scholarly journals Circadian rhythms and locomotor activity of smolts of the european river lamprey lampetra fluviatilis (l.)

2019 ◽  
Vol 484 (2) ◽  
pp. 243-246
Author(s):  
A. O. Zvezdin ◽  
D. S. Pavlov ◽  
A. V. Kucheryavyy ◽  
I. A. Tsimbalov
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Channel Flow ◽  
Downstream Migration ◽  
Nocturnal Activity ◽  
Lampetra Fluviatilis ◽  
River Lamprey ◽  
The Individual ◽  
Short Time

Locomotor activity was investigated in smolts of the European river lamprey at alternation of light and darkness (12/12 h) and in the dark. Two groups of smolts were discerned differing in the level of locomotor activity. The presence of the circadian rhythm in smolts has been revealed, and its role in downstream migration has been shown. The locomotor activity leading smolts to channel flow increases with decreasing illumination at evening twilight. The period of high nocturnal activity is completed a short time before morning twilight, under the action of the individual circadian rhythm. This decreases the probability of impact of predators on migrating smolts.

Circadian Rhythms and Locomotor Activity of Smolts of the European River Lamprey Lampetra fluviatilis (L.)

2019 ◽  
Vol 484 (1) ◽  
pp. 16-18 ◽  
Author(s):  
A. O. Zvezdin ◽  
D. S. Pavlov ◽  
A. V. Kucheryavyy ◽  
I. A. Tsimbalov
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Lampetra Fluviatilis ◽  
River Lamprey

scholarly journals Experimental study of the European river lamprey Lampetra fluviatilis (L.) downstream migrating smolts rheoreaction under various illuminations

2019 ◽  
Vol 487 (4) ◽  
pp. 469-472
Author(s):  
A. O. Zvezdin ◽  
D. S. Pavlov ◽  
I. A. Tsimbalov ◽  
A. V. Kucheryavyy
Keyword(s):  
Experimental Study ◽  
Active Form ◽  
Downstream Migration ◽  
Natural Conditions ◽  
Experimental Conditions ◽  
Lampetra Fluviatilis ◽  
River Lamprey

Rheoreaction of the downstream migrating smolts of the European river lamprey was studied in the experimental conditions at illuminations of day and night intensity. It was found that at the daytime the smolts are mostly dormant and if move downstream then in active-passive form (with the head against the stream, and their speed going beyond the velocity). This data is well within the findings on the night downstream migration of the smolts during the 24 h period in natural conditions. Thus, the downstream migration of the smolts has an active form.

scholarly journals Magnetic fluctuations affect circadian patterns of locomotor activity in zebrafish

2021 ◽  
Author(s):  
Viacheslav V. Krylov ◽  
Evgeny I. Izvekov ◽  
Vera V. Pavlova ◽  
Natalia A. Pankova ◽  
Elena A. Osipova
Keyword(s):  
Magnetic Field ◽  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Danio Rerio ◽  
Magnetic Fluctuations ◽  
Constant Illumination ◽  
Free Running ◽  
Circadian Patterns

AbstractThe locomotor activity of zebrafish (Danio rerio) has a pronounced, well-studied circadian rhythm. Under constant illumination, the period of free-running locomotor activity in this species usually becomes less than 24 hours. To evaluate the entraining capabilities of slow magnetic variations, zebrafish locomotor activity was evaluated at constant illumination and fluctuating magnetic field with a period of 26.8 hours. Lomb-Scargle periodogram revealed significant free-running rhythms of locomotor activity and related behavioral endpoints with a period close to 27 hours. Obtained results reveal the potential of slow magnetic fluctuations for entrainment of the circadian rhythms in zebrafish. The putative mechanisms responsible for the entrainment are discussed, including the possible role of cryptochromes.

Circadian rhythms of rabbits during restrictive feeding

1987 ◽  
Vol 253 (1) ◽  
pp. R46-R54 ◽  
Author(s):  
B. Jilge ◽  
H. Hornicke ◽  
H. Stahle
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Food Access ◽  
Feeding Time ◽  
Restricted Feeding ◽  
Small Component ◽  
Physiological Functions ◽  
System A ◽  
Free Running

Without a zeitgeber the circadian rhythms of five physiological functions free-ran with a period length greater than 24 h. Restricted feeding time (RF) masked the free-running rhythms. In addition to masking, entrainment with RF occurred. This process was most evident in locomotor activity and visits to the food box. RF thus had zeitgeber properties in these rabbits. However, in most rabbits the RF zeitgeber was not strong enough to entrain the circadian rhythm completely. A small component free-ran during RF. Following return to continuous food access the whole circadian rhythm resumed to free-run again. In some animals its phase was determined by the RF zeitgeber and in others by the small free-running fraction present during RF. The results suggest that in addition to the light-dark-entrainable circadian oscillator system a feeding-entrainable oscillator exists that takes over phase control of the majority of the rhythm during RF.

