle (DD) in which locomotor activity free ran (mean τ = 23.89 h) and 77.58% of the activity was expressed during the subjective night. (3) During re-entrainment (LD2; 12 h light : 12 h dark), a nocturnal activity rhythm was re-established (98.65% nocturnal activity). (4) The inversion of the light cycle (DL; 12 h dark : 12 h light) evoked a shift in activity that again revealed dark-induced locomotor activity (95.69% nocturnal activity). Females were consistently more active than males in all of the light cycles, but only under the DD and LD2 cycles were females significantly more active than males. Although this species is considered nocturnal from field observations, information regarding its daily expression of activity and the role of light in its entrainment is lacking. To the best of our knowledge, this study is the first to report quantitatively on the species’ daily rhythm of activity and to investigate its relationship to the light–dark cycle.

THE ROLE OF LIGHT IN THE FRUITING OF PANUS FRAGILIS

1967 ◽  
Vol 45 (11) ◽  
pp. 1939-1943 ◽  
Author(s):  
Orson K. Miller Jr.
Keyword(s):  
Temperature Cycle ◽  
Light Cycle ◽  
Fluctuating Temperature ◽  
Time Required ◽  
Role Of Light ◽  
Pink Pigment

The role of light in the fruiting of Panus fragilis was explored under controlled temperature and light cycles. No fruiting occurred in the absence of light. A daily light cycle of 1.5 h at 792 ft-c was sufficient to produce fruiting initials, but not mature sporophores. Only at the longest daily light cycle tested, 12 h at 792 ft-c, were mature sporophores produced. The time required was 22–31 days with a daily fluctuating temperature cycle of 22 °C for 12 h followed by 8 °C for 12 h. The development of a pink pigment associated with fruiting initials and young sporophores was strongest at the longer light cycles and almost absent in the short cycles.

scholarly journals Effects of Resveratrol on Daily Rhythms of Locomotor Activity and Body Temperature in Young and Aged Grey Mouse Lemurs

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Fabien Pifferi ◽  
Alexandre Dal-Pan ◽  
Solène Languille ◽  
Fabienne Aujard
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Biological Clock ◽  
The Elderly ◽  
Aged Mouse ◽  
Dark Cycle ◽  
Temperature Rhythm ◽  
Mouse Lemurs ◽  
Body Temperature Rhythm ◽  
Activity Onset

In several species, resveratrol, a polyphenolic compound, activates sirtuin proteins implicated in the regulation of energy balance and biological clock processes. To demonstrate the effect of resveratrol on clock function in an aged primate, young and aged mouse lemurs(Microcebus murinus)were studied over a 4-week dietary supplementation with resveratrol. Spontaneous locomotor activity and daily variations in body temperature were continuously recorded. Reduction in locomotor activity onset and changes in body temperature rhythm in resveratrol-supplemented aged animals suggest an improved synchronisation on the light-dark cycle. Resveratrol could be a good candidate to restore the circadian rhythms in the elderly.

Phase-resetting action of light on the circadian activity rhythm of Rattus exulans

1983 ◽  
Vol 245 (1) ◽  
pp. R10-R17
Author(s):  
P. H. Gander ◽  
R. D. Lewis
Keyword(s):  
Activity Rhythm ◽  
Phase Relationship ◽  
Masking Effect ◽  
Phase Resetting ◽  
Response Curves ◽  
Light Pulses ◽  
Subjective Night ◽  
Activity Onset ◽  
Effect Of Light

The phase resetting action of light on the circadian rhythm of locomotor activity has been examined in wild-caught Polynesian rats (Rattus exulans). Phase-response curves to 4-, 8-, and 16-h light pulses have been derived. All three curves conform to the generalization that pulses occurring during late subjective day and early subjective night produce delays, whereas advances occur in response to pulses coinciding with the late subjective night and early subjective day. Weak (type 1) phase resetting is observed in response to 4-h pulses and perhaps 8-h pulses, whereas strong (type 0) resetting apparently occurs in response to 16-h pulses. These data evidently constitute the first report of strong phase resetting in mammalian circadian rhythms. The phase relationship between an entrained activity rhythm and the light-dark cycle is dependent on the photoperiod and, in 24-h cycles, on the period difference between the rhythm and the zeitgeber. In longer zeitgeber cycles, activity onset is delayed by a direct masking effect of light. A primarily nonparametric action of light in natural entrainment is consistent with these data and with field observations.

scholarly journals Bright light during lactation alters the functioning of the circadian system of adult rats

2000 ◽  
Vol 278 (1) ◽  
pp. R201-R208 ◽  
Author(s):  
M. M. Canal-Corretger ◽  
T. Cambras ◽  
J. Vilaplana ◽  
A. Díez-Noguera
Keyword(s):  
Motor Activity ◽  
Activity Rhythm ◽  
Bright Light ◽  
Circadian System ◽  
Constant Darkness ◽  
Adult Rats ◽  
Light Pulses ◽  
Circadian Time ◽  
Role Of Light

