title: The glucocorticoid analog dexamethasone alters the expression and the distribution of dopamine receptors and enkephalin within cortico-subcortical regions.
abstract: In humans, glucocorticoid excess may cause neuropsychiatric symptoms, including psychosis and cognitive impairment, and glucocorticoid signaling hyperactivation may sensitize to substance of abuse. The aim of this work was to evaluate whether exposure to glucocorticoid excess triggers molecular changes in dopaminergic and opioidergic systems within relevant forebrain areas. We acutely exposed Sprague-Dawley rats to dexamethasone, a glucocorticoid analog, or vehicle and evaluated the mRNA expression of dopamine D1 and D2 receptors and enkephalin within the cortex, the striatum, and the midbrain. Dexamethasone reduced mRNA expression of D1 receptor and enkephalin in the cortex. In the striatum, dexamethasone reduced the expression of D1 receptor mRNA, but not that of D2 receptor and enkephalin. No significant changes in D2 receptor mRNA expression were observed in the midbrain. Basal distribution of D1 and D2 receptor mRNA showed a clear-cut striatal/cortical gradient, while this distribution was less obvious for enkephalin mRNA. Dexamethasone increased the cortico-striatal separation in terms of D1 and D2 receptor mRNA expression. These molecular changes may represent adaptive mechanisms to dexamethasone-induced potentiation of dopaminergic and opioidergic transmission, mostly in cortical areas.
authors.forename: Felice
authors.initials: F
authors.lastname: Iasevoli
authors.forename: Luigi
authors.initials: L
authors.lastname: Aloj
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Latte
authors.forename: Livia
authors.initials: L
authors.lastname: Avvisati
authors.forename: Federica
authors.initials: F
authors.lastname: Marmo
authors.forename: Carmine
authors.initials: C
authors.lastname: Tomasetti
authors.forename: Elisabetta F
authors.initials: EF
authors.lastname: Buonaguro
authors.forename: Chiara
authors.initials: C
authors.lastname: Simeoli
authors.forename: Rosario
authors.initials: R
authors.lastname: Pivonello
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
authors.affiliation: Department of Neuroscience, Reproductive Sciences and Odontostomatology, University "Federico II" of Napoli, Via Pansini 5, 80131 Naples, Italy. felix_ias@hotmail.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: de Bartolomeis
mesh_terms: D000818:Animals; D002525:Cerebellar Cortex / Q000187:drug effects / Q000378:metabolism; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology*; D004745:Enkephalins / Q000032:analysis / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D005938:Glucocorticoids / Q000494:pharmacology*; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000032:analysis / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000032:analysis / Q000235:genetics*
chemical_list: D004745:Enkephalins; D005938:Glucocorticoids; D012333:RNA, Messenger; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D003907:Dexamethasone