title: Estrogen influences cocaine-induced blood oxygen level-dependent signal changes in female rats.
abstract: We investigated the effect of estrogen on cocaine-induced brain activity using blood oxygen level-dependent (BOLD) magnetic resonance imaging. Ovariectomized (Ovx) rats without estrogen and Ovx rats with estrogen (Ovx+E) were given a single saline or cocaine injection (15 mg/kg, i.p.) for 5 d. After 7 d of withdrawal from injections, rats were challenged with cocaine during functional imaging. Acute cocaine administration produced positive BOLD activation in the prefrontal cortex, nucleus accumbens, striatum, ventral tegmental area, and hippocampus, among other brain regions. Positive BOLD signal changes were lower in Ovx+E than in Ovx rats. With repeated cocaine administration, Ovx+E rats showed enhanced BOLD signal changes in the nucleus accumbens, ventral tegmental area, and hippocampus compared with acutely treated animals. Our results indicate that estrogen influences the effects of acute and repeated cocaine administration on BOLD signal changes. The data suggest that in females with estrogen, cocaine-induced neuronal activity is enhanced after repeated cocaine administration. It is possible that the actions of estrogen within the aforementioned brain regions potentiate the behavioral response to cocaine observed in female rats.
authors.affiliation: Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA. Marcelo.Febo@umassmed.edu
