Obama wants to map the human brain - Why?

An image of the human brain. Photography: Sebastian Kaulitzki / Alamy

It's enough to make neuroscientists scream – for joy, or exasperation. Amidst criticism of the European Commission's decision to award €1bn to the Human Brain Project came news that the US was planning its own version. In February, the New York Times announced that a project called the Brain Activity Map (BAM) was in the works. Today, President Obama confirmed that the project will go ahead under the new name Brain Research through Advancing Innovative Neurotechnologies (BRAIN). But details are scarce, including how much the project will cost, its goals, and plans for meeting them.

This isn't a moment to celebrate. It's a missed opportunity.

Investing in neuroscience is a great idea, but this is not a general boost in funding for neuroscience research. This is concentrating funds on one project, putting many eggs in one basket. Early estimates indicate BRAIN could receive as much $3bn over 10 years. Today's announcement revealed there will be an initial investment of $100m in 2014, after which additional budgeting will be decided.

All that money for a project that has yet to come up with "a plan, a time frame, specific goals". Yet, there are laboratories all over the country who have very well-defined projects and are in need of $1 to $2m. Imagine if President Obama instead announced $1m for 100 neuroscience projects every year for the next 10 years. The country could become a neuroscience hub, able to recruit talented researchers from all over, boost the economy, and reestablish America's sliding position as a world leader in science and technology. Sadly, US leaders think they need a 'Big Science' project to compete.

What does the project aim to do? In June of 2012, scientists published an article in Neuron first proposing BAM/BRAIN:

Understanding how the brain works is arguably one of the greatest scientific challenges of our time....A fundamental underlying limitation is our ignorance of the brain's microcircuitry.

No argument there. We are still in the infant stages of understanding how neurons throughout the brain are connected, how these connections give rise to behaviors, or how connections change. Understanding brain microcircuitry is a must for neuroscience. But how do we do that? We propose to record every action potential from every neuron

Here's where the problems start. In simple model systems, like the fruitfly, the brain contains more than 100,000 neurons. Recent estimates put the number of neurons in the human brain at around 86bn, located at various depths. Even if we could access all neurons, which we can't with current technology, how will we record the activity of every one? The authors propose imaging the activity of neurons using voltage sensors – indicators that light up when the electrical potential of a cell changes. But a recent review points out:

"Voltage imaging methods suffer from poor signal to noise and secondary side effects, and they fall short of providing single-cell resolution."

Should we be developing this technology? Absolutely. Should we bank on the idea that even substantial advances could permit "imaging every spike from every neuron"? Absolutely not. The authors also discuss the use of electrical recording probes: "There are technical hurdles to be surmounted, but when the technology is perfected, recording from many thousands of neurons is conceivable."

Many thousands of neurons is a far cry from 86bn. And even if their activity is recorded, how will it be separated and analyzed? Researchers working with only hundreds of recording sites face significant challenges in separating signals to determine which spikes come from which neurons.

Finally, the authors propose a technique that has received the largest attention:

"DNA molecules could be synthesized to record patterns...of spikes in each cell, encoded as calcium-induced errors, serving as a 'ticker-tape' record of the activity of the neuron."

Sounds like a dream. And that's exactly what it currently is. Last year, researchers published a paper in PLoS ONE showing how cation concentrations could be monitored using DNA polymerases. But that work was done in cultured bacteria, and has yet to be tested in cultured neurons, let alone in vivo. Yes, we should invest in this technology, but it should not be a cornerstone of a multi-million dollar project...yet.

In recent months, researchers published articles in Science and ACS Nano emphasizing that a goal of the project will be to develop new technologies for studying the brain. President Obama is also concentrated on technology-building, as indicated by the project's new name and continued reference to potential economic returns as seen with the Human Genome Project. But BRAIN is not the Humane Genome Project.

HGP had defined goals; researchers knew where they were going and what an end result should look like. BRAIN researchers have yet to figure this out. What will a complete map of the brain look like? How will we know when it is complete? How will the dynamic nature of the brain be accounted for? Will recording the activity of all neurons in the brain produce understanding of behaviors or diseases? Neuroscientist Donald Stein has said, "the technology ought to follow the concepts rather than the other way around."

I couldn't agree more.