Atlas of Human Brain Development Released

Pauline Anderson

April 11, 2014

Think of it as Google Earth for the developing brain. Researchers have created an atlas that illustrates the activity of thousands of genes during human brain development that should shed new light on brain-based disorders, such as autism.

The comprehensive, anatomically correct, and very-high-resolution BrainSpan Atlas of the Developing Human Brain demonstrates gene expression in the midgestational brain.

A paper describing this new atlas is published in the April 10 issue of Nature.

The paper focuses on the 15 to 21 weeks after conception during which the neocortex is forming. "We tried to take a deep, detailed look at this critical period of cortical development," lead author Ed Lein, PhD, an investigator at the Allen Institute for Brain Science in Seattle, Washington, told Medscape Medical News.

"This is the period when the cells are first being generated; they're migrating out and they're forming circuits. A disruption of this process during this period of time could very easily lead to a long-lasting functional consequence," he said.

Dr. Lein described the new atlas as "a marriage of classical anatomy with modern 'transcriptomics'."

As a framework for the atlas, researchers studied 4 donated, intact, high-quality human prenatal brains from preterm stillbirths — 2 from 15 to 16 weeks and 2 from 21 weeks after conception. Contributing labs provided data from a variety of genomic and imaging techniques.

An example plate from 1 of the BrainSpan Reference Atlases (21 weeks after conception).  These atlases are full-color, high-resolution, Web-based digital atlases of developing human brain structures, in high anatomic detail. Courtesy of Nature.com

Surprising Findings

The BrainSpan Atlas aims to inspire new hypotheses regarding human brain development and has already led to some surprising findings. For example, researchers have found significant differences between mouse and human brains in the subplate zone.

"What has become quite clear from our atlases — and we have atlases in the adult mouse, the developing mouse, the adult human, and now the developing human — is that when you compare the patterns between species, there are many differences," said Dr. Lein. "And these differences are turning out to be important in terms of clinical research."

In research on brain-based diseases, one must understand the basic biology in order to learn what normal processes may be disrupted. "This knowing when and where is incredibly important," said Dr. Lein.

In autism, for example, it's believed that candidate genes are expressed in the cortex very early. Finding the exact biological interruption early on could lead to diagnosis at a much earlier age, said Dr. Lein.

He and his colleagues have developed resources for researchers to use in their own work involving a particular gene or area of the brain. "We have created tools to do this special temporal data mining. For example, if you're interested in something in the precursor cells of the cortex at a particular stage in time, it will give you a list of genes that have that type of pattern," said Dr. Lein.

For free access to the brain atlas, visit www.brainspan.org.

Another recently published study uses another atlas — the Allen Institute's Mouse Brain Connectivity Atlas — to provide fresh insights into how the nervous system processes information.

These papers coincide with the first anniversary of President Obama's Brain Initiative.

The research is funded by the National Institutes of Mental Health. The authors have disclosed no relevant financial relationships.

Nature. Published online April 2, 2014. Prenatal atlas abstract Mouse brain atlas abstract

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