The behavioral effects of a single adverse exposure in a number of rat generations: the role of maternal glucocorticoids]

The ionizing irradiation of rat fetuses during the last third of intrauterine development increased blood corticosterone level adulthood and decreased the open field locomotion of their adult offsprings of the next first nonirradiated generation. Treatment of the pregnant rats with glucocorticoids also decreased the offspring locomotion. Irradiation of fetuses in the middle of embryogenesis decreased blood corticosterone level in adulthood and shortened the open-field freezing reaction of their adult offsprings of the next first nonirradiated generation. Adrenalectomy of females before mating decreasing the blood corticosterone level had a similar effect on freezing duration of their adult offsprings. Irradiation of the ancestors within the last third of their intrauterine development had no effect on blood corticosterone level of their adult offsprings of the first generation and produced no behavioral alterations in their descendants of the next second nonirradiated generation. Irradiation of the ancestors in the middle of their embryogenesis decreased the stress-induced corticosterone response in their adult offsprings of the first generation and increased rearings and locomotion in their descendants of the next second nonirradiated generation. The data suggest that a single noxious treatment may have behavioral effects throughout two consequent generations of rats. Mother's glucocorticoid hormones may be one of the factors which transmit the effect.