The Beginning of a New Era in Brain Research: The Publication of the Most Detailed Map of the Brain

An international group of researchers has just released the most detailed map of the human brain ever made. This momentous accomplishment provides crucial groundwork for studying and treating brain-related illnesses and provides priceless insights into what makes us uniquely human.

Tomasz Nowakowski, a neuroscientist at the University of California, San Francisco and co-author of 21 papers in scholarly journals, said, "It's a dream that has been around for more than a century. This is like building a map of the universe. More than 250 academics from 45 institutions across three continents worked together for a decade on this ground-breaking study that cost the federal government over $500 million.

Human brain tissue was used in the studies, either fresh from surgeries or preserved from postmortem donations. Thin sections of the living tissue were used to examine the properties of individual cells, while postmortem samples revealed information about the molecular composition of the brain's many specialized cell types. Over 3,000 distinct brain cell types were identified and their growth from infancy to adulthood was thoroughly tracked by the scientists.

Creating a detailed map of the healthy human brain is the primary focus of this massive project. To better understand what goes wrong and where treatments might be targeted, this map will serve as a reference point for researchers examining a wide range of brain-related ailments.

We had a map of the country, but the cities and streets were all blurry, and that's how it was with our understanding of the human brain until recently. Because of this murkiness, deciphering the mind's intricate workings was next to impossible. Similarities between the Human Genome Project, which released our genetic code in 2003 after more than a decade of labor and $2.7 billion in funding from the National Institutes of Health, and the brain-mapping program have been noted by researchers in the field of neuroscience. This ground-breaking feat paved the way for future developments in the biotech industry, such as consumer-facing genetic testing, diagnostic improvements for cancer and rare diseases, and forensic applications. As a result, groundbreaking initiatives such as the brain-mapping work detailed in these recent studies become possible.

Some scientists believe that we have a better understanding of the solar system than of the complex neural networks in our brains, which they argue determine who we are and how we can do things like create music that moves us emotionally or perform difficult gymnastic feats. Alzheimer's disease, epilepsy, schizophrenia, autism, and depression are all brain-related illnesses, but the development of effective therapeutics has been hampered by the fact that much of what we know about brain anatomy and function has been gleaned from studying the brains of other animals. Because we don't fully understand what makes the human brain different from the brains of mice and nonhuman primates, promising medicines sometimes fail in animal testing.

These new studies' ability to capture individual variances in human brains is groundbreaking. It's important to remember that the ratio of cells in critical brain regions is what truly sets humans apart from other mammals, not the sorts of cells themselves. For example, the findings reveal that glial cells, commonly referred to as "support" cells, in the human brain suffer more changes in gene expression than neurons, particularly when compared to the brains of nonhuman primates. This finding suggests that the substantial differences in our cognitive capacities as compared to other species may have their roots in quite tiny changes. Synapses are the building blocks of the brain's information processing and learning, and they are shaped in large part by glial cells.

Furthermore, these investigations have revealed cell-level differences between different human brains. This fascinating discovery not only explains what it is that makes our brains human, but also highlights the ways in which each of us is special. The next step in the research process will involve characterizing the connections between brain cells rather than just researching the cells themselves. Deputy director of the National Institutes of Health's BRAIN Initiative Andrea C. Beckel-Mitchener views this partnership as "unprecedented in neuroscience." There has never been a more promising time to study the brain, with new avenues opening up that could lead to revolutionary new treatments for neurological disorders.

Postmortem human brain samples at the Allen Institute for Brain Science. PHOTO: ERIK DINNEL/ALLEN INSTITUTE