Russell Poldrack scanned his brain to create the most detailed map of brain connectivity ever. In the process, he and his colleagues revealed strong correlations between brain function and gene expression, and how the brain reorganizes itself when running low on caffeine.
Every Tuesday and Thursday morning for a year and a half, Russell Poldrack started off his day by climbing into an MRI machine and scanning his brain for 10 minutes. The self-experimentation has made the Stanford psychologist's brain the most studied in the world.
In any action that a person undertakes, many different regions of the brain communicate with each other, serving as a sort of check-and-balance system to make sure that the correct actions are taken to deal with the situation at hand. "I would get in the MRI and basically close my eyes and zone out while it took a picture of my brain every second for 10 minutes," he said. "Once we had that data, we could get ideas of which regions of my brain are talking to each other by how correlated they are over time. This tells us how much connectivity there is within each network."
Poldrack's connectivity was surprisingly consistent, but it did show some changes over the course of the 18 months which have never before been observed. While this result raises many new questions, the robust consistency showed that the long-term approach has promise for revealing differences between healthy brains and those of patients with neurological disorders that might suffer from disrupted connectivity, such as schizophrenia or bipolar disorder.
On Tuesdays, Poldrack fasted and gave a blood sample after his scanning session. The RNA from his white blood cells was sequenced to determine his gene expression, which was then compared to his brain function.
The researchers found a strong correlation between brain activity and changes in the expression of many different families of genes. They also found that expression of genes related to inflammation and immune response matched Poldrack's psoriasis flare-ups. Because the data set is so massive, there are still many questions to ask, which is why Poldrack is making all of the data publicly available.
On Tuesdays, when he hadn't drunk his morning joe before the scan, the connectivity within his brain looked very different from his caffeinated brain.
"That was totally unexpected, but it shows that being caffeinated radically changes the connectivity of your brain," Poldrack said. "We don't really know if it's better or worse, but it's interesting that these are relatively low-level areas. It may well be that I'm more fatigued on those days, and that drives the brain into this state that's focused on integrating those basic processes more."
Read the full article from Stanford University.