Endogenous ultradian rhythms in rats exposed to prolonged continuous light

1978 ◽  
Vol 235 (5) ◽  
pp. R250-R256 ◽  
Author(s):  
K. I. Honma ◽  
T. Hiroshige
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Continuous Light ◽  
Plasma Corticosterone ◽  
Ultradian Rhythm ◽  
Ultradian Rhythms ◽  
Serial Sampling ◽  
Free Running

Circadian rhythms of locomotor activity, body temperature, and plasma corticosterone were determined simultaneously in individual rats that were exposed to 200 lx continuous light for over 3 mo. Free-running circadian rhythms of locomotor activity persisted for about 2 mo under continuous light and then the rhythms gradually decomposed. After 3 mo of exposure, circadian rhythms disappeared and activity bursts of 1- to 2-h duration manifested themselves several times during a 24-h period. Body temperature also exhibited several bursts of fluctuation and these bursts were closely correlated in their temporal sequence with those of locomotor activity. A least-squares spectrum analysis revealed that the burst had regular 4- to 6-h periods. Plasma corticosterone, determined by serial sampling at 2-h intervals from individual rats, also exhibited several secretion episodes in a day. These episodic secretions synchronized with bursts of locomotor activity. These results suggest that the ultradian component, manifested under prolonged continuous light, is a fundamental unit of the circadian rhythm and an oscillator for the ultradian rhythm is common to the three functions examined.

Temporal characteristics of downstream migration of smolts of the European river lamprey Lampetra fluviatilis in the Chernaya River

2017 ◽  
Vol 44 (3) ◽  
pp. 290-295 ◽  
Author(s):  
D. S. Pavlov ◽  
A. O. Zvezdin ◽  
V. V. Kostin ◽  
I. A. Tsimbalov ◽  
A. V. Kucheryavyy
Keyword(s):  
Downstream Migration ◽  
Lampetra Fluviatilis ◽  
Temporal Characteristics ◽  
River Lamprey

Hormonal and locomotor activity rhythms in rats under 90-min dark-pulse conditions

1993 ◽  
Vol 264 (6) ◽  
pp. R1058-R1064
Author(s):  
M. L. Laakso ◽  
T. Porkka-Heiskanen ◽  
L. Leinonen ◽  
S. L. Joutsiniemi ◽  
P. T. Mannisto
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Serum Levels ◽  
Thyroid Stimulating Hormone ◽  
Diurnal Variations ◽  
Serum Corticosterone ◽  
Pineal Melatonin ◽  
Free Running ◽  
Dark Pulse

The ability of a short dark pulse to entrain the circadian rhythms in rats was investigated. Pineal melatonin contents and serum levels of corticosterone and thyrotropin, a thyroid-stimulating hormone (TSH), were measured and locomotor activity was recorded under 12:12-h light-dark cycles (LD; darkness from 1800 to 0600 h) and under a 22.5:1.5 h LD lighting schedule (darkness from 1800 to 1930 h). The 90-min dark pulse was enough to trigger the rise of melatonin synthesis, but a free-running component was detected in the locomotor activity. Corticosterone levels showed diurnal variations under both conditions. The decrease of corticosterone and the increase of melatonin were phase locked, but the corticosterone pattern was distorted under the dark-pulse conditions. The 24-h rhythm of TSH was detectable in the control but not in the dark-pulse schedule. The results suggest that the circadian rhythm of pineal melatonin and the decrease of serum corticosterone levels were entrainable by the dark pulses, whereas the increase of corticosterone, the variations of TSH, and the rhythm of locomotor activity were not.

Downstream migration of early larvae of the European river lamprey Lampetra fluviatilis

2014 ◽  
Vol 459 (1) ◽  
pp. 344-347 ◽  
Author(s):  
D. S. Pavlov ◽  
D. Yu. Nazarov ◽  
A. O. Zvezdin ◽  
A. V. Kucheryavyi
Keyword(s):  
Downstream Migration ◽  
Lampetra Fluviatilis ◽  
River Lamprey ◽  
Early Larvae
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