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Author (up) Raiewski, E.E.; Elliott, J.A.; Evans, J.A.; Glickman, G.L.; Gorman, M.R.
Title Twice daily melatonin peaks in Siberian but not Syrian hamsters under 24 h light:dark:light:dark cycles Type Journal Article
Year 2012 Publication Chronobiology International Abbreviated Journal Chronobiol Int
Volume 29 Issue 9 Pages 1206-1215
Keywords Animals; Circadian Rhythm/*physiology; Cricetinae; Male; Melatonin/blood/*secretion; Mesocricetus/blood/*physiology; Motor Activity/physiology; Phodopus/blood/*physiology; Photoperiod; Species Specificity
Abstract The daily pattern of blood-borne melatonin varies seasonally under the control of a multi-oscillator circadian pacemaker. Here we examine patterns of melatonin secretion and locomotor activity in Siberian and Syrian hamsters entrained to bimodal LDLD8:4:8:4 and LD20:4 lighting schedules that facilitate novel temporal arrangements of component circadian oscillators. Under LDLD, both species robustly bifurcated wheel-running activity in distinct day scotophase (DS) and night scotophase (NS) bouts. Siberian hamsters displayed significant melatonin increases during each scotophase in LDLD, and in the single daily scotophase of LD20:4. The bimodal melatonin secretion pattern persisted in acutely extended 16 h scotophases. Syrian hamsters, in contrast, showed no significant increases in plasma melatonin during either scotophase of LDLD8:4:8:4 or in LD20:4. In this species, detectable levels were observed only when the DS of LDLD was acutely extended to yield 16 h of darkness. Established species differences in the phase lag of nocturnal melatonin secretion relative to activity onset may underlie the above contrast: In non-bifurcated entrainment to 24 h LD cycles, Siberian hamsters show increased melatonin secretion within approximately 2 h after activity onset, whereas in Syrian hamsters, detectable melatonin secretion phase lags activity onset and the L/D transition by at least 4 h. The present results provide new evidence indicating multi-oscillator regulation of the waveform of melatonin secretion, specifically, the circadian control of the onset, offset and duration of nocturnal secretion.
Address Department of Psychology, and Center for Chronobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0109, USA. eraiewski@ucsd.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0742-0528 ISBN Medium
Area Expedition Conference
Notes PMID:23003567 Approved no
Call Number IDA @ john @ Serial 85
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Author (up) Rotics, S.; Dayan, T.; Kronfeld-Schor, N.
Title Effect of artificial night lighting on temporally partitioned spiny mice Type Journal Article
Year 2011 Publication Journal of Mammalogy Abbreviated Journal Journal of Mammalogy
Volume 92 Issue 1 Pages 159-168
Keywords mice; animals; mammals; Acomys cahirinus; Acomys russatus; activity patterns; light night niche; light pollution
Abstract We studied the effect of ecological light pollution on a rocky desert community, focusing on 2 spiny mouse congeners, nocturnal Acomys cahirinus (common spiny mouse) and diurnal Acomys russatus (golden spiny mouse). We hypothesized that in response to artificial illumination A. cahirinus will decrease its activity and A. russatus will increase its activity, and thus temporal overlap and interspecific competition could increase. Our study took place in 4 field enclosures: the 1st and 3rd months were controls with natural light, and in the 2nd month artificial illumination, simulating low levels of light pollution, was set for the first 3 h of the night. We implanted temperature-sensitive radiotransmitters to monitor mouse activity, and individual identification tags with automonitored foraging patches were used to track foraging behavior. A. cahirinus decreased activity and foraging with artificial lighting, restricting movement particularly in less-sheltered microhabitats, probably because of increased predation risk. Because illumination restricted both activity time and space, intraspecific encounters of A. cahirinus over foraging patches increased during and following the illuminated hours. However, diurnal A. russatus did not expand its activity into the illuminated hours, possibly due to the presence of competing A. cahirinus, or to nonfavorable environmental conditions. Therefore, overt interspecific competition was not affected by experimental light pollution. Light pollution had a negative influence by reducing overall activity and producing a relatively underexploited temporal niche, which may promote invasion of alien species that are less light sensitive; and by increasing intraspecific overlap in foraging A. cahirinus.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2372 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 86
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Author (up) Saldaña-Vázquez, R.A.; Munguía-Rosas, M.A.
