OFFSPRING-INDUCED NURTURANCE - ANIMAL-HUMAN PARALLELS

Offspring provide mothers with stimuli that impel their own nurturance . In rats, distal sensory stimuli from pups-sight, sound, odor-contrib ute to contact-seeking, whereas tactile stimuli from pups to dam's sno ut and ventrum elicit essential maternal behavioral reflexes involved in retrieval, licking, and the quiescent, upright nursing posture (kyp hosis). Brain sites involved with maternal behavior-assessed by lesion s, immunocytochemical visualization of gene activity, and neurophysiol ogical mapping-include the midbrain central gray, menial preoptic nucl eus, limbic system, and somatosensory cortex; these may change with ex perience. Human mothers inadvertantly learn to identify their own baby rapidly after birth and can do so via a single sensory modality. Subs equent maternal responsiveness and gratification are impair ed by inap propriate, insufficient, or nonreciprocal interactions such as occurs when the baby cries excessively, is blind, deaf, or autistic. Thus, ma ternal behavior characterized by elicited responses and emotional reac tions to stimuli from offspring may be evolutionarily conserved. (C) 1 997 John Wiley & Sons, Inc.