Alterations in behavioral and striatal dopamine asymmetries induced by prenatal stress.

We investigated the effects of maternal noise and light stress, randomly applied throughout pregnancy, on the development of behavioral and neurochemical asymmetries in the rat offspring. This form of maternal stress resulted in a rightward positioning of the tail of both sexes soon after birth as opposed to the leftward bias in controls. At adulthood, prenatally stressed offspring showed a change in directional bias compared to controls with a preponderance of left turns after amphetamine. In the males, this was expressed as a reduction in directional preference, while in females a reversal occurred of their dominant turning direction from right (controls) to left. We also observed a reduction in dopamine turnover rates in the left corpora striata of stressed offspring of both sexes. Again, in the females, this change was particularly marked and resulted in a reversal towards the right hemisphere. The findings from this study are consistent with the possibility that the alterations in cerebral asymmetries induced by prenatal stress may underly the decrease in the ability of the offspring to cope with anxiety provoking situations.