Multiple sevoflurane exposures in infant monkeys do not impact the mother-infant bond

Abstract

Exposure to general anesthesia during the postnatal period is associated with death of brain cells as well as long-term impairments in cognitive and emotional behavior in animal models. These models are critical for investigating mechanisms of pediatric anesthetic neurotoxicity as well as for testing potential strategies for preventing or mitigating this toxicity. Control conditions for anesthesia exposure involve separation of conscious infants from their mothers for variable periods of time, which could have its own effect on subsequent behavior because of stress to the mother and/or infant as a consequence of separation.We are conducting a long-term study of infant rhesus monkeys exposed three times for 4h each to sevoflurane anesthesia during the first six postnatal weeks, with a comparison condition of control infant monkeys that undergo brief maternal separations on the same schedule, to equate the period of time each infant is conscious and separated from its mother. Because mothers are separated from their infants longer for infants in the anesthesia condition, this could modify maternal behavior toward the infant, which may influence subsequent socioemotional behavior in the infants. In this study, we analyzed maternal behavior immediately after the first post-anesthesia (or control) reunion, as well as during reintroduction of the mother-infant pair to the larger social group 24hpost-anesthesia or control separation, and found no differences between the conditions with mothers spending most of their time in contact with infants in all conditions analyzed. This indicates that the different durations of maternal separation in this study design do not impact the mother-infant bond, strengthening conclusions that subsequent differences in behavior between monkeys exposed to anesthesia compared to controls are a consequence of anesthesia exposure and not differential maternal behavior in the two conditions.