Locomotor activity responses in juvenile sockeye salmon, Oncorhynchus nerka, to melatonin and serotonin

1970 ◽  
Vol 48 (6) ◽  
pp. 1425-1427 ◽  
Author(s):  
John E. Byrne
Keyword(s):  
Locomotor Activity ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Dark Phase ◽  
Light Phase ◽  
Selective Activity

Intraperitoneal injections administered for 3 consecutive days to juvenile sockeye salmon resulted in selective activity responses to either the light or the dark phase of the photoperiodic cycle. Serotonin increased locomotor activity only during the dark phase, while melatonin decreased locomotor activity only during the light phase.

Shivering and digestion-related thermogenesis in pigeons during dark phase

1999 ◽  
Vol 277 (6) ◽  
pp. R1579-R1587 ◽  
Author(s):  
Michael E. Rashotte ◽  
Seppo Saarela ◽  
Ross P. Henderson ◽  
Esa Hohtola
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Dark Phase ◽  
Restricted Feeding ◽  
Light Phase ◽  
Feeding Experiments ◽  
Food Load ◽  
Kinetics Of ◽  
Maintain Body Temperature ◽  
Shivering Thermogenesis

The pigeon's main source of regulated heat production, shivering, is especially likely to be used for thermoregulation during the dark phase of the day when there is little heat from locomotor activity. However, food stored in the pigeon's crop is digested during the night, and digestion-related thermogenesis (DRT) will provide heat that should decrease the need for shivering to maintain body temperature (Tb). We investigated the conditions under which DRT alters the occurrence of nocturnal shivering thermogenesis in pigeons. In fasting experiments, in which DRT was minimal, variations in pectoral shivering were closely related to the kinetics of nocturnal Tb when the ambient temperature (Ta) was moderate (21°C). In that case, shivering was low while Tb fell at the beginning of the night, moderate during the nocturnal plateau in Tb, and strong during the prelight increase in Tb. Similar kinetics of nocturnal Tb occurred when Ta = 28°C, but shivering was negligible throughout the dark phase. In restricted feeding experiments, nocturnal DRT was varied by providing different amounts of food late in the light phase. When Ta = 21°C, 11°C, and 1°C, nocturnal Tb and O2 consumption were directly related to the amount of food ingested. However, nocturnal shivering tended to decrease as the food load increased and was significantly reduced at the higher loads. Because nocturnal shivering did not become more efficient in producing heat as the size of the food load increased, we conclude that nocturnal DRT decreased the need for shivering thermogenesis.

Photoperiodic activity changes in juvenile sockeye salmon (Oncorhynchus nerka)

1971 ◽  
Vol 49 (8) ◽  
pp. 1155-1158 ◽  
Author(s):  
John E. Byrne
Keyword(s):  
Locomotor Activity ◽  
Environmental Conditions ◽  
Sockeye Salmon ◽  
Activity Rhythm ◽  
Oncorhynchus Nerka ◽  
Spontaneous Locomotor Activity ◽  
Active Response ◽  
Activity Rhythms

Spontaneous locomotor activity was studied in juvenile sockeye salmon under controlled environmental conditions (LD 9.5:14.5 or 12:12; 5 °C; 0.1–34.4 lux). Siblings were hatched in activity chambers and swimming movements were monitored with an ultrasonic system for 11 months. The experiments gave evidence of a bimodal activity rhythm in sockeye fry immediately after hatching. The bimodal, dark-active pattern persisted until 9 days after the fish emerged from the gravel. The photobehavioral response was reversed and the fish expressed a unimodal, light-active pattern 10–14 days after first emergence. This light-active response was then maintained for 11 months.The possible interrelationships between age, photobehavioral response, and activity rhythms underlying the sockeye fry migrations to nursery lakes are discussed.

scholarly journals Melatonin MT1 and MT2 Receptors Exhibit Distinct Effects in the Modulation of Body Temperature across the Light/Dark Cycle

2019 ◽  
Vol 20 (10) ◽  
pp. 2452 ◽  
Author(s):  
Martha López-Canul ◽  
Seung Hyun Min ◽  
Luca Posa ◽  
Danilo De Gregorio ◽  
Annalida Bedini ◽  
...  
Keyword(s):  
Body Temperature ◽  
Receptor Antagonist ◽  
Partial Agonist ◽  
Receptor Subtypes ◽  
Dark Phase ◽  
Light Phase ◽  
Dark Cycle ◽  
Simultaneous Activation ◽  
Type 3 ◽  
G Protein Coupled

