Via KurzweilAI: "researchers have uncovered a mechanism through which caloric restriction and exercise delay some of the debilitating effects of aging by rejuvenating the connections between nerves and the muscles that they control. ... Their research, conducted through laboratory mice genetically engineered so their nerve cells glow in fluorescent colors, shows that some of the debilitation of aging is caused by the deterioration of connections that nerves make with the muscles they control, structures called neuromuscular junctions. These microscopic links are remarkably similar to the synapses that connect neurons to form information-processing circuits in the brain. ... The work showed that mice on a restricted-calorie diet largely avoid that age-related deterioration of their neuromuscular junctions, while those on a one-month exercise regimen when already elderly partially reverse the damage. ... With calorie restriction, we saw reversal of all of these things. With exercise, we saw a reversal of most, but not all. ... Because of the study's structure - mice were on calorie-restricted diets for their whole lives, while those that exercised did so for just the month late in life - [the researchers] cautioned against drawing conclusions about the effectiveness of exercise versus calorie restriction in preventing or reversing synaptic damage. ... longer periods of exercise might have more profound effects."