Fetal Alcohol Syndrome (FASD): Prenatal exposure to alcohol disrupts brain circuitry

Prenatal exposure to alcohol severely disrupts major features of brain development that potentially lead to increased anxiety and poor motor function, conditions typical in humans with Fetal Alcohol Spectrum Disorders (FASD), according to neuroscientists at the University of California, Riverside.

In a groundbreaking study, the UC Riverside team discovered that prenatal exposure to alcohol significantly altered the expression of genes and the development of a network of connections in the neo-cortex—the part of the brain responsible for high-level thought and cognition, vision, hearing, touch, balance, motor skills, language, and emotion—in a mouse model of FASD.

Prenatal exposure caused wrong areas of the brain to be connected with each other, the researchers found.

These findings contradict the recently popular belief that consuming alcohol during pregnancy does no harm.

"If you consume alcohol when you are pregnant you can disrupt the development of your baby's brain," said Kelly Huffman, assistant professor of psychology at UC Riverside and lead author of the study that appears in the Nov. 27 issue of The Journal of Neuroscience, the official, peer-reviewed publication of the Society of Neuroscience.

Study co-authors are UCR Ph.D. students Hani El Shawa and Charles Abbott.

"This research helps us understand how substances like alcohol impact brain development and change behavior," Huffman explained.

"It also shows how prenatal alcohol exposure generates dramatic change in the brain that leads to changes in behaviour.

Although this study uses a moderate- to high-dose model, others have shown that even small doses alter development of key receptors in the brain."

Researchers have long known that ethanol exposure from a mother's consumption of alcohol impacts brain and cognitive development in the child, but had not previously demonstrated a connection between that exposure and disruption of neural networks that potentially leads to changes in behaviour.

Huffman's team found dramatic changes in intra-neocortical connections between the frontal, somato-sensory and visual cortex in mice born to mothers who consumed ethanol during pregnancy.

The changes were especially severe in the frontal cortex, which regulates motor skill learning, decision-making, planning, judgment, attention, risk-taking, executive function and sociality.