The Brain Initiative, funded by the National Institutes of Health (NIH), has so far identified 3,000 different brain cell types. Many scientists have compared the initiative to the human genome project. One of them says the comparison is apt when you look at the scope of the projects and the collaboration involved.
“That is the heart and soul of the soul of the brain initiative,” said Bing Ren, professor of molecular biology at UC San Diego. “It is designed to bring scientists doing very different work together to solve one big problem: What are brains made of and how (do) they function.”
Ren said the genome project and the Brain Initiative are also linked in a way that explains the epigenetic research he does for the initiative. He said the work of those 3,000 brain cells, in fact their very identity, depends a lot on how their genes are activated.
“Tiny changes in the sequence of our DNA can make someone more prone to psychiatric disease. Such as depression, schizophrenia or addiction for example,” Ren said.
The Brain Initiative has just published 21 papers in the journal Science, revealing what some call a preliminary “map” of the human brain. San Diego scientists have played a prominent role in the project.
Working as a team, they are looking at the way genes within the brain cells are switched on and off. That work is divided between UCSD and another place, right across the street.
The Salk Institute has studied human and animal brains for many years. In fact, last year Salk received $77 million from the NIH, the biggest grant in its history, to work on the human Brain Initiative.
Margarita Behrens, a neuroscientist at Salk, said calling the research published last month a “map” of the brain is a bit absurd because they’re not there yet. Though that is the goal, the research has a long way to go.
So far, the work done in San Diego shows how genes can affect brain cells, for good or bad. Behrens said a key part of this is identifying the kinds of cells that can be compromised by known genetic variants.
“The genetic variants that give vulnerability to a disease like Alzheimers seem to be more important in one cell type and not the others,” Behrens said.
Researchers I spoke with are careful to describe their findings in modest terms. For example, Behrens said they can’t yet say genetic effects on cells cause psychiatric disease.
Ren still said the beginnings of the brain initiative represent a good step forward.
“Our study has pointed out the type of cells, the type of genes and the type of molecular pathways that are likely involved. It’s a candidate list. The next step is to further narrow down that list and pinpoint the most critical genes,” he said.
So far, all of the research done for the brain initiative has relied on samples of three brains from three male donors. Given the complexity of the human brain, Behrens said the initiative will need a lot more samples in the future.
“With a human brain, each brain is different, and the variability is very high. And to be able to find our core things, in those ones that are variable, you need a lot of brains,” she said. “And that is why I say we need to go big.”
Researchers at the Salk Institute have done extensive studies of the mouse brain, and Behrens said we do have a good map of that. But a mouse brain is made up of 80 million neurons. The human brain has 80 billion neurons.
