scholarly journals Body Temperature and Activity Rhythms Under Different Photoperiods in High Arctic Svalbard ptarmigan (Lagopus muta hyperborea)

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel Appenroth ◽  
Andreas Nord ◽  
David G. Hazlerigg ◽  
Gabriela C. Wagner
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Core Body Temperature ◽  
High Arctic ◽  
The Arctic ◽  
Constant Darkness ◽  
Polar Regions ◽  
Circadian Control ◽  
Polar Day ◽  
Lagopus Muta

Organisms use circadian rhythms to anticipate and exploit daily environmental oscillations. While circadian rhythms are of clear importance for inhabitants of tropic and temperate latitudes, its role for permanent residents of the polar regions is less well understood. The high Arctic Svalbard ptarmigan shows behavioral rhythmicity in presence of light-dark cycles but is arrhythmic during the polar day and polar night. This has been suggested to be an adaptation to the unique light environment of the Arctic. In this study, we examined regulatory aspects of the circadian control system in the Svalbard ptarmigan by recording core body temperature (Tb) alongside locomotor activity in captive birds under different photoperiods. We show that Tb and activity are rhythmic with a 24-h period under short (SP; L:D 6:18) and long photoperiod (LP; L:D 16:8). Under constant light and constant darkness, rhythmicity in Tb attenuates and activity shows signs of ultradian rhythmicity. Birds under SP also showed a rise in Tb preceding the light-on signal and any rise in activity, which proves that the light-on signal can be anticipated, most likely by a circadian system.

scholarly journals Photoperiodic induction without light-mediated circadian entrainment in a high arctic resident bird

2020 ◽  
Author(s):  
Daniel Appenroth ◽  
Vebjørn J. Melum ◽  
Alexander C. West ◽  
Hugues Dardente ◽  
David G. Hazlerigg ◽  
...  
Keyword(s):  
Activity Patterns ◽  
High Arctic ◽  
Gonadal Development ◽  
Photoperiodic Response ◽  
Day Length ◽  
The Arctic ◽  
Constant Light ◽  
Constant Darkness ◽  
Polar Regions ◽  
Lagopus Muta

AbstractOrganisms use changes in photoperiod to anticipate and exploit favourable conditions in a seasonal environment. While species living at temperate latitudes receive day length information as a year-round input, species living in the Arctic may spend as much as two-thirds of the year without experiencing dawn or dusk. This suggests that specialised mechanisms may be required to maintain seasonal synchrony in polar regions.Svalbard ptarmigan (Lagopus muta hyperborea) are resident at 74-81° north latitude. They spend winter in constant darkness (DD) and summer in constant light (LL); extreme photoperiodic conditions under which they do not display overt circadian rhythms.Here we explored how arctic adaptation in circadian biology affects photoperiodic time measurement in captive Svalbard ptarmigan. For this purpose, DD-adapted birds, showing no circadian behaviour, either remained in prolonged DD, were transferred into a simulated natural photoperiod (SNP) or were transferred directly into LL. Birds transferred from DD to LL exhibited a strong photoperiodic response in terms of activation of the hypothalamic thyrotropin-mediated photoperiodic response pathway. This was assayed through expression of the Eya3, Tshβ and deiodinase genes, as well as gonadal development. While transfer to SNP established synchronous diurnal activity patterns, activity in birds transferred from DD to LL showed no evidence of circadian rhythmicity.These data show that the Svalbard ptarmigan does not require circadian entrainment to develop a photoperiodic response involving conserved molecular elements found in temperate species. Further studies are required to define how exactly arctic adaptation modifies seasonal timer mechanisms.Summary statementSvalbard ptarmigan show photoperiodic responses when transferred from constant darkness to constant light without circadian entrainment.

scholarly journals Photoperiodic induction without light-mediated circadian entrainment in a High Arctic resident bird

2020 ◽  
Vol 223 (16) ◽  
pp. jeb220699 ◽  
Author(s):  
Daniel Appenroth ◽  
Vebjørn J. Melum ◽  
Alexander C. West ◽  
Hugues Dardente ◽  
David G. Hazlerigg ◽  
...  
Keyword(s):  
Activity Patterns ◽  
High Arctic ◽  
Gonadal Development ◽  
Photoperiodic Response ◽  
Day Length ◽  
The Arctic ◽  
Constant Darkness ◽  
Polar Regions ◽  
Natural Photoperiod ◽  
Lagopus Muta

