The BRAIN Initiative, the 9-year multi-billion dollar US neuroscientific effort, today announced its most ambitious challenge yet: to compile the world’s most comprehensive map of human brain cells. Scientists say the BRAIN Initiative Cell Atlas Network (BICAN), funded with $500 million over 5 years, will help them understand how the human brain works and how diseases affect it. BICAN “will transform the way we do neuroscience research for generations to come,” says BRAIN Initiative director John Ngai of the National Institutes of Health (NIH).
BRAIN, or Brain Research Through Advancing Innovative Neurotechnologies, was launched by then-President Barack Obama in 2013. He started with a focus on tools, then developed a program called the BRAIN Initiative Cell Census Network, which resulted in a series of documents in 2021. The studies combined data on the genetic characteristics, shapes, locations, and electrical activity of millions of cells to identify more than 100 cell types in the primary motor cortex, which coordinates movement, in mice, marmosets, and humans. Hundreds of researchers involved in the network are now completing a cell census for the rest of the mouse brain. It is expected to become a widely used and free resource for the neuroscience community.
Now, BICAN will characterize and map neuronal and non-neuronal cells throughout the human brain, which has 200 billion cells and is 1,000 times larger than a mouse brain. “He’s using similar approaches but expanding,” says Hongkui Zeng, director of the Allen Institute for Brain Science, which won a third of BICAN’s funding. Zeng says the results of the effort will serve as a benchmark, a kind of Human Genome Project for neuroscience.
Other groups will aggregate data from human brains across a variety of ancestors and ages, including fetal development. “We will try to cover the breadth of human development and aging,” says Joseph Ecker of the Salk Institute for Biological Studies, who leads the BICAN studies of epigenetics, the study of hereditary changes that are transmitted without changes in DNA. Ngai expects BICAN to study several hundred human brains overall, though the researchers are just beginning to work out the details. “Sampling and coverage will be a big topic of discussion,” says Ngai.
An additional $36 million announced over 3 years today will fund the Armamentarium BRAIN, which will develop viral vectors and lipid nanoparticles that will harbor and genetically modify specific types of brain cells. These tools will help scientists study cell function and develop treatments for diseases.
A third project called BRAIN CONNECTS focuses on tracing wiring diagrams in mammalian brains; early next year it will get $30 million in grants that will last up to 5 years. In total, NIH has spent $2.5 billion so far on BRAIN, a figure they hope to reach $5.2 billion by the end of 2026.