Key Genes Involved in Encoding Memories Identified

A team of researchers from the University of Texas have identified key genes involved in brain waves that are pivotal for encoding memories. The findings were published in Nature Neuroscience. 

"We know that cells are involved in learning fire in groups and form new connections because of the influence of these oscillations. But how genes regulate this process in people is completely unknown," says lead researcher Bradley Lega. 

While recording the electrical activity in the brains of 16 volunteers, the researchers had them do "free recall" tasks that involved reading a list of 12 words, doing a short math problem to distract them, and then recalling as many words as possible. As these patients were memorizing the word lists, their brain waves were recorded, creating a dataset that differed slightly from person to person. The volunteers were epileptic patients scheduled to have surgery to remove the damaged parts of their brains that spark seizures. After their surgery, the brain tissue was sent for processing to assess genetic activity.

The team then performed whole RNA sequencing in the temporal lobe samples that included all the brain's cell types. Using statistical techniques that linked this activity to the patients' neural oscillations during the free recall task, the researchers identified 300 genes that appeared to play a part in oscillatory activity. The researchers narrowed this number to a dozen hub genes that appeared to control separate gene networks. Finally, the researchers used ATAC-seq, and honed in on SMAD3, a gene that appears to serve as a master regulator to control activity of many of the hub genes and the genes they control in return. "This gives us an entry point," said collaborator Genevieve Konopka, "It's something we can focus on to learn more about the underpinnings of human memory."