The influence of pre- and postnatal undernutrition on the developing brain stem reticular core: a quantitative Golgi study.

Neurons of the brain stem reticular core were examined in rats which had been exposed to prenatal or postnatal undernutrition. Prenatal undernutrition was induced by restricting maternal diet to 2/3 of ad libitum prior to and during the gestation period. Postnatal restriction to 20 days of age was induced by increasing the litter to 14 and removing the dam for 8 h each day. Both imposed experimental conditions tended to delay the course of reticular neuron development as indicated by altered number of dendritic protospines and varicosities. However, the effects of prenatal undernutrition were more severe. At birth, the amount of DNA in the brain stem was reduced (-24%) while average dendritic extent and branching were greatly increased. Early undernutrition appears to have a profound effect on the quality of the neuropil, both neuronal and glial, while postnatal exposure does not influence the structure of the dendritic arbor.