Tue March 12, 2013
Dr. Rebecca Knickmeyer, University of North Carolina Chapel Hill – Infant Brains and Adult Disorders
In today’s Academic Minute, Dr. Rebecca Knickmeyer of the University of North Carolina Chapel Hill explains how an infant’s brain can display signs of future neurological disorders.
Rebecca Knickmeyer is an assistant professor of psychiatry at the University of North Carolina at Chapel Hill School of Medicine. Her work is focused on understanding the mechanisms that create differential vulnerability to, and expression of, neurodevelopmental disorders in each sex, with a particular focus on hormonal and genetic factors. Her current project utilizes MRI to explore the sexual differentiation of the brain in human children and in non-human primates. She earned her Ph.D. at the University of Cambridge.
Dr. Rebecca Knickmeyer – Infant Brains and Adult Disorders
Why do some people develop psychiatric and neurological illnesses while others do not? Many scientists believe that individual differences in our genes impact our risk for these illnesses by changing the structure or function of our brains, but when exactly do these genes exert their effects? Is it immediately before an individual develops symptoms or are they present much earlier, perhaps even from birth?
To address this question we studied 272 newborn babies using magnetic resonance imaging or MRI. The DNA of each was tested for 10 common variants in 7 genes that have been linked to brain structure in adults. These genes have also been implicated in conditions such as schizophrenia, bipolar disorder, autism, and Alzheimer’s disease. For some variants, the brain changes we found in infants looked strikingly similar to those reported in adults. For example, newborns carrying a variant known as ApoE4 which is associated with increased risk for Alzheimer’s disease had reduced volumes in the medial temporal lobe, a brain area with an important role in memory. Volume losses show up in similar areas in adults who carry this variant and these brain regions are typically altered in individuals with Alzheimer’s.
While these results are fascinating, it is important to remember that genes aren’t destiny. Multiple factors influence how the brain develops, but studying newborns allows us to look at genetic effects before many of those factors come into play. Our findings highlight how important the prenatal period may be for outcomes many years in the future and could stimulate new research focused on preventing onset of illness through very early intervention in at-risk individuals.