To examine the role of light in the maturation of the circadian pacemaker, twelve groups of rats were raised in different conditions of exposure to constant bright light (LL) during lactation: both duration and timing of LL were varied. We studied the motor activity rhythm of the rats after weaning, first under LL and then under constant darkness (DD). In DD, two light pulses [at circadian time 15 (CT15) and CT22] were applied to test the response of the pacemaker. Greater exposure to LL days during lactation increased the number of rhythmic animals and the amplitude of their motor activity rhythm in the LL stage and decreased the phase delay due to the light pulse at CT15. The timing of LL during lactation affected these variables too. Because the response of the adult to light depended on both the number and timing of LL days during lactation, the exposure to light at early stages may influence the development of the circadian system by modifying it structurally or functionally.

Environmental Influence on Locomotor Activity in Nephrops Norvegicus (Crustacea: Decapoda)

1980 ◽  
Vol 60 (1) ◽  
pp. 103-113 ◽  
Author(s):  
T. H. Moller ◽  
E. Naylor
Keyword(s):  
Locomotor Activity ◽  
Light Intensity ◽  
Environmental Influence ◽  
Activity Patterns ◽  
Nephrops Norvegicus ◽  
Experimental Conditions ◽  
Emergence Patterns ◽  
Role Of Light ◽  
Trawl Catches

Diel variations in the emergence of the burrowing prawn Nephrops norvegicus (L.) have been investigated by direct field observations (Chapman & Rice, 1971; Chapman, Johnstone & Rice, 1975; Chapman & Howard, 1979; Atkinson & Naylor, 1976), and indirectly by sequential trawling during 24 h periods (Höglund & Dybern, 1965; Simpson, 1965; Hillis, 1971; Farmer, 1974; Atkinson & Naylor, 1976; Oakley, 1979). Peak emergence appears to be related to temporal and depth-dependent variations in daylight penetration, since Nephrops are apparently nocturnal in shallow waters, crepuscular as the depth increases, and diurnal at the greatest depths of their occurrence. This lends support to the suggestion that emergence occurs at an optimum light intensity (Hillis, 1971; Chapman, Priestley & Robertson, 1972; Chapman, et al., 1975; Chapman & Howard, 1979). However, additional factors influencing emergence of Nephrops from their burrows have also to be taken in account, since laboratory studies of locomotor activity in Nephrops have consistently revealed nocturnal activity patterns in light-dark (LD) regimes, with light inhibiting locomotor activity even at extremely low irradiance levels (Arechiga & Atkinson, 1975; Atkinson & Naylor, 1973, 1976; Naylor & Atkinson, 1976). Moreover, Hammond & Naylor (1977 a) have presented qualitative evidence that the nocturnal locomotor activity peak appears to be synchronized by falling light intensity at dusk. The differences between these experimental results and emergence patterns deduced from trawl catches and underwater observations of Nephrops have not been fully resolved by studies of the role of light intensity and of gradual light transitions (Arechiga & Atkinson, 1975; Hammond & Naylor, 1977 a, b). Thus the behavioural responses of Nephrops both in the field and in the laboratory need to be assessed in relation to more accurately quantified light changes. Also, despite earlier evaluation of the problem (Atkinson & Naylor, 1976; Hammond & Naylor, 1977a) it is necessary to reconsider the possibility that the patterns of locomotor activity recorded in the laboratory are influenced by experimental conditions, as has been demonstrated for minnows (Jones, 1956), and flatfish (Verheijen & de Groot, 1967).

scholarly journals Entrainability of Locomotor Activity Rhythm to the Reversed Light-dark Cycle in the Hagfish.

1993 ◽  
Vol 59 (7) ◽  
pp. 1147-1150 ◽  
Author(s):  
Hiroshi Kabasawa ◽  
Sadako Ooka-Souda ◽  
Fumio Takashima
Keyword(s):  
Locomotor Activity ◽  
Activity Rhythm ◽  
Dark Cycle ◽  
Locomotor Activity Rhythm

Sex differences in the circadian control of hamster wheel-running activity

1983 ◽  
Vol 244 (1) ◽  
pp. R93-R105 ◽  
Author(s):  
F. C. Davis ◽  
J. M. Darrow ◽  
M. Menaker
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Wheel Running ◽  
Phase Shifts ◽  
Light Cycle ◽  
Dark Cycle ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Activity Onset ◽  
Males And Females

