A research team found that when baby rhesus monkeys endured high rates of maternal rejection and mild abuse in their first month of life, their brains often produced less serotonin, a chemical that transmits impulses in the brain. Low levels of serotonin are associated with anxiety and depression and impulsive aggression in both humans and monkeys.
Abused females who became abusive mothers in adulthood had lower serotonin in their brains than abused females who did not become abusive parents, the research showed.
Because the biological make up of humans and monkeys is quite similar, the findings from the monkey research could be valuable in understanding human child abuse, said Dario Maestripieri, Associate Professor in Comparative Human Development at the University of Chicago.
"This research could have important implications for humans because we do not fully understand why some abused children become abusive parents and others don't," Maestripieri said. The research suggests that treatments with drugs that increase brain serotonin early in an abused child's life could reduce the likelihood that the child will grow up to become abusive, Maestripieri said.
Maestripieri is lead author of a paper reporting the research, "Early Maternal Rejection Affects the Development of Monoaminergic Systems and Adult Abusive Parenting in Rhesus Macaques" published in the current issue of Behavioral Neuroscience.
The study is the first to show that naturally occurring individual variation in maternal behavior in monkeys can affect the brain development of the offspring, and the first to show a link between serotonin and infant abuse in primates. Other research using rats as animal models has shown that serotonin production is influenced by a mother's treatment of he
Contact: William Harms
University of Chicago