Melatonin (MLT) is a neurohormone that regulates many physiological functions including sleep, pain, thermoregulation, and circadian rhythms. MLT acts mainly through two G-protein-coupled receptors named MT1 and MT2, but also through an MLT type-3 receptor (MT3). However, the role of MLT receptor subtypes in thermoregulation is still unknown. We have thus investigated the effects of selective and non-selective MLT receptor agonists/antagonists on body temperature (Tb) in rats across the 12/12-h light–dark cycle. Rectal temperature was measured every 15 min from 4:00 a.m. to 9:30 a.m. and from 4:00 p.m. to 9:30 p.m., following subcutaneous injection of each compound at either 5:00 a.m. or 5:00 p.m. MLT (40 mg/kg) had no effect when injected at 5 a.m., whereas it decreased Tb during the light phase only when injected at 5:00 p.m. This effect was blocked by the selective MT2 receptor antagonist 4P-PDOT and the non-selective MT1/MT2 receptor antagonist, luzindole, but not by the α1/MT3 receptors antagonist prazosin. However, unlike MLT, neither the selective MT1 receptor partial agonist UCM871 (14 mg/kg) nor the selective MT2 partial agonist UCM924 (40 mg/kg) altered Tb during the light phase. In contrast, UCM871 injected at 5:00 p.m. increased Tb at the beginning of the dark phase, whereas UCM924 injected at 5:00 a.m. decreased Tb at the end of the dark phase. These effects were blocked by luzindole and 4P-PDOT, respectively. The MT3 receptor agonist GR135531 (10 mg/kg) did not affect Tb. These data suggest that the simultaneous activation of both MT1 and MT2 receptors is necessary to regulate Tb during the light phase, whereas in a complex but yet unknown manner, they regulate Tb differently during the dark phase. Overall, MT1 and MT2 receptors display complementary but also distinct roles in modulating circadian fluctuations of Tb.

Resumption of anadromy or straying? Origins of Sockeye Salmon Oncorhynchus nerka in the Elwha River

2021 ◽  
Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Elwha River

Alternative Recruitment Models of Adams River Sockeye Salmon, Oncorhynchus nerka

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Status Quo ◽  
Management Policy ◽  
Best Management ◽  
Interaction Terms ◽  
Ricker Model ◽  
The Status ◽  
Stock Recruitment ◽  
High Yields

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.

Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice

2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Sea Lice

scholarly journals CCK-8 and CCK-58 differ in their effects on nocturnal solid meal pattern in undisturbed rats

2012 ◽  
Vol 303 (8) ◽  
pp. R850-R860 ◽  
Author(s):  
Miriam Goebel-Stengel ◽  
Andreas Stengel ◽  
Lixin Wang ◽  
Gordon Ohning ◽  
Yvette Taché ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Food Intake ◽  
Molecular Forms ◽  
Reduce Food Intake ◽  
Dark Phase ◽  
Sprague Dawley ◽  
Solid Meal ◽  
Sprague Dawley Rats ◽  
And Behavior

Various molecular forms of CCK reduce food intake in rats. Although CCK-8 is the most studied form, we reported that CCK-58 is the only detectable endocrine peptide form in rats. We investigated the dark-phase rat chow intake pattern following injection of CCK-8 and CCK-58. Ad libitum-fed male Sprague-Dawley rats were intraperitoneally injected with CCK-8, CCK-58 (0.6, 1.8, and 5.2 nmol/kg), or vehicle. Food intake pattern was assessed during the dark phase using an automated weighing system that allowed continuous undisturbed monitoring of physiological eating behavior. Both CCK-8 and CCK-58 dose dependently reduced 1-h, dark-phase food intake, with an equimolar dose of 1.8 nmol being similarly effective (−49% and −44%). CCK-58 increased the latency to the first meal, whereas CCK-8 did not. The intermeal interval was reduced after CCK-8 (1.8 nmol/kg, −41%) but not after CCK-58. At this dose, CCK-8 increased the satiety ratio by 80% and CCK-58 by 160%, respectively, compared with vehicle. When behavior was assessed manually, CCK-8 reduced locomotor activity (−31%), whereas grooming behavior was increased (+59%). CCK-58 affected neither grooming nor locomotor activity. In conclusion, reduction of food intake by CCK-8 and CCK-58 is achieved by differential modulation of food intake microstructure and behavior. These data highlight the importance of studying the molecular forms of peptides that exist in vivo in tissue and circulation of the animal being studied.

Validation of daily increments and a marine-entry check in the otoliths of sockeye salmon Oncorhynchus nerka post-smolts

2015 ◽  
Vol 87 (1) ◽  
pp. 169-178 ◽  
Author(s):  
C. Freshwater ◽  
M. Trudel ◽  
T. D. Beacham ◽  
C.-E. Neville ◽  
S. Tucker ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Daily Increments
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