Nonphotic phase-shifting in clock mutant mice.
Nonphotic phase-shifting was studied in mice bearing the Clock mutation. First, free-running mice heterozygous for Clock and wild-type mice were induced to become active through a 4-h confinement to a novel running over 3 days. Second, mice exposed to light-dark cycle received daily hypocaloric food during 2 weeks, before being transferred to constant darkness and fed ad libitum. Behavioral activation during the mid-subjective day induced 40-min phase advances in the locomotor activity rhythm of wild-type mice, whereas it produced 50-min phase delays in the circadian behavior of Clock/+ mice. Calorie restriction phase-advanced by 80 min the locomotor activity rhythm in wild-type mice, but not in Clock/+ mice. Therefore, the response of the Clock/+ mice to nonphotic phase shifting differs from that of wild-type mice.
Challet
E
E
Center for Circadian Biology and Medicine, Department of Neurobiology and Physiology, Northwestern University, 2153 North Campus Drive, Evanston, IL, USA. challet@neurochem.u-strasbg.fr
Takahashi
J S
JS
Turek
F W
FW
D000818:Animals; D056926:CLOCK Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D051379:Mice; D008818:Mice, Neurologic Mutants / Q000235:genetics*; D009043:Motor Activity / Q000502:physiology; D009154:Mutation / Q000235:genetics / Q000502:physiology*; D010775:Photic Stimulation; D013493:Suprachiasmatic Nucleus / Q000502:physiology*; D015534:Trans-Activators / Q000235:genetics* / Q000502:physiology
D015534:Trans-Activators; D056926:CLOCK Proteins; C538944:Clock protein, mouse