PMID- 700901
OWN - NLM
STAT- MEDLINE
DCOM- 19781227
LR  - 20061115
IS  - 0300-9998 (Print)
IS  - 0300-9998 (Linking)
VI  - 5
IP  - 4
DP  - 1978
TI  - Comparative aspects of circadian rhythms in homeotherms, re-entrainment after 
      phase shifts of the zeitgeber.
PG  - 493-517
AB  - Re-entrainment of circadian activity of 3 avian species (Fringillidae: Fringilla 
      coelebs, Carduelis chloris, Pyrrhula pyrrhula) and 4 mammalian species (Rodentia: 
      Eutamias sibiricus, Funambulus pennanti, Glis glis, Mesocricetus auratus), 
      subjected to 12:12 h light-dark (LD) cycles as zeitgeber, was studied after 
      shifting the LD cycle by different amounts (hours) and in different directions 
      (advances and delays). The properties of the zeitgeber were changed by varying 
      light intensity during dark-time (ID) and/or light-time (IL). After 6 and 9-h 
      advance and delay shifts of the LD cycle, the 3 species of finches similarly 
      re-entrained their activity rhythms in the direction of the shifted zeitgeber. 
      After 10.5 and 12-h shifts, the majority of individuals re-entrained by delay 
      phase shifts of the rhythms. After two successive 6-h advance or delay shifts 
      (resulting in inversion of the LD cycle) most finches responded by advances. 
      Generally, the time needed for re-entrainment of 2/3 of the full shift (2/3 tr) 
      in finches dependend on: (a) the direction of the phase shift ('asymmetry 
      effect'), and (b) the phase-angle difference between onset of activity and 
      light-on (psio) before the shift. After 12-h shifts, species-specific differences 
      in the direction of re-entrainment and in the slope of the relationship between 
      2/3 tr and psio were found. In two rodents, the nocturnal golden hamster and the 
      diurnal Siberian chipmunk, the direction of re-entrainment following inversion of 
      the LD cycle depended on psio. In both species, 2/3 tr after inversion of the 
      zeitgeber was significantly longer than in the common dormouse. In chipmunks, 
      changes in 2/3 tr were correlated with changes in psio due to systematic 
      variation of the zeitgeber properties (range and/or mean level). After 6-h phase 
      shifts, the 'asymmetry effect' was opposite in the two nocturnal rodents, the 
      hamster and the dormouse. It is suggested that the time course (direction and 
      rate) of re-entrainment was influenced by differences in the characteristics of 
      the circadian systems and their responses ('sensitivity') to light changes in the 
      various species of birds and mammals.
FAU - Pohl, H
AU  - Pohl H
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - England
TA  - Int J Chronobiol
JT  - International journal of chronobiology
JID - 0367714
SB  - IM
MH  - Animals
MH  - *Biological Clocks
MH  - Birds/*physiology
MH  - *Circadian Rhythm
MH  - Light
MH  - Motor Activity/physiology
MH  - Rodentia/*physiology
MH  - Species Specificity
EDAT- 1978/01/01 00:00
MHDA- 1978/01/01 00:01
CRDT- 1978/01/01 00:00
PHST- 1978/01/01 00:00 [pubmed]
PHST- 1978/01/01 00:01 [medline]
PHST- 1978/01/01 00:00 [entrez]
PST - ppublish
SO  - Int J Chronobiol. 1978;5(4):493-517.