| aily rhythms are ubiquitous in terrestrial animals. Persistence of rhythms in constant conditions, with periods around 24 hours, hence "circadian", shows many of these to be endogenous, including the rhythm in body temperature ;Six adult male squirrel monkeys (Saimiri sciureus) were studied for periods up up to 7 days. Body temperature, heat production (HP), heat loss (HL), thermal conductance activity, feeding and drinking rhythms were measured. Entraining light-dark cycles (LD 12:12) and masking light-dark cycles (LD 2:2) were used, as well as constant light (LL). Standard ;Heat production and HL demonstrated circadian rhythms phase-coupled with both the entrained and free-running ;Light masking, known to alter ;The organization of free-running thermoregulatory rhythms was largely unchanged by a cold... |
