Study defines differences among brain neurons that coincide with psychiatric conditions
Previous studies of key brain cells have found little variability in a common cell process that involves how genetic information is read and acted on.
The process, called epigenetics, involves chemical or structural “tweaks” to gene activity that don’t affect the underlying genetic code itself, but do affect when and how a gene becomes available to be read for its protein-encoding instructions. When epigenetic changes strike at the wrong time or place, the process turns genes on or off at the wrong time and place, too.
In a new study focusing on four regions of normal human brain tissue, Johns Hopkins scientists have found about 13,000 regions of epigenetic differences between neurons in different brain regions that vary by at least 10 percent. Using whole genome sequencing and computational statistical tools, they also found that the location of those epigenetic changes—covering about 12 million bases in the genome—co-locate with the genetic signal contributing to addictive behavior, schizophrenia, and neuroses such as bipolar disorder.
“We believe we have figured out what parts of the neuronal genome are epigenetically different among these four brain regions,” says Andrew Feinberg, the Bloomberg Distinguished Professor of Medicine, Oncology, and Molecular Biology and Genetics. “And these areas are enriched with inherited genetic variants linked to certain psychiatric conditions.”