[Effect of serotonin deficit at different stages of prenatal ontogenesis on behavior of adult male and female rats].

Effects of maternal parachlorophenilalanine (PCPA) administration on the offspring behavior were studied in the open field, Porsolt forced swimming, and Morris water maze tests. PCPA was administered in two different gestational periods: on gestational days (GD) 8-11 or GD 14-17, at doses 200/100/100/50 mg/kg. It was found that prenatal exposure to PCPA results in fetal serotonin (5-HT) depletion and changes in both open field activity and depression-related behavior, as well as impairments in spatial learning in the adult offspring. The most pronounced effects on behavior were observed in the male and female offspring whose mothers were depleted of serotonin by PCPA during the third trimester of pregnancy. These results provide further evidence that adverse factors have the most severe effects on the development of rat brain function when exposed during the final trimester of pregnancy than during the second trimester.