Autism affects ~1% of the population and can have a major impact on the lives of patients and their friends and families. Altered sensory perception is a hallmark of Autism and the relay of information from sense organs through the thalamus and onto the cerebral cortex via the thalamocortical axon tract is a key step in processing sensory input. Recent research has implicated developmental defects in the thalamus and its connections to the cerebral cortex in Autism patients (Green et al 2017).
Copy number variation (CNV) of the 16p11.2 locus on chromosome 16 is one of the most common single genetic causes of Autism [1-4] accunting for ~1% of cases and giving strong motivation for understanding the underlying mechanism. The 16p11.2 CNV is associated with infant brain overgrowth (macrocephaly in microdeletion patients) or undergrowth (microcephaly in microduplication patients), suggesting mechanisms acting during pre-natal brain development (Packer et al., 2016). The 16p11.2 locus includes 29 genes many of which are strongly expressed in the developing human brain (Morson et al., 2019) supporting the hypothesis that brain development is disrupted in 16p11.2 patients and that this underpins the subsequent development of ASD symptoms. This provides strong motivation for investigating neurodevelopmental defects caused by the 16p11.2 CNV.
This project will initially investigate the impact of the 16p11.2 microdeletion on the development of the thalamus and its connections to the cerebral cortex in a rat 16p11.2 microdeletion model. Other approaches to tackle this question may be employed as the project develops.
This project will provide training in molecular biology, histology, comparative anatomy, ex vivo tissue culture, imaging, and data analysis.
Green SA, Hernandez L, Bookheimer SY, Dapretto M. (2017). Reduced modulation of thalamocortical connectivity during exposure to sensory stimuli in ASD. Autism Research 10. 801-809.
Morson S, Yang Y, Price DJ, Pratt T (2019) Expression of genes in the 16p11.2 locus during human fetal cortical neurogenesis. bioRxiv 633461; doi: https://doi.org/10.1101/63346
Packer A. (2016) Neocortical neurogenesis and the etiology of autism spectrum disorder. Neurosci Biobehav 64:185-95.