ABSTRACTOrganisms use changes in photoperiod to anticipate and exploit favourable conditions in a seasonal environment. While species living at temperate latitudes receive day length information as a year-round input, species living in the Arctic may spend as much as two-thirds of the year without experiencing dawn or dusk. This suggests that specialised mechanisms may be required to maintain seasonal synchrony in polar regions. Svalbard ptarmigan (Lagopus muta hyperborea) are resident at 74–81°N latitude. They spend winter in constant darkness (DD) and summer in constant light (LL); extreme photoperiodic conditions under which they do not display overt circadian rhythms. Here, we explored how Arctic adaptation in circadian biology affects photoperiodic time measurement in captive Svalbard ptarmigan. For this purpose, DD-adapted birds, showing no circadian behaviour, either remained in prolonged DD, were transferred into a simulated natural photoperiod (SNP) or were transferred directly into LL. Birds transferred from DD to LL exhibited a strong photoperiodic response in terms of activation of the hypothalamic thyrotropin-mediated photoperiodic response pathway. This was assayed through expression of the Eya3, Tshβ and deiodinase genes, as well as gonadal development. While transfer to SNP established synchronous diurnal activity patterns, activity in birds transferred from DD to LL showed no evidence of circadian rhythmicity. These data show that the Svalbard ptarmigan does not require circadian entrainment to develop a photoperiodic response involving conserved molecular elements found in temperate species. Further studies are required to define how exactly Arctic adaptation modifies seasonal timer mechanisms.

scholarly journals Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels

2011 ◽  
Vol 8 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Cory T. Williams ◽  
Brian M. Barnes ◽  
C. Loren Buck
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Ground Squirrels ◽  
The Arctic ◽  
Constant Light ◽  
Polar Regions ◽  
Free Living ◽  
Active Season ◽  
Temperature Rhythms ◽  
Arctic Ground Squirrels

In indigenous arctic reindeer and ptarmigan, circadian rhythms are not expressed during the constant light of summer or constant dark of winter, and it has been hypothesized that a seasonal absence of circadian rhythms is common to all vertebrate residents of polar regions. Here, we show that, while free-living arctic ground squirrels do not express circadian rhythms during the heterothermic and pre-emergent euthermic intervals of hibernation, they display entrained daily rhythms of body temperature ( T b ) throughout their active season, which includes six weeks of constant sun. In winter, ground squirrels are arrhythmic and regulate core body temperatures to within ±0.2°C for up to 18 days during steady-state torpor. In spring, after the use of torpor ends, male but not female ground squirrels, resume euthermic levels of T b in their dark burrows but remain arrhythmic for up to 27 days. However, once activity on the surface begins, both sexes exhibit robust 24 h cycles of body temperature. We suggest that persistence of nycthemeral rhythms through the polar summer enables ground squirrels to minimize thermoregulatory costs. However, the environmental cues (zeitgebers) used to entrain rhythms during the constant light of the arctic summer in these semi-fossorial rodents are unknown.

Impairment of heme biosynthesis induces short circadian period in body temperature rhythms in mice

2012 ◽  
Vol 303 (1) ◽  
pp. R8-R18 ◽  
Author(s):  
Reiko Iwadate ◽  
Yoko Satoh ◽  
Yukino Watanabe ◽  
Hiroshi Kawai ◽  
Naomi Kudo ◽  
...  
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Core Body Temperature ◽  
Intraperitoneal Administration ◽  
Biological Rhythms ◽  
Heme Biosynthesis ◽  
Diurnal Rhythms ◽  
Phase Advance ◽  
Constant Darkness ◽  
Acute Porphyria

It has been demonstrated that the function of mammalian clock gene transcripts is controlled by the binding of heme in vitro. To examine the effects of heme on biological rhythms in vivo, we measured locomotor activity (LA) and core body temperature (Tb) in a mouse model of porphyria with impaired heme biosynthesis by feeding mice a griseofulvin (GF)-containing diet. Mice fed with a 2.0% GF-containing diet (GF2.0) transiently exhibited phase advance or phase advance-like phenomenon by 1–3 h in terms of the biological rhythms of Tbor LA, respectively (both, P < 0.05) while mice were kept under conditions of a light/dark cycle (12 h:12 h). We also observed a transient, ∼0.3 h shortening of the period of circadian Tbrhythms in mice kept under conditions of constant darkness ( P < 0.01). Interestingly, the observed duration of abnormal circadian rhythms in GF2.0 mice lasted between 1 and 3 wk after the onset of GF ingestion; this finding correlated well with the extent of impairment of heme biosynthesis. When we examined the effects of therapeutic agents for acute porphyria, heme, and hypertonic glucose on the pathological status of GF2.0 mice, it was found that the intraperitoneal administration of heme (10 mg·kg−1·day−1) or glucose (9 g·kg−1·day−1) for 7 days partially reversed (50%) increases in urinary δ-aminolevulinic acids levels associated with acute porphyria. Treatment with heme, but not with glucose, suppressed the phase advance (-like phenomenon) in the diurnal rhythms ( P < 0.05) and restored the decrease of heme ( P < 0.01) in GF2.0 mice. These results suggest that impairments of heme biosynthesis, in particular a decrease in heme, may affect phase and period of circadian rhythms in animals.

