Ultrasonic Control of Maternal Behavior: Developmental Implications

Infant rodents of many species emit high frequency vocalizationswhen aroused. These signals, when detected by adult femalesof the same species, elicit increased care-giving. The behaviorof the dam towards her offspring influences the developmentof arousal mechanisms of the offspring and appears to alterturnover of brain dopamine. These effects are quite pervasivesince altered maternal care induced by ultrasonic vocalizationsfrom an initial litter is observable in the behavior of thedam towards a subsequent litter; similar alterations in thedevelopment of arousal mechanisms and brain dopamine turnoverare observable in the subsequent litters; and the effects ofthis altered caregiving during the first three weeks of developmentare observable in laboratory rats (Rattus norgevicus) at oneand two years of age.