Scientists find new clues to brain's wiring

July 18, 2014 by Michael C. Purdy

New research provides an intriguing glimpse into the processes that establish connections between nerve cells in the brain. These connections, or synapses, allow nerve cells to transmit and process information involved in thinking and moving the body.

Reporting online in Neuron, researchers at Washington University School of Medicine in St. Louis have identified a group of proteins that program a common type of brain nerve cell to connect with another type of nerve cell in the brain.

The finding is an important step forward in efforts to learn how the developing brain is built, an area of research essential to understanding the causes of intellectual disability and autism.

"We now are looking at how loss of this wiring affects brain function in mice," said senior author Azad Bonni, MD, PhD, the Edison Professor of Neurobiology and head of the Department of Anatomy and Neurobiology at the School of Medicine.

Bonni and his colleagues are studying synapses in the , a region of the brain that sits in the back of the head. The cerebellum plays a central role in controlling the coordination of movement and is essential for what researchers call procedural motor learning, which makes it possible to move our muscles at an unconscious level, such as when we ride a bicycle or play the piano.

"The cerebellum also regulates mental functions," Bonni said. "So, impairment of the wiring of in the cerebellum may contribute to movement disorders as well as cognitive problems including ."

His new results show that a complex of proteins known as NuRD (nucleosome remodeling and deacetylase) plays a fairly high supervisory role in some aspects of the cerebellum's construction. When the researchers blocked the NuRD complex, cells in the cerebellum called failed to form connections with other nerve cells, the Purkinje neurons. These circuits are important for the cerebellum's control of movement coordination and learning.

Bonni and his colleagues showed that NuRD exerts influence at the epigenetic level, which means it controls factors other than DNA that affect gene activity. For example, NuRD affects the configurations of molecules that store DNA and that can open and close the coils of DNA like an accordion, making less or more accessible. Changing the accessibility of genes changes their activity levels. For instance, cells can't frequently make proteins from genes in a tightly packed coil of DNA.

NuRD also alters tags on the proteins that store DNA, decreasing the chances that the gene will be used. Among the genes deactivated by NuRD are two that control the activity of other genes involved in the wiring of the cerebellum.

"This tells us that the NuRD complex is very influential—not only does it affect the activity of genes directly, it also controls other regulators of multiple genes," Bonni said.

Explore further: Intellectual disability linked to nerve cells that lose their 'antennae'

Related Stories

Intellectual disability linked to nerve cells that lose their 'antennae'

August 30, 2013
(Medical Xpress)—An odd and little-known feature of nerve cells may be linked to several forms of inherited intellectual disability, researchers at Washington University School of Medicine in St. Louis have learned.

Team finds gene critical for development of brain motor center

June 21, 2014
(Medical Xpress)—In a report published today in Nature Communications, an Ottawa-led team of researchers describe the role of a specific gene, called Snf2h, in the development of the cerebellum. Snf2h is required for the ...

Defects in brain cell migration linked to mental retardation

June 21, 2013
(Medical Xpress)—A rare, inherited form of mental retardation has led scientists at Washington University School of Medicine in St. Louis to three important "travel agents" at work in the developing brain.

New insights into control of neuronal circuitry could lead to treatments for an inherited motor disorder

September 20, 2013
The cerebellum is a region of the brain critical for balance, learning of motor skills and coordination of movements. In the outer layer of the cerebellum, individual 'Purkinje' cells integrate inputs from the brain stem ...

Mechanism explains complex brain wiring

June 11, 2014
How neurons are created and integrate with each other is one of biology's greatest riddles. Researcher Dietmar Schmucker from VIB-KU Leuven unravels a part of the mystery in Science magazine. He describes a mechanism that ...

Controlling movements with light

July 20, 2011
German researchers at the Ruhr-Universitaet have succeeded in controlling the activity of certain nerve cells using light, thus influencing the movements of mice. By changing special receptors in nerve cells of the cerebellum ...

Recommended for you

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

Brain stimulation may improve cognitive performance in people with schizophrenia

July 24, 2017
Brain stimulation could be used to treat cognitive deficits frequently associated with schizophrenia, according to a new study from King's College London.

New map may lead to drug development for complex brain disorders, researcher says

July 24, 2017
Just as parents are not the root of all their children's problems, a single gene mutation can't be blamed for complex brain disorders like autism, according to a Keck School of Medicine of USC neuroscientist.

Bird songs provide insight into how developing brain forms memories

July 24, 2017
Researchers at the University of Chicago have demonstrated, for the first time, that a key protein complex in the brain is linked to the ability of young animals to learn behavioral patterns from adults.

Research identifies new brain death pathway in Alzheimer's disease

July 24, 2017
Alzheimer's disease tragically ravages the brains, memories and ultimately, personalities of its victims. Now affecting 5 million Americans, Alzheimer's disease is the sixth leading cause of death in the U.S., and a cure ...

Illuminating neural pathways in the living brain

July 24, 2017
Using light alone, scientists from the Max Planck Institute of Neurobiology in Martinsried are now able to reveal pairs or chains of functionally connected neurons under the microscope. The new optogenetic method, named Optobow, ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

russell_russell
1 / 5 (1) Jul 19, 2014
What part of procedural motor learning is improvisatory piano playing?
Only different expressions of the sense of balance is required for new bicycle antics.

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.