Early Postnatal Starvation Causes Lasting Brain Hypomyelination

Rats were starved during various intervals of postnatal development, and subsequently, they were rehabilitated by feeding ad lib. through 60 days of age. Starvation was induced by an increasingly severe regime of maternal deprivation that results in a 50% deficit in body weight at 20 days. Relatively mild and brief starvation, from birth through 8 days, as well as more severe starvation occurring late, from 14 to 30 days, produced no lasting deficit in myelin accumulation. Starvation from birth through 14 days or from birth through 20 days produced lasting, significant myelin deficits in all regions (cerebrum, cerebellum, medulla, midbrain, hippocampus, hypothalamus, and striatum) of the brain. These data, in combination with our previous metabolic studies of myelin synthesis of starved and control rats, show that starvation early in development, during the period of oligodendroglial cell multiplication, accounts for an immediate reduction in myelin synthesis, and that the consequent myelin deficit proves irreversible in subsequent nutritional rehabilitation. In contrast, brain weight is subject to substantial growth catch‐up upon rehabilitation. Where the onset of starvation was late, during the period of rapid myelin synthesis, but after completion of the major period of oligodendroglial cell proliferation, no lasting myelin deficit was observed upon rehabilitation.