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: Defects in brain cell migration linked to mental retardation

Related Stories

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 ...

Recommended for you

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

No cable spaghetti in the brain

November 24, 2015

Our brain is a mysterious machine. Billions of nerve cells are connected such that they store information as efficiently as books are stored in a well-organized library. To this date, many details remain unclear, for instance ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

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.