March 19, 2012 5:45 AM
Kathryn Hobgood Ray
Causes of neuro-developmental disorders such as mental retardation, schizophrenia and autism continue to challenge the medical community, but researchers at Tulane University potentially have found a key. They demonstrated how a particular gene is essential to the healthy development of infant brains, and if it’s missing, may lead to disorders.
The gene GluN2B encodes a neurotransmitter receptor subunit that plays a critical role in controlling protein translation and synaptic plasticity in the brain during a vital developmental period.
“Synaptic plasticity is at the heart of our cognitive abilities, including our ability to learn and store information about the world,” explains Ben Hall, assistant professor of cell and molecular biology.
Hall and his team examined the role of GluN2B in the brains of young mice. In infancy, GluN2B dominates neurotransmitter receptors at synapses in the cortex, whereas GluN2A largely replaces the early protein in the adult brain. This change occurs in humans during early developmental stages, Hall says.
How would the loss of these receptors affect animal behavior? “We decided to tackle this issue using a genetic approach,” Hall says. “We actually removed the gene that encodes GluN2B and replaced it with a copy of the GluN2A gene.”
The results were dramatic. The findings were published in the journal Neuron.
“The mice were significantly less social than normal animals,” Hall says. “Usually young mice will spend more time engaged in social interaction when presented with a choice of investigating another animal or investigating a familiar object. In these controlled experiments, we found that our animals were less interested in social interaction (almost completely uninterested) even though they were more active in terms of their motor behavior.”
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