INFLUENCE OF MATERNAL ADRENALECTOMY AND GLUCOCORTICOID ADMINISTRATIONON THE DEVELOPMENT OF RAT CEREBRAL-CORTEX

In order to determine the incidence of maternal glucocorticoids on mor phological parameters in fetal development, we performed optic and ele ctron microscopic analysis of the cerebral cortex of fetuses of 16 and 20 days of gestation, from control (C) and pregnant rats bilaterally adrenalectomized on clay 1 of gestation (ADX). We also studied fetuses 20 days old from pregnant rats betamethasone-injected on days 15, 16 and 17 (BET), and adrenalectomized on day 1 and betamethasone-injected on days 15, 16 and 17 (ADX+BET). Absence of maternal glucocorticoids during gestation caused, in fetuses 16 and 20 days old, a marked incre ase of cellular density, laxity of tissue and lower cellular maturatio n in comparison with the control group. Betamethasone injected into sh am-operated animals (BET) caused a slight advance in relation to contr ols in developmental parameters such as cellular density, maturation a nd synapse formation. Betamethasone injection into adrenalectomized an imals prevented. the lower degree of maturation characteristic of the adrenalectomized group, although an increase of cellular density could be detected. The cerebral cortex from fetuses of 16 days of gestation from adrenalectomized mothers also showed an increase of cellular den sity as compared with the control group. These results show that gluco corticoids participate in prenatal rat brain in control mechanisms of cellular division and maturation.