Corticosterone Upregulates Gene and Protein Expression of Catecholamine Markers in Organotypic Brainstem Cultures

Abstract

Glucocorticoids are produced by the adrenal cortex and regulate cell metabolism in a variety of organs. This occurs either directly, by acting on specific receptors in a variety of cells, or by stimulating catecholamine expression within neighbor cells of the adrenal medulla. In this way, the whole adrenal gland may support specific metabolic requirements to cope with stressful conditions from external environment or internal organs. In addition, glucocorticoid levels may increase significantly in the presence of inappropriate secretion from adrenal cortex or may be administered at high doses to treat inflammatory disorders. In these conditions, metabolic alterations and increased blood pressure may occur, although altered sleep-waking cycle, anxiety, and mood disorders are frequent. These latter symptoms remain unexplained at the molecular level, although they overlap remarkably with disorders affecting catecholamine nuclei of the brainstem reticular formation. In fact, the present study indicates that various doses of glucocorticoids alter the expression of genes and proteins, which are specific for reticular catecholamine neurons. In detail, corticosterone administration to organotypic mouse brainstem cultures significantly increases Tyrosine hydroxylase (TH) and Dopamine transporter (DAT), while Phenylethanolamine N-methyltransferase (PNMT) is not affected. On the other hand, Dopamine Beta-Hydroxylase (DBH) increases only after very high doses of corticosterone.

Keywords

• glucocorticoids
• noradrenaline
• dopamine
• tyrosine hydroxylase
• reticular formation
• dopamine transporter