The circadian pacemaker that underlies the wheel-running activity of hamsters was studied in males and females. Sex differences were found in the mechanism by which the pacemaker entrains to light-dark cycles and in the timing of activity onset. When exposed to a light-dark cycle with a period of 24.75 h (with 1 h of light/cycle), males show a greater ability to maintain entrainment than do females. This difference in the upper limit of entrainment appears due to a sex difference in the magnitude of light-induced phase shifts. A small difference in free-running period may also contribute to the sex difference in entrainment. Two weeks after castration of adults, the sex difference in entrainment is not affected, indicating that the difference does not depend on circulating gonadal steroids or on estrous cyclicity of the female. However, castration of females at an early age increases their ability to entrain, whereas long-term castration of males seems to reduce entrainment ability. During entrainment to a 24-h light-dark cycle (LD 14:10), females were found to begin their daily activity before males and before castrated females. This difference is consistent with a sex difference in the magnitude of light-induced phase shifts and in entrainment of the pacemaker. However, evidence is given that the sex difference in activity onset might also be caused by a sex difference in the relationship of locomotor activity to the pacemaker in intact males and females.

scholarly journals Short Neuropeptide F regulates the starvation mediated enhanced locomotor Activity in Drosophila

2019 ◽  
Author(s):  
Anna Geo ◽  
Himani Pathak ◽  
Anamika Elizabeth Kujur ◽  
Sreesha R Sudhakar ◽  
Nisha N Kannan
Keyword(s):  
Locomotor Activity ◽  
Circadian Clock ◽  
Internal Energy ◽  
Nutrient Availability ◽  
Activity Rhythm ◽  
Transcript Level ◽  
Constant Darkness ◽  
Starvation Resistance ◽  
Neuropeptide F

AbstractThe circadian clock regulates various behavioral, metabolic and physiological processes to occur at the most suitable time of the day. Internal energy stores and nutrient availability modulates the most apparent circadian clock mediated locmotor activity rhythm in Drosophila. Although previous studies unraveled the role of circadian clock in metabolism and activity rest rhythm, the precise pathway through which the circadian neuropeptidergic signaling regulates internal energy storage and the starvation-mediated increase in activity resembling foraging remains largely unclear. This study was aimed to elucidate the role of circadian neuropeptide, short neuropeptide F (sNPF) in triglyceride metabolism, starvation resistance and starvation-mediated increased locomotor activity in Drosophila. The results showed that snpf transcripts exhibits significant rhythmicity in wild type flies under 12:12 hour light-dark cycles (LD) and constant darkness (DD) whereas snpf transcript level in period null flies did not exhibit any significant rhythmicity under LD. Knockdown of sNPF in circadian clock neurons reduced the triglyceride level, starvation resistance and increased the starvation-mediated hyperactivity response after 24 hour of starvation. Further studies showed that knock down of sNPF receptors (sNPFR) expressed in insulin producing cells (IPC) increased the starvation resistance and reduced starvation-induced hyperactivity response after 24 hour of starvation. Collectively, our results suggest that transcriptional oscillation of snpf mRNA is endogenously controlled by the circadian clock and elucidate the role of sNPF in modulating locomotor activity in accordance with the nutrient availability in Drosophila.

Daily hypothermia and torpor in a tropical primate: synchronization by 24-h light-dark cycle

2001 ◽  
Vol 281 (6) ◽  
pp. R1925-R1933 ◽  
Author(s):  
M. Perret ◽  
F. Aujard
Keyword(s):  
Locomotor Activity ◽  
Fixed Time ◽  
Temporal Organization ◽  
Physiological Changes ◽  
Dark Cycle ◽  
Subjective Night ◽  
Free Running ◽  
Rapid Drop ◽  
Gray Mouse Lemur ◽  
Short Days

To study the temporal organization of daily hypothermia and torpor in a nocturnal Malagasy primate, the gray mouse lemur, body temperature (Tb) and locomotor activity were recorded using telemetry on 39 males held in 24-h light-dark cycles of different photoperiods. Under free-running condition, the circadian Tb and locomotor activity rhythms had a period shorter than 24 h. Circadian daily hypothermia started by a rapid drop in Tb (0.24°C/10 min) at the end of subjective night (13 h 25 ± 20 min) and was characterized by minimal Tb values 3 h 20 ± 5 min later. Spontaneous arousal from daily hypothermia occurred at a fixed time (6 h 05 ± 15 min, n = 7) after the beginning of subjective day. In animals exposed to 24-h light-dark cycles with night duration varying from 10 to 14 h, locomotor activity was strictly restricted to dark time, but the temporal organization of daily hypothermia was not modified, although changes in amplitude of Tb rhythm were observed. Daily hypothermia was directly induced by light and lasted 5 h 10 ± 10 min, with minimal Tb values 3 h 30 ± 30 min ( n = 28) after lights on, on condition that nighttime did not exceed the duration of subjective night. However, in animals exposed to 24-h light-dark cycles with night duration varying from 10 to 5 h, the limit of induction of daily hypothermia by light was ∼9 h after the beginning of night. Finally, under short days (14:10-h light-dark cycle), long bouts (6 h 50 ± 40 min) of actual torpor (minimum Tb 27.6 ± 0.9°C) were observed and would involve mechanisms depending on physiological changes induced by short day exposure.

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