toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Gorman, M. R.; Elliott, J. A. url  doi
openurl 
  Title Dim nocturnal illumination alters coupling of circadian pacemakers in Siberian hamsters, Phodopus sungorus Type Journal Article
  Year 2004 Publication Journal of Comparative Physiology A Abbreviated Journal Comp Physiol A  
  Volume (up) 190 Issue 8 Pages 631-  
  Keywords animals; rodents; seasonal timing  
  Abstract The circadian pacemaker of mammals comprises multiple oscillators that may adopt different phase relationships to determine properties of the coupled system. The effect of nocturnal illumination comparable to dim moonlight was assessed in male Siberian hamsters exposed to two re-entrainment paradigms believed to require changes in the phase relationship of underlying component oscillators. In experiment 1, hamsters were exposed to a 24-h light-dark-light-dark cycle previously shown to split circadian rhythms into two components such that activity is divided between the two daily dark periods. Hamsters exposed to dim illumination (<0.020 lx) during each scotophase were more likely to exhibit split rhythms compared to hamsters exposed to completely dark scotophases. In experiment 2, hamsters were transferred to winter photoperiods (10 h light, 14 h dark) from two different longer daylengths (14 h or 18 h light daily) in the presence or absence of dim nighttime lighting. Dim nocturnal illumination markedly accelerated adoption of the winter phenotype as reflected in the expansion of activity duration, gonadal regression and weight loss. The two experiments demonstrate substantial efficacy of light intensities generally viewed as below the threshold of circadian systems. Light may act on oscillator coupling through rod-dependent mechanisms.  
  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 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ schroer @ Serial 1590  
Permanent link to this record
 

 
Author Ikeda, Masayuki; Sagara, Masami; Inoué, Shojiro url  doi
openurl 
  Title Continuous exposure to dim illumination uncouples temporal patterns of sleep, body temperature, locomotion and drinking behavior in the rat Type Journal Article
  Year 2000 Publication Neuroscience Letters Abbreviated Journal  
  Volume (up) 279 Issue 3 Pages 185-189  
  Keywords animals; rodents; animal behaviour  
  Abstract Dissociable circadian rhythms of sleep and body temperature in primates are thought to be regulated by independent oscillators whereas the uncoupling of circadian rhythms has not been well described in other mammals. Therefore, we made simultaneous recordings of non-rapid-eye-movement-sleep (NREMS), rapid-eye-movement-sleep (REMS), brain temperature, intraperitoneal temperature, locomotion and drinking activity under light-dark (LD) and continuous dim illumination (dim LL) and analyzed their interrelations. The rhythmic patterns of body temperature, locomotion and drinking were modified on the 12th circadian day of dim LL, while the mean body temperature as well as mean occurrence of drinking and locomotor activities did not change significantly. In contrast, dim LL exposure significantly increased the total time spent in NREMS during the resting phase of dim LL and increased REMS episodes during the active phase of dim LL. The diverse effects of dim LL exposure on the recorded phenomena suggest that temporal patterns of sleep were the most sensitive to perturbations of lighting and that differential oscillatory mechanisms may regulate sleep and other circadian rhythms in the rat.  
  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 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ schroer @ Serial 1591  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: