Copy number variation (CNV) of the 16p11.2 region is associated with numerous developmental problems, including an increased risk for autism. Little is known about how the function of the cortex differs between individuals with 16p11.2 deletions and duplications, and between those who have autism and those who do not. Charles Nelson and his colleagues set out to investigate these knowledge gaps in a sample of children with 16p11.2 CNVs using electrophysiological methods to assess cortical processing.
The research team recorded the electrical response of the brain using electroencephalography (EEG) while both typically developing children and those with 16p11.2 deletions or duplications participated in passive watching or listening tasks. One interesting finding that emerged from this study is that the amplitude of the visual cortex’s response to simple visual stimuli (i.e., checkerboard patterns) appears to be enhanced in individuals with deletions and diminished in those with duplications.
One possibility is that one or more genes located in the 16p11.2 region regulates the excitability of the cortex, potentially by modulating synaptic strength and/or connectivity. However, future studies are needed to address this. Recording-evoked potentials during simple passive sensory paradigms offer a promising noninvasive method to assay cortical function across a broad range of ages and levels of functioning — ideal for this particular population. In addition, this method is currently being used in animal models of 16p11.2 CNVs, providing a platform for informative translational studies.