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Prenatal drug exposure disrupts brain connectivity in infants, potentially affecting arousal regulation

Prenatal drug exposure disrupts connectivity within regions of the brain related to arousal regulation and cocaine specifically affected the amygdala frontal network, according to study findings in The Journal of Neuroscience.

“Prenatal drug exposure is a significant public health concern. Particularly, prenatal cocaine exposure has attracted considerable attention given its well documented influence on developmental and behavioral outcomes. However, neural correlates of [prenatal drug exposure] in humans have been scarcely studied and the results are inconsistent,” study researcher Andrew P. Salzwedel, PhD, of the University of North Carolina at Chapel Hill, and colleagues wrote.

Researchers conducted resting-state functional magnetic resonance imaging (rsfMRI) scans among 45 infants with prenatal cocaine exposure, 43 infants exposed to some combination of non-cocaine drugs in utero and 64 infants not exposed to any drugs. Functional connectivity analyses were based on the amygdala and insula regions because these regions experience the earliest prenatal structural and functional growth and have been shown to experience functional connectivity disruptions among cocaine-dependent adults.

Infants exposed to cocaine or other drugs (including marijuana, alcohol, nicotine and antidepressants) were born approximately 7 days earlier and weighed 14 ounces less than infants exposed to non-cocaine drugs or no drugs at all.

Wei Gao

Mothers of children with prenatal cocaine exposure had lower education and higher depression levels compared with mothers of children in the other two groups.

Children exposed to any kind of drug exhibited abnormalities in the functional organization of the brain, according to analysis. Children with prenatal cocaine exposure had additional abnormalities that the other group of children exposed to drugs did not.

Prenatal cocaine exposure was associated with a reduced anti-correlation between the amygdala and part of the prefrontal cortex, which suggests a potential failure or risk for failure in the suppression of amygdala responses from the prefrontal cortex.

“To our knowledge, this study is the first to show that maternal drug use during pregnancy alters the brain’s functional organization in newborns,” study researcher Wei Gao, PhD, assistant professor of radiology at the University of North Carolina School of Medicine, said in a press release.

The study findings, if expanded on in future research, could aid in developing new strategies for early risk identification and intervention, study researcher Karen M. Grewen, PhD, noted in the release. – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.