Prenatal influence of ischemia-hypoxia-induced intrauterine growth retardation on brain development and behavioral activity in rats

The effects of intrauterine growth retardation (IUGR) on brain histological or functional development were examined in rats. IUGR was induced by ligat ing the bilateral uterine arteries at day 17 of pregnancy. On day 22 of pre gnancy, cesarean section was performed, and pups with a birth weight of <2 SD of the mean birth weight of control pups were regarded as IUGR rats. Mor phological changes of the brain were studied by Nissl's staining at differe nt timepoints during prenatal and postnatal periods. For behavioral study, an open-field test was performed at 5, 7 and 10 weeks after birth. Histolog ical studies showed the migration disorder of the neurons in the cerebral c ortex from embryonic day 17 to postnatal day (PD) 49. The open-field test r evealed locomotor disturbance at PD49 in male IUGR rats, but not in female IUGR rats or control rats. It is concluded that IUGR due to antenatal ische mia-hypoxia causes morphological changes in the central nervous system, and induces behavioral impairment, particularly in male rats. Copyright (C) 20 01 S. Karger AG, Basel.