Genetic Activity in the Brain
Through examination of thousands of genes in the frontal cortex in the autistic brain we have learned there is a specific set of genes that appear to operate abnormally during prenatal development in autism.
These genes are supposed to check the number and quality of brain cells that are made during prenatal life, in the second trimester. Abnormal activity in these genes may cause an excess number of abnormal brain cells to be made and this may be the start of developmental problems in autism.
We also found genes that may cause certain brain regions to organize brain cells into incorrect brain cell assemblies, which would also cause abnormal brain functioning. From these new studies we expect to identify genetic and molecular systems that can be changed to normalize the course of neural development and help babies at risk for autism achieve a more normal outcome.
Finding Autism Genes
To test for genes related to autism we first take a sample of frozen cortex and extract its RNA. Each gene is a sequence of DNA; DNA makes RNA. The functional activity level of a gene is signaled by how much RNA it makes: on average, more active genes make more RNA and less active genes make less RNA.
Each RNA is the message a gene sends to the cell to make molecules that are the building blocks for synapses, axons, dendrites, chemical neurotranmitters and so much more. Gene activity can be inhibited or turned up and these changes are reflected in the amount of RNA from that gene.
We then use microarray technology to quantify RNA levels of every gene followed by advanced
bioinformatics analyses to detect abnormal patterns of RNA levels. These patterns help tell us which gene functions are affected in autism.