Edward Callaway, a neuroscientist at the Salk Institute in San Diego, says these new findings are the first clear indication that larger structural changes occur in dendrites. But, he adds, researchers still need to show that these structural changes are linked to changes in the connections between neurons.

Nedivi and colleagues now plan to search for ways to boost the growth and plasticity of neurons, which could eventually provide a new approach to treating spinal cord injuries. They will also determine if such structural changes correlate with changes in learning and behavior, such as might occur after mice are challenged with a more stimulating environment or new tricks.

An additional area of interest, according to David Kleinfeld, a physicist who studies neurobiology at the University of California, San Diego, would be to investigate what happens to neurons in brain regions affected by stroke. "Blood vessels sprout in the 'dead zone' left after a stroke," he explains, "but it's unknown if you get sprouting of neurons at the same time."

The MIT researchers will also look at mouse models of diseases such as Alzheimer's, to figure out if neurons involved in such disorders grow too much, too little, or in the wrong way.

Image on home page courtesy of Elly Nedivi.