Effect of neonatal hydrocortisone treatment on brain monoamines in developing rats.

Abstract

Neonatal treatment with hydrocortisone produced a marked retardation of pituitary-adrenocortical development in infant rats. Whether or not the retarded activity is due to functional changes in brain monoamine synthesis was studied. In rats treated with hydrocortisone (0.5 mg/rat, s.c.) on the 2nd day of life, the development of whole brain was suppressed significantly. Norepinephrine, dopamine and serotonin contents in the brain were higher in these rats than in controls. These changes of monoamine contents were apparent in the hypothalamus, diencephalon and pons-medulla oblongata. Monoaminergic nervous systems are potentiated with hydrocortisone in these brain regions, but the results do not necessarily explain the retarded hypothalamo-pituitary function.