DEXAMETHASONE TARGET SITES IN THE CENTRAL-NERVOUS-SYSTEM AND THEIR POTENTIAL RELEVANCE TO MENTAL-ILLNESS

1. The topical distribution of tritiated dexamethasone (DEX), a potent synthetic glucocorticoid of widespread use in the diagnosis and asses sment of mental illness, was studied in rat CNS by autoradiography to obtain information on potential traget sites for feedback and other ce ntrally mediated effects of glucocorticoids. 2. The cells of the arcua te nucleus of the hypothalamus and the lateral thalamic nuclei display ed the most concentrated nuclear accumulation of silver grains. 3. Sig nificant accumulation, exceeding that found in the hippocampal formati on, also occurred in the cells of the ventromedial, periventricular, a nd paraventricular nuclei of the hypothalamus, the locus ceruleus, the nucleus tractus solitarii, and the area postrema, none of which are t argeted by corticosterone, the native glucocorticoid of the rat. 4. Nu clear accumulation of silver grains was prominent in neural and glial cells of the cerebral cortex, the olfactory nucleus, the dorsolateral septum, the amygdala, the subfornical organ, the lateral parabrachial, medial trapezoid, and dorsal reticular nuclei, the nucleus centralis of the raphe, the cerebellum, and vascular tissues.