Prenatal and Postnatal Protein Restriction in the Rat: Effect on Some Parameters Related to Brain Development, and Prospects for Rehabilitation1,2

From the third day of pregnancy rats were fed a diet containing either 7% casein (experimental) or 24% casein (control). During lactation the control dams were fed the 24% casein diet and the experimental dams a 12% casein diet. From 25 to 50 days of age the experimental and control progeny were fed diets containing 7 and 24% casein, respectively. Between 50 and 120 days both groups were fed a diet containing 24% crude protein. Several indications of brain maturation in two brain areas were examined at various stages of development. In addition to retardation of brain growth, protein restriction led to myelin of an immature composition at 25 and 50 days of age. The immature composition was indicated by a low plasmalogen content at 25 days and by a high phospholipid and low galactolipid and plasmalogen contents at 50 days of age. The activity of the myelin marker enzyme, 2′3′‐cyclic nucleotide 3′‐phosphohydrolase (CNP), was significantly lower in the brains (excluding the cerebella) of malnourished rats at 21, 30 and 50 days. At all ages except at 50 days the activity of CNP in the cerebellum was higher in protein‐deprived animals than in controls. The activity of glutamic acid decarboxylase (GAD) in the brains (excluding the cerebella) of protein‐deprived rats was significantly lower at 21, 25 and 30 days but not at 50 and 65 days of age. As indicated by brain/body ratios, myelin composition and GAD activity, nutritional rehabilitation led to almost complete recovery of brain maturity, but the activity of CNP remained lower in the experimental group after rehabilitation.