Maternal contributions to sensory experience in the fetal and newborn rat (Rattus norvegicus).

Using videographic analyses, we identified and quantified maternal contributions to the sensory environment of the perinatal rat (Rattus norvegicus) by analyzing, from the offspring's perspective, the dam's activities during gestation, labor, and delivery. Our observations indicate that pregnant females remain highly active during the final week of gestation, as compared with nonpregnant control animals. Exploratory movements, feeding, drinking, self-grooming, and other activities of the rat dam pitch, turn, accelerate, and expose fetuses to mechanical pressures. During parturition uterine contractions and maternal licking and handling provide vigorous tactile and vestibular stimuli to pups. Newly born pups are exposed to intense thermal stimulation, cooling rapidly to the temperature of the postnatal environment. Our results suggest that fetal and newborn rats are exposed during development to a broad range of maternally produced stimuli.