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.

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.

scholarly journals The neuropeptide F/nitric oxide pathway is essential for shaping locomotor plasticity underlying locust phase transition

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Li Hou ◽  
Pengcheng Yang ◽  
Feng Jiang ◽  
Qing Liu ◽  
Xianhui Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Locomotor Activity ◽  
Molecular Mechanisms ◽  
Behavioral Plasticity ◽  
Critical Role ◽  
Transcript Level ◽  
Neuropeptide F ◽  
Oxide Synthase ◽  
Nitric Oxide Pathway ◽  
Downstream Mediator

Behavioral plasticity is widespread in swarming animals, but little is known about its underlying neural and molecular mechanisms. Here, we report that a neuropeptide F (NPF)/nitric oxide (NO) pathway plays a critical role in the locomotor plasticity of swarming migratory locusts. The transcripts encoding two related neuropeptides, NPF1a and NPF2, show reduced levels during crowding, and the transcript levels of NPF1a and NPF2 receptors significantly increase during locust isolation. Both NPF1a and NPF2 have suppressive effects on phase-related locomotor activity. A key downstream mediator for both NPFs is nitric oxide synthase (NOS), which regulates phase-related locomotor activity by controlling NO synthesis in the locust brain. Mechanistically, NPF1a and NPF2 modify NOS activity by separately suppressing its phosphorylation and by lowering its transcript level, effects that are mediated by their respective receptors. Our results uncover a hierarchical neurochemical mechanism underlying behavioral plasticity in the swarming locust and provide insights into the NPF/NO axis.

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.

scholarly journals Role of mutation of the circadian clock gene Per2 in cardiovascular circadian rhythms

2010 ◽  
Vol 298 (3) ◽  
pp. R627-R634 ◽  
Author(s):  
Ana Vukolic ◽  
Vladan Antic ◽  
Bruce N. Van Vliet ◽  
Zhihong Yang ◽  
Urs Albrecht ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Circadian Clock ◽  
Mutant Mice ◽  
Constant Darkness ◽  
Wild Type ◽  
Chi Square ◽  
Dark Light

Alterations in the circadian blood pressure pattern are frequently observed in hypertension and lead to increased cardiovascular morbidity. However, there are no studies that have investigated a possible implication of the Period2 gene, a key component of the molecular circadian clock, on the circadian rhythms of blood pressure and heart rate. To address this question, we monitored blood pressure, heart rate, and locomotor activity 24 h a day by telemetry in mice carrying a mutation in the Period2 gene and in wild-type control mice. Under a standard 12:12-h light-dark cycle, mutant mice showed a mild cardiovascular phenotype with an elevated 24-h heart rate, a decreased 24-h diastolic blood pressure, and an attenuation of the dark-light difference in blood pressure and heart rate. Locomotor activity was similar in both groups and did not appear to explain the observed hemodynamic differences. When mice were placed under constant darkness during eight consecutive days, wild-type mice maintained 24-h rhythms, whereas there was an apparent progressive loss of 24-h rhythm of blood pressure, heart rate, and locomotor activity in mutant mice. However, a chi square periodogram revealed that circadian rhythms were preserved under complete absence of any light cue, but with shorter periods by ∼40 min, leading to a cumulative phase shift toward earlier times of ∼5 h and 20 min by the end of the 8th day. When heart rate, mean arterial pressure, and activity were recalculated according to the endogenous circadian periods of each individual mouse, the amplitudes of the circadian rhythms (“subjective night”-“subjective day” differences) were maintained for all variables studied. Our data show that mutation of the Period2 gene results in an attenuated dipping of blood pressure and heart rate during both light-dark cycles and constant darkness, and in shorter circadian periods during constant darkness.

scholarly journals Shedding Light on the Circadian Clock of the Threespine Stickleback

2021 ◽  
Author(s):  
Marie-Pier Brochu ◽  
Nadia Aubin-Horth
Keyword(s):  
Circadian Clock ◽  
Gasterosteus Aculeatus ◽  
Clock Genes ◽  
Activity Rhythm ◽  
Internal Clock ◽  
Interindividual Variation ◽  
Masking Effect ◽  
Constant Darkness ◽  
Natural Environments ◽  
Threespine Sticklebacks

