NEW YORK (June 6, 2013) -- Researchers at Weill Cornell Medical College have uncovered a mechanism that guides the exquisite wiring of neural circuits in a developing brain -- gaining unprecedented insight into the faulty circuits that may lead to brain disorders ranging from autism to mental retardation.
In the journal Cell, the researchers describe, for the first time, that faulty wiring occurs when RNA molecules embedded in a growing axon are not degraded after they give instructions that help steer the nerve cell. So, for example, the signal that tells the axon to turn -- which should disappear after the turn is made -- remains active, interfering with new signals meant to guide the axon in other directions.
The scientists say that there may be a way to use this new knowledge to fix the circuits.
"Understanding the basis of brain miswiring can help scientists come up with new therapies and strategies to correct the problem," says the study's senior author, Dr. Samie Jaffrey, a professor in the Department of Pharmacology.
"The brain is quite 'plastic' and changeable in the very young, and if we know why circuits are miswired, it may be possible to correct those pathways, allowing the brain to build new, functional wiring," he says.
Disorders associated with faulty neuronal circuits include epilepsy, autism, schizophrenia, mental retardation and spasticity and movement disorders, among others.
In their study, the scientists describe a process of brain wiring that is much more dynamic than was previously known -- and thus more prone to error.
Proteins Sense the Environment to Steer the Axon
During brain development, neurons have to connect to each other, which they do by extending their long axons to touch one another. Ultimately, these neurons form a circuit between the brain and the target tissue through which chemical and electrical signals are relayed. In this study,
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Weill Cornell Medical College