A-T is a rare disease characterized by the death of brain cells, which results in a progressive loss of motor control that typically, by adolescence, confines patients to wheelchairs. While the cell death appears first in the cerebellum, the brain region that directs movement, it eventually occurs throughout the brain.
| Courtesy of JThe Salk Institute |
 Carrolee Barlow |
By monitoring the number of revolutions each mouse lapped on a running wheel that was placed in its cage, the researchers actually discovered that the miles logged by these mice appeared to correlate directly with increased cell numbers. "We were stunned by that," says Salk assistant professor Carrolee Barlow, the study's lead author. "It's almost as if they were wearing pedometers, and those that ran more grew more cells," she says.
In the sedentary A-T mice, however, the team found that most newly born brain cells died. "We don't understand that fully, but it ...