The circadian clock is an internal timekeeping system shared by most organisms, and knowledge about its functional importance and evolution in natural environments is still needed. Here, we investigated the circadian clock of wild-caught threespine sticklebacks (Gasterosteus aculeatus) at the behavioural and molecular levels. While their behaviour, ecology, and evolution are well studied, information on their circadian rhythms are scarce. We quantified the daily locomotor activity rhythm under a light-dark cycle (LD) and under constant darkness (DD). Under LD, all fish exhibited significant daily rhythmicity, while under DD, only 18% of individuals remained rhythmic. This interindividual variation suggests that the circadian clock controls activity only in certain individuals. Moreover, under LD, some fish were almost exclusively nocturnal, while others were active around the clock. Furthermore, the most nocturnal fish were also the least active. These results suggest that light masks activity (i.e. suppresses activity without entraining the internal clock) more strongly in some individuals than others. Finally, we quantified the expression of five clock genes in the brain of sticklebacks under DD using qPCR. We did not detect circadian rhythmicity, which could either indicate that the clock molecular oscillator is highly light-dependent, or that there was an oscillation but that we were unable to detect it. Overall, our study suggests that a strong circadian control on behavioural rhythms may not necessarily be advantageous in a natural population of sticklebacks and that the daily phase of activity varies greatly between individuals because of a differential masking effect of light.

scholarly journals Shedding Light on the Threespine Stickleback Circadian Clock

2021 ◽  
Author(s):  
Marie-Pier Brochu ◽  
Nadia Aubin-Horth
Keyword(s):  
Circadian Clock ◽  
Gasterosteus Aculeatus ◽  
Clock Genes ◽  
Activity Rhythm ◽  
Interindividual Variation ◽  
Masking Effect ◽  
Constant Darkness ◽  
Natural Environments ◽  
Threespine Sticklebacks ◽  
Nocturnal Fish

The circadian clock is an internal timekeeping system shared by most organisms, and knowledge about its functional importance and evolution in natural environments is still needed. Here, we investigated the circadian clock of wild-caught threespine sticklebacks (Gasterosteus aculeatus) at the behavioural and molecular levels. While their behaviour, ecology, and evolution are well studied, information on their circadian rhythms are scarce. We quantified the daily locomotor activity rhythm under a light-dark cycle (LD) and under constant darkness (DD). Under LD, all fish exhibited significant daily rhythmicity, while under DD, only 18% of individuals remained rhythmic. This interindividual variation suggests that the circadian clock controls activity only in certain individuals. Moreover, under LD, some fish were almost exclusively nocturnal, while others were active around the clock. Furthermore, the most nocturnal fish were also the least active. These results suggest that light masks activity more strongly in some individuals than others. Finally, we quantified the expression of five clock genes in the brain of sticklebacks under DD using qPCR. We did not detect circadian rhythmicity, which could either indicate that the clock molecular oscillator is highly light-dependent, or that there was an oscillation but that we were unable to detect it. Overall, our study suggests that a strong circadian control on behavioural rhythms may not necessarily be advantageous in a natural population of sticklebacks and that the daily phase of activity varies greatly between individuals because of a differential masking effect of light.

scholarly journals Circatidal activity rhythm in the mangrove cricket Apteronemobius asahinai

2008 ◽  
Vol 4 (3) ◽  
pp. 233-236 ◽  
Author(s):  
Aya Satoh ◽  
Eiji Yoshioka ◽  
Hideharu Numata
Keyword(s):  
Locomotor Activity ◽  
Activity Rhythm ◽  
High Tide ◽  
Active Phase ◽  
Endogenous Rhythm ◽  
Constant Darkness ◽  
Mangrove Forests ◽  
Dark Cycle ◽  
Forest Floors ◽  
Free Running Period

Mangrove forests are influenced by tidal flooding and ebbing for a period of approximately 12.4 hours (tidal cycle). Mangrove crickets ( Apteronemobius asahinai ) forage on mangrove forest floors only during low tide. Under constant darkness, most crickets showed a clear bimodal daily pattern in their locomotor activity for at least 24 days; the active phases of approximately 10 hours alternated with inactive phases of approximately 2 hours, which coincided with the time of high tide in the field. The free-running period was 12.56±0.13 hours (mean±s.d., n =11). This endogenous rhythm was not entrained by the subsequent 24 hours light–dark cycle, although it was suppressed in the photophase; the active phase in the scotophase continued from the active phase in the previous constant darkness, with no phase shift. The endogenous rhythm was assumed to be a circatidal rhythm. On the other hand, the activity under constant darkness subsequent to a light–dark cycle was more intense in the active phase continuing from the scotophase than from the photophase of the preceding light–dark cycle; this indicates the presence of circadian components. These results suggest that two clock systems are involved in controlling locomotor activity in mangrove crickets.

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