Activity in anticipation and in succession of a daily meal.
When exposed, in otherwise constant conditions, to a schedule with one single meal per day, rodents anticipate the time of food availability by an increase in locomotor activity while the main circadian rhythm continues to free-run with a period different from 24 h. The anticipatory activity (AA) is considered a component which is uncoupled from the light-entrainable circadian system and controlled by a food-entrainable oscillator. In this report it is shown that, in addition to AA, sometimes a burst or band of activity appears which succeeds the feeding time (SA). AA and SA seem to belong to one another, both being controlled by the same food-entrainable oscillator. The band of activity constituted by the combination of both AA and SA, though temporarily suppressed during and immediately after the meal, follows, as a whole, the rules of entrainment as known from circadian systems.
Max-Planck-Institut für Verhaitemsphysiologie Andechs, Federal Republic of Germany.
J
J
Aschoff
D000818:Animals; D001683:Biological Clocks / Q000502:physiology; D001717:Birds / Q000502:physiology*; D002171:Canaries / Q000502:physiology; D002940:Circadian Rhythm; D003214:Conditioning, Classical; D005247:Feeding Behavior / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D010775:Photic Stimulation; D051381:Rats / Q000502:physiology*; D013997:Time Factors