¨Long Term Effects of Prenatal Stress and Early Adoption on Dopamine and Glutamate Receptors in Adult Rat Brain¨

VG BARROS; L BOADO; R CAVIEDES; P CAVIEDES; MC ANTONELLI

La Serena

Congreso; Primera Reunión de la Neurotoxicity Society; 2003

Neurotoxicity Society

Stressful stimuli during pregnancy induced behavioral and neurochemical alterations in adulthood that can be reversed by environmental manipulations during the early postnatal period. Repeated restraint during the last week of pregnancy was used as a model of prenatal stress and adoption at birth was used to change the postnatal environment. Dopamine D2 receptors , and glutamate NMDA receptors increased in limbic areas of adult offspring of rats stressed during pregnancy, but this increase was reverted by cross-fostering procedures. Even though the mechanism underlying the increase of DA receptors is unknown, high levels of corticosterone secreted in response to stress by the pregnant animal may be a predisposing factor. To test this hypothesis, cultured cells from a mouse cerebral cortex neuronal cell line (CNh) were incubated with corticosterone and D4 receptor expression, one of the D2 family members, was detected by immunocytochemistry. 10 ìM corticosterone decreased receptor expression suggesting that changes in dopamine receptors are not produced by the direct action of the hormone. The complex pattern of receptor changes reflects the high vulnerability of dopamine and glutamate receptor expression to variations in maternal care and postnatal handling.The changes are either not exerted directly through the elevated levels of circulating corticosterone, or result from the interaction of various stimuli. Supported by: CONICET, Ministerio de Salud (Argentina), DID Enlaces 2002 (Univ. of Chile) and Fondation J. Lejeune, France., and glutamate NMDA receptors increased in limbic areas of adult offspring of rats stressed during pregnancy, but this increase was reverted by cross-fostering procedures. Even though the mechanism underlying the increase of DA receptors is unknown, high levels of corticosterone secreted in response to stress by the pregnant animal may be a predisposing factor. To test this hypothesis, cultured cells from a mouse cerebral cortex neuronal cell line (CNh) were incubated with corticosterone and D4 receptor expression, one of the family members, was detected by immunocytochemistry. 10 ìM corticosterone decreased receptor expression suggesting that changes in dopamine receptors are not produced by the direct action of the hormone. The complex pattern of receptor changes reflects the high vulnerability of dopamine and glutamate receptor expression to variations in maternal care and postnatal handling.The changes are either not exerted directly through the elevated levels of circulating corticosterone, or result from the interaction of various stimuli. Supported by: CONICET, Ministerio de Salud (Argentina), DID Enlaces 2002 (Univ. of Chile) and Fondation J. Lejeune, France.