Effect of brain growth stages on T-maze acquisition in mice.

Recently, it has been shown that brain growth is characterized by periods of especially large increases in growth, with "plateaus" in growth between these "spurt" periods. In humans, these spurts in brain growth are correlated with spurts in mind growth, collectively termed phrenoblysis. Brain growth spurts in rodents occur at 0-6, 8-12, and 17-23 days of age with plateaus in-between. We examined two questions. First, are there differences in learning ability associated with spurts and plateaus in brain growth? Second, can learning during these stages be altered through genetic and environmental manipulations? We employed the high and low lines of the Fuller brain weight selection mice, which are known to have different developmental patterns, and early handling procedures, known to alter growth rates. The results showed that animals tested during a proposed brain growth spurt were superior to animals tested during a brain growth plateau in learning a shock-escape T-maze.