The relationship between nutritional adequacy and brain myelin accumulation: a comparison of varying degrees of well fed and undernourished rats.

Rats undernourished through 17 days of age to produce mild weight lag (less than 20%) had either the same amount, or slightly more myelin than well fed controls. Schedules of undernourishment producing approximately 30, 40 and 50% body weight lags produced corresponding rank-ordered myelin deficits of 25, 55 and 60%, respectively. Brain growth was relatively spared in all cases, never exceeding a deficit of 10%. Absolute myelin deficits did not recover following nutritional rehabilitation, although myelin continued to increase in both normal and all test populations.