WEDNESDAY, May 23, 2007 (HealthDay News) -- Scientists are gaining new insights into how older brains stay young.
A team at Johns Hopkins University, Baltimore, says the continual formation of new brain cells (neurons) in adults may help give their brains the same kind of learning ability seen in young people's brains. At the same time, existing, mature brain cells maintain the adult brain's stability, they say.
The study is published in the May 24 issue of the journal Neuron.
The researchers used molecular analysis to study the hippocampus (which plays a major role in learning and memory) in the brains of adult mice.
They found that, when first formed, new adult brain cells had a level of adaptability that was similar to that of brain cells in newborn animals. This plasticity lasted for a limited period of time before the new adult brain cells showed the less "plastic" characteristics of mature brain cells.
The study also found that the plasticity of new adult brain cells was dependent on the function of one of the same types of receptors associated with learning-related processes in newborn animals.
Since the adult form of critical-period elasticity resembles that seen in young brains, "adult-born neurons within the critical period may serve as major mediators for experience-driven plasticity" in later life, the researchers wrote.
In conclusion, the production of new neurons in adulthood, may "represent not merely a replacement mechanism for lost neurons but instead [be] an ongoing developmental process that continuously rejuvenates the mature nervous system by offering expanded capacity of plasticity in response to experience throughout life," the Baltimore team wrote.
The U.S. National Institute of Neurological Disorders and Stroke has more about neurons.