Old brains can be young again?

Neurogenesis briefly gives adult brains similar plasticity to that seen in infant brains, according to results from a new mouse study published this week in Neuron. Researchers found that new neurons between four to six weeks of age in the adult mouse brain undergo a brief critical period of increased adaptability to stimuli before maturing, a similar process to what occurs in newborn animals. "I think it's very interesting, and it suggests that these new neurons go through different developmental stages functionally and that at a specific period after their production, they may be especially sensitive to stimuli involved in learning," Elizabeth Gould of Princeton University in Princeton, N.J., who was not involved with the study, told The Scientist.Scientists have long debated the physiological behavior of new neurons in the adult brain. Behavioral studies suggest that new neurons in adult brains have to mature for one to three...