Single gene regulates motor neurons in spinal cord

Sep 08, 2010
This image shows the pattern of motor neuron innervation in the body of a mouse embryo. Credit: Image courtesy of Heekyung Jung

In a surprising and unexpected discovery, scientists at NYU Langone Medical Center have found that a single type of gene acts as a master organizer of motor neurons in the spinal cord. The finding, published in the September 9, 2010 issue of Neuron, could help scientists develop new treatments for diseases such as Lou Gehrig's disease or spinal cord injury.

The "master organizer" is a member of the Hox family of genes, best known for controlling the overall pattern of body development. By orchestrating a cascade of in the early embryo, Hox genes allow for the creation of an animal's overall structure and body part orientation. Scientists first discovered the genes in but they have since detected Hox activity in mammals. Humans harbor 39 such genes and 21 have been identified as coordinating in the spinal cord.

"We knew that there were 21 Hox genes that determine how connections are made between motor neurons in the spinal cord and muscles in the limbs," says Jeremy S. Dasen, PhD, an associate professor in the Departments of Physiology and Neuroscience at NYU Langone Medical Center and a Howard Hughes Medical Institute Early Career Scientist. "But what was surprising to us in this study was that a single Hox gene acts as a global organizer of motor neurons and their connections. The next step will be to see how Hoxc9 in motor neurons affect motor behaviors such as walking and breathing."

In mammals, many hundreds of motor neurons are needed to control the variety of used to coordinate movement. Proper function depends on each of these neurons in the embryo finding its way from the spinal cord to the group of muscles that it is equipped to control. Dr. Dasen and his colleagues have been working to discover the blueprint for this motor neuron diversity.

For this study, scientists studied mice with a mutation in Hoxc9 gene. They analyzed the molecular markers that distinguished between motor neurons in the limb and thoracic area and discovered mutation of Hoxc9 transformed the thoracic motor neurons into limb motor neurons. In a series of biochemical experiments they further showed that Hoxc9 orchestrates gene expression in motor neurons by repressing the dedicated to limb coordination.

"What we are trying to understand is how the nervous system is wired to control movements such as breathing and walking and see how genetic programs can further control these circuits in terms of exploring this paradigm as a way at looking at the vital circuits of the body," adds Dr. Dasen.

Explore further: Know the brain, and its axons, by the clothes they wear

add to favorites email to friend print save as pdf

Related Stories

Evolution of new brain area enables complex movements

Jan 12, 2009

A new area of the cerebral cortex has evolved to enable man and higher primates to pick up small objects and deftly use tools, according to neuroscientists at the University of Pittsburgh School of Medicine and Pittsburgh's ...

A fine balance

Oct 08, 2008

Once a toddler has mastered the art of walking, it seems to come naturally for the rest of her life. But walking and running require a high degree of coordination between the left and right sides of the body. ...

Antioxidant controls spinal cord development

Sep 18, 2009

Researchers at the Johns Hopkins School of Medicine have discovered how one antioxidant protein controls the activity of another protein, critical for the development of spinal cord neurons. The research, publishing this ...

Recommended for you

Know the brain, and its axons, by the clothes they wear

Apr 18, 2014

(Medical Xpress)—It is widely know that the grey matter of the brain is grey because it is dense with cell bodies and capillaries. The white matter is almost entirely composed of lipid-based myelin, but ...

Turning off depression in the brain

Apr 17, 2014

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Rapid whole-brain imaging with single cell resolution

Apr 17, 2014

A major challenge of systems biology is understanding how phenomena at the cellular scale correlate with activity at the organism level. A concerted effort has been made especially in the brain, as scientists are aiming to ...

User comments : 0

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.