Researchers decode patterns that make our brains human

November 16, 2015, Allen Institute for Brain Science
Researchers prepare tissue used in the Allen Human Brain Atlas. Credit: Allen Institute for Brain Science

The human brain may be the most complex piece of organized matter in the known universe, but Allen Institute researchers have begun to unravel the genetic code underlying its function. Research published this month in Nature Neuroscience identified a surprisingly small set of molecular patterns that dominate gene expression in the human brain and appear to be common to all individuals, providing key insights into the core of the genetic code that makes our brains distinctly human.

"So much research focuses on the variations between individuals, but we turned that question on its head to ask, what makes us similar?" says Ed Lein, Ph.D., Investigator at the Allen Institute for Brain Science. "What is the conserved element among all of us that must give rise to our unique cognitive abilities and human traits?"

Researchers used data from the publicly available Allen Human Brain Atlas to investigate how gene expression varies across hundreds of functionally distinct brain regions in six human brains. They began by ranking genes by the consistency of their expression patterns across individuals, and then analyzed the relationship of these genes to one another and to brain function and association with disease.

"Looking at the data from this unique vantage point enables us to study gene patterning that we all share," says Mike Hawrylycz, Ph.D., Investigator at the Allen Institute for Brain Science. "We used the Allen Human Brain Atlas data to quantify how consistent the patterns of expression for various genes are across human brains, and to determine the importance of the most consistent and reproducible genes for brain function."

Despite the anatomical complexity of the brain and the complexity of the human genome, most of the patterns of gene usage across all 20,000 genes could be characterized by just 32 expression patterns. While many of these patterns were similar in human and mouse, the dominant genetic model organism for biomedical research, many genes showed different patterns in human. Surprisingly, genes associated with neurons were most conserved across species, while those for the supporting glial cells showed larger differences.

The most highly stable genes—the that were most consistent across all brains—include those that are associated with diseases and disorders like autism and Alzheimer's and include many existing drug targets. These patterns provide insights into what makes the distinct and raise new opportunities to target therapeutics for treating disease.

The researchers also found that the pattern of gene expression in cerebral cortex is correlated with "functional connectivity" as revealed by neuroimaging data from the Human Connectome Project. "It is exciting to find a correlation between brain circuitry and by combining high quality data from these two large-scale projects," says David Van Essen, Ph.D., professor at Washington University in St. Louis and a leader of the Human Connectome Project.

"The human brain is phenomenally complex, so it is quite surprising that a small number of patterns can explain most of the gene variability across the brain," says Christof Koch, Ph.D., President and Chief Scientific Officer at the Allen Institute for Brain Science. "There could easily have been thousands of , or none at all. This gives us an exciting way to look further at the functional activity that underlies the uniquely human brain."

Explore further: Human brains share consistent genetic blueprint and possess enormous biochemical complexity

More information: Canonical genetic signatures of the adult human brain, Nature Neuroscience, DOI: 10.1038/nn.4171

Related Stories

Human brains share consistent genetic blueprint and possess enormous biochemical complexity

September 19, 2012
Scientists at the Allen Institute for Brain Science reported in the latest issue of the journal Nature that human brains share a consistent genetic blueprint and possess enormous biochemical complexity. The findings stem ...

Fine-scale analysis of the human brain yields insight into its distinctive composition

April 12, 2012
Scientists at the Allen Institute for Brain Science have identified similarities and differences among regions of the human brain, among the brains of human individuals, and between humans and mice by analyzing the expression ...

For neurons in the brain, identity can be used to predict location

March 24, 2014
Throughout the world, there are many different types of people, and their identity can tell a lot about where they live. The type of job they work, the kind of car they drive, and the foods they eat can all be used to predict ...

Data release from the Allen Institute for Brain Science expands online atlas offerings

June 7, 2012
The Allen Institute for Brain Science announced today its latest public data release, enhancing online resources available via the Allen Brain Atlas data portal and expanding its application programming interface (API).

Two heads are better than one: Gene expression reveals molecular mechanisms underlying evolution of cerebral cortex

November 9, 2012
Dramatic expansion of the human cerebral cortex, over the course of evolution, accommodated new areas for specialized cognitive function, including language. Understanding the genetic mechanisms underlying these changes, ...

Recommended for you

Neurons can carry more than one signal at a time

July 18, 2018
Back in the early days of telecommunications, engineers devised a clever way to send multiple telephone calls through a single wire at the same time. Called time-division multiplexing, this technique rapidly switches between ...

Pregnancy history may be tied to Alzheimer's disease

July 18, 2018
A woman's history of pregnancy may affect her risk of Alzheimer's disease decades later, according to a study published in the July 18, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology. ...

Researchers solve mystery of how ALL enters the central nervous system

July 18, 2018
A deadly feature of acute lymphoblastic leukemia (ALL) is its invasion of the central nervous system.

Forty percent of people have a fictional first memory, says study

July 17, 2018
Researchers have conducted one of the largest surveys of people's first memories, finding that nearly 40 per cent of people had a first memory which is fictional.

Protein found to be key component in irregularly excited brain cells

July 17, 2018
In a new study in mice, researchers have identified a key protein involved in the irregular brain cell activity seen in autism spectrum disorders and epilepsy. The protein, p53, is well-known in cancer biology as a tumor ...

New drug target for remyelination in MS is identified

July 17, 2018
Remyelination, the spontaneous regeneration of the fatty insulator in the brain that keeps neurons communicating, has long been seen as crucial to the next big advance in treating multiple sclerosis (MS). However, a lack ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.