THE EFFECTS OF PRENATAL EXPOSURE TO HYPOXIA ON THE BEHAVIOR OF RATS DURING THEIR LIFE-SPAN

The aim of this study was to investigate the influence of moderate pre natal damage on adaptability during the juvenile, adult, and senile ph ases. Pregnant rats were exposed to a 12% normobaric hypoxia from day 1 to 17 postconception. Pregnancy was normal in both the treated anima ls and the controls. Erythrocytes, hemoglobin, and hematocrit did not increase in the treated pregnant animals. During the first 3 weeks, th e F1 generation showed developmental deviations in physiological chara cteristics. Throughout subsequent ontogeny, motor performance, cogniti ve ability, and adaptability to physical stress were determined with a test battery of varying demands. Some of the differences (e.g., locom otor activity, learning ability) between juvenile untreated and treate d rats disappeared during the adult phase. Motor and coordinative abil ities, however, remained partially impaired in the old rats, especiall y under high demands. This study, and previous findings with alcohol ( 37), indicate that prenatal exposure to a noxa may result in a highly differentiated brain injury pattern. Depending on the different functi ons, damage may intensify age-dependent adaptive disorders or provoke impairment without influencing the course of development.