Effects of maternal deprivation and the duration of reunion time on rat pup ultrasonic vocalization responses to isolation: possible implications for human infant studies.
In a paradigm that may serve as a translational model for maternal separation experiences of human infants in neonatal intensive care units, we examined how the duration of reunion with the dam influenced the phenomenon of maternal potentiation of ultrasonic vocalizations, in which isolated rat pups increase rates of vocalization following brief interactions with dams. We report that maternal potentiation in 12-13 day-old rats did not occur after reunions with their anesthetized dam that lasted longer than 15-min. However, after 18 hr maternal separation, isolated pups given reunions with their anesthetized dam increased vocalization rate even with reunions as long as 3 hr. Using a split-cage apparatus that prevented physical contact, the impact of 18 hr separations on maternal potentiation was partially offset by experiencing olfactory and/or auditory stimuli of the mother. These results suggest that maintaining partial maternal sensory exposure during prolonged maternal separation can reduce responses elicited by subsequent maternal separation.
Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, 10032, NY; Departments of Psychiatry, Columbia University College of Physicians and Surgeons, New York, 10032, NY.
Harry N
HN
Shair
Deborah D
DD
Rupert
Lauren M
LM
Rosko
Myron A
MA
Hofer
Michael M
MM
Myers
Martha G
MG
Welch
D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D005260:Female; D008297:Male; D008426:Maternal Deprivation; D011247:Pregnancy; D051381:Rats; D020318:Rats, Long-Evans; D013997:Time Factors; D014465:Ultrasonics; D014828:Vocalization, Animal
contact quieting; isolation; maternal odor; maternal potentiation; maternal reunion; maternal separation; neonatal intensive care; olfaction; ultrasonic vocalization