Problems during the brain's development can result in a variety of medical difficulties, including autism spectrum disorders. A thorough understanding of neural development is therefore crucial to uncovering the causes of autism.
Nicholas Gaiano, of the Johns Hopkins University School of Medicine, and his colleagues are examining the role of an autism-associated gene expressed during development of the neocortex — an area of the brain that controls the cognitive functions that are affected in people with the disorder.
The gene, CNTNAP2, is thought to play a causal role in autism when mutated, and some common variants of the gene confer a greater risk of the disorder. The researchers recently found that CNTNAP2 is expressed differently in two populations of cells central to neocortex development: neural stem cells and their successors, intermediate neural progenitor cells. This finding led the scientists to hypothesize that the gene plays a role in regulating neural stem cells, and that mutations in the gene can lead to autism by derailing the cells' growth and differentiation.
To elucidate the gene's role, Gaiano's team is using several molecular methods. They have examined the expression of CNTNAP2 in the neocortex of developing mice, and have found it to be expressed in the germinal zone, both embryonically and during early postnatal life. In addition, they are examining the effects of both over-expressing and under-expressing the gene during neocortical development. In vitro studies of the effect of CNTNAP2 on neural cell development are now being performed.
The researchers believe that this work will uncover some of the molecular mechanisms at work in normal brain development, and explore how malfunctions in these processes can lead to autism.