Title Lunar phobia in bats and its ecological correlates: A meta-analysis Type Journal Article
Year 2013 Publication Mammalian Biology – Zeitschrift für Säugetierkunde Abbreviated Journal Mammalian Biology – Zeitschrift für Säugetierkunde
Volume 78 Issue 3 Pages 216-219
Keywords Chiroptera; Foraging activity; Foraging habitat; Latitude; Moonlight; mammals; bats; animals
Abstract Animals show several behavioral strategies to reduce predation risks. Presumably, moonlight avoidance is a strategy used by some nocturnal species to reduce the risk of predation. In bats, some research indicates that foraging activity is negatively correlated with moonlight intensity, a phenomenon better known as lunar phobia. However, the currently available evidence is contradictory because some bat species reduce their activity during nights with more moonlight while the opposite occurs in other species. We quantitatively evaluated the strength and direction of the relationship between moonlight intensity and bat activity using a meta-analysis. We also looked at some ecological correlates of lunar phobia in bats. Specifically, we examined foraging habitat and latitude as potential moderators of the size of the lunar phobia effect. Our results show that, regardless of the method used to evaluate bat activity, the overall relationship between moonlight intensity and bat activity is significant and negative (r = −0.22). Species foraging on the surface of the water (piscivores and insectivores; r = −0.83) and forest canopy species (i.e., big frugivores; r = −0.30) are more affected by moonlight than those with different foraging habitats (understory, subcanopy, open air). Latitude was positively correlated with lunar phobia (r = 0.023). The stronger lunar phobia for bats foraging on the water surface and in the forest canopy may suggest that the risk of predation is greater where moonlight penetrates more easily. The significant effect of latitude as a moderator of lunar phobia suggests that there is a weak geographic pattern, with this phobia slightly more common in tropical bats than in temperate species.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-5047 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 97
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Author (up) Sherman, H.; Gutman, R.; Chapnik, N.; Meylan, J.; le Coutre, J.; Froy, O.
Title Caffeine alters circadian rhythms and expression of disease and metabolic markers Type Journal Article
Year 2011 Publication The International Journal of Biochemistry & Cell Biology Abbreviated Journal Int J Biochem Cell Biol
Volume 43 Issue 5 Pages 829-838
Keywords Human Health; Animals; Biological Markers/blood/metabolism; Body Weight/drug effects/physiology; Caffeine/*pharmacology; Caloric Restriction; Circadian Rhythm/*drug effects/genetics/physiology; *Disease/genetics; Eating/drug effects/physiology; Gene Expression Regulation/*drug effects/genetics; HEK293 Cells; Humans; Inflammation/metabolism; Male; Mice; Mice, Inbred C57BL; Motor Activity/drug effects/physiology
Abstract The circadian clock regulates many aspects of physiology, energy metabolism, and sleep. Restricted feeding (RF), a regimen that restricts the duration of food availability entrains the circadian clock. Caffeine has been shown to affect both metabolism and sleep. However, its effect on clock gene and clock-controlled gene expression has not been studied. Here, we tested the effect of caffeine on circadian rhythms and the expression of disease and metabolic markers in the serum, liver, and jejunum of mice supplemented with caffeine under ad libitum (AL) feeding or RF for 16 weeks. Caffeine significantly affected circadian oscillation and the daily levels of disease and metabolic markers. Under AL, caffeine reduced the average daily mRNA levels of certain disease and inflammatory markers, such as liver alpha fetoprotein (Afp), C-reactive protein (Crp), jejunum alanine aminotransferase (Alt), growth arrest and DNA damage 45beta (Gadd45beta), Interleukin 1alpha (Il-1alpha), Il-1beta mRNA and serum plasminogen activator inhibitor 1 (PAI-1). Under RF, caffeine reduced the average daily levels of Alt, Gadd45beta, Il-1alpha and Il-1beta mRNA in the jejunum, but not in the liver. In addition, caffeine supplementation led to decreased expression of catabolic factors under RF. In conclusion, caffeine affects circadian gene expression and metabolism possibly leading to beneficial effects mainly under AL feeding.
Address Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1357-2725 ISBN Medium
Area Expedition Conference
Notes PMID:21352949 Approved no
Call Number LoNNe @ kagoburian @ Serial 810
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Author (up) Sinam, B.; Sharma, S.; Thakurdas, P.; Joshi, D.S.
Title Bright photophase accelerates re-entrainment after experimental jetlag in Drosophila Type Journal Article
Year 2012 Publication Die Naturwissenschaften Abbreviated Journal Naturwissenschaften
Volume 99 Issue 7 Pages 575-578
Keywords Animals; Circadian Rhythm/*physiology; Drosophila/*physiology/*radiation effects; *Light; Motor Activity/physiology; *Photoperiod
Abstract The efficacy of bright photophase (BP) in accelerating the re-entrainment of Drosophila biarmipes rhythm following 8 h phase advance and delay of light-dark (LD) cycle was examined by subjecting the flies to 24 h LD cycles with dim photophase (DP) at 30 lx and BP at 300 lx. Re-entrainment was analysed by using the activity onset, activity offset and the duration of activity. Following LD advance or delay, the BP flies re-entrained faster than the DP flies which was attributed to the enhanced zeitgeber strength of BP. Nevertheless, the re-entrainment was a protracted process even in the BP flies since the activity offsets underwent more transients than the activity onsets. Thus, this study demonstrates that the BP accelerates the re-entrainment in D. biarmipes. It, however, also reveals that the re-entrainment is a prolonged process when the activity onset and offset are regarded as the rhythm markers.
Address Center for Biological Rhythm Research, Ahmednagar College, Ahmednagar, 414001, MS, India
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-1042 ISBN Medium
Area Expedition Conference
Notes PMID:22684252 Approved no
Call Number IDA @ john @ Serial 109
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