An intrinsic source of behavioral regulation that influences discrete responses to cues important for the initiation of suckling

The present experiment investigated the relationship between motor activity and oral grasping of an artificial nipple in newborn rats. Pups orally gra sped the artificial nipple, and they performed more and longer oral grasps in the latter portion of the nipple presentation. Motor activity was cyclic al, and this cyclicity was evident before and during presentation of the ar tificial nipple. The onset of an oral grasp response was preceded by a peri od of relatively low motor activity, and the termination of a grasp was fol lowed by relatively high motor activity. The newborn rat pup's intrinsic os cillations in motor activity may regulate the expression of discrete respon ses to cues important for the initiation of suckling.