title: The effects of maternal isolation and light and feeding cycles on the growth of rat pups.
abstract: Rat pups were implanted with intragastric catheters and reared in isolation from their dams and siblings from 3 to 18 days postnatally. They were kept in 12:12 LD or DL, constant light, or constant darkness and were fed with one of three feeding schedules: equal amounts of food delivered during the light and dark periods, 65.3% of the food delivered during the light period, or 65.3% of the food delivered during the dark period. At 18 days postnatally the body, spleen, and kidney weights of all isolated pups did not differ from those of their mother-reared littermates. The isolated pups had smaller cerebellums and forebrains and heavier livers than mother-reared pups. Heavier body and spleen weights and smaller livers were observed in pups with cyclic feeding. Heavier body and forebrain weights were associated with a predominantly diurnal feeding schedule--the schedule which most closely approximated the natural nursing rhythm. Isolated pups opened their eyes sooner than mother-reared littermates. These results suggest that interactions between feeding and light cycles may influence growth and development.
mesh_terms: D000818:Animals; D001835:Body Weight; D001921:Brain / Q000254:growth & development; D002531:Cerebellum / Q000254:growth & development; D005247:Feeding Behavior / Q000502:physiology*; D006128:Growth; D006813:Humidity; D008027:Light; D008099:Liver / Q000254:growth & development; D008426:Maternal Deprivation; D009929:Organ Size; D010507:Periodicity; D051381:Rats; D011919:Rats, Inbred Strains; D012934:Social Isolation; D013154:Spleen / Q000254:growth & development