Ambulatory Estimation of Circadian Rhythms Shows Core Body Temperature Phase Precedes Slow Wave Sleep Phase in the Normal Elderly

2020 ◽  
Vol 87 (9) ◽  
pp. S251
Author(s):  
Esther Blessing ◽  
Ankit Paresh ◽  
Arleener Turner ◽  
Andrew Varga ◽  
David Rapoport ◽  
...  
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
Core Body Temperature ◽  
Temperature Phase ◽  
Sleep Phase ◽  
Core Body

Organization of rat circadian rhythms during daily infusion of melatonin or S20098, a melatonin agonist

1999 ◽  
Vol 277 (3) ◽  
pp. R812-R828 ◽  
Author(s):  
B. Pitrosky ◽  
R. Kirsch ◽  
A. Malan ◽  
E. Mocaer ◽  
P. Pevet
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Phase Response Curve ◽  
Constant Darkness ◽  
Time Interval ◽  
General Activity ◽  
Activity Peak ◽  
Free Running ◽  
Wheel Activity ◽  
Free Running Period

Daily administration of melatonin or S20098, a melatonin agonist, is known to entrain the free-running circadian rhythms of rats. The effects of the duration of administration on entrainment were studied. The animals demonstrated free-running circadian rhythms (running-wheel activity, body temperature, general activity) in constant darkness. Daily infusions of melatonin or S20098 for 1, 8, or 16 h entrained the circadian rhythms to 24 h. Two daily infusions of 1 h (separated by 8 h) entrained the activity peak within the shorter time interval. The entraining properties of melatonin and S20098 were similar and were affected neither by pinealectomy nor by infusion of 1- or 8-h duration. However, with 16-h infusion, less than half of the animals became entrained. Once entrained, the phase angle between the onset of infusion and the rhythms (onset of activity or acrophase of body temperature) increased with the duration of infusion. Before entrainment, the free-running period increased with the duration of infusion, an effect that was not predictable from the phase response curve.

scholarly journals Masking Effects of Posture and Sleep Onset on Core Body Temperature Have Distinct Circadian Rhythms: Results from a 90-Min/Day Protocol

2002 ◽  
Vol 17 (5) ◽  
pp. 447-462 ◽  
Author(s):  
Douglas E. Moul ◽  
Hernando Ombao ◽  
Timothy H. Monk ◽  
Qingxia Chen ◽  
Daniel J. Buysse
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Core Body Temperature ◽  
Sleep Onset ◽  
Core Body

scholarly journals Adaptive value of circadian rhythms in High Arctic Svalbard ptarmigan

2020 ◽  
Author(s):  
Daniel Appenroth ◽  
Gabriela C. Wagner ◽  
David G. Hazlerigg ◽  
Alexander C. West
Keyword(s):  
Circadian Rhythms ◽  
Circadian Clock ◽  
Activity Patterns ◽  
Bird Species ◽  
High Arctic ◽  
Photoperiodic Response ◽  
The Arctic ◽  
Pars Tuberalis ◽  
Clock Gene Expression ◽  
Adaptive Value

SUMMARYThe arctic archipelago of Svalbard (74 to 81° North) experiences extended periods of uninterrupted daylight in summer and uninterrupted darkness in winter. Species native to Svalbard display no daily rhythms in behaviour or physiology during these seasons, leading to the view that circadian rhythms may be redundant in arctic environments [1, 2]. Nevertheless, seasonal changes in the physiology and behaviour of arctic species rely on photoperiodic synchronisation to the solar year. Since this phenomenon is generally circadian-based in temperate species, we investigated if this might be a preserved aspect of arctic temporal organisation.Here, we demonstrate the involvement of the circadian clock in the seasonal photoperiodic response of the Svalbard ptarmigan (Lagopus muta hyperborea), the world’s northernmost resident bird species. First, we show the persistence of rhythmic clock gene expression under constant conditions within the mediobasal hypothalamus and pars tuberalis, the key tissues in the seasonal neuroendocrine cascade. We then employ a “sliding skeleton photoperiod” protocol, revealing that the driving force behind seasonal biology of the Svalbard ptarmigan is rhythmic sensitivity to light, a feature that depends on a functioning circadian rhythm. Our results suggest that the unusual selective pressure of the Arctic relaxes the adaptive value of the circadian clock for organisation of daily activity patterns, whilst preserving its importance for seasonal synchronisation. Thus, our data simultaneously reconnects circadian rhythms to life in the Arctic and establishes a universal principle of evolutionary value for circadian rhythms in seasonal biology.

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