Development of body temperature rhythms in blinded and intact rats nursed under a light-dark cycle or in constant darkness

摘要

The development of body temperature (BT) rhythm was analyzed in blinded and intact rats to investigate the ontogeny of BT rhythm. BT rhythm was determined from the rectal temperature measured at 2 h intervals over a period of 26 h using a mercury thermometer. Adult-like BT rhythm pattern developed around the 28-30th day after birth under the light-dark (LD) cycle. The extrapolated peak time (acrophase) of BT rhythm in blinded pups at the day of weaning, both those nursed under the LD cycle and those reared in constant darkness, corresponded to the mother's non-active period. These results indicate that pup's BT rhythm is partly modified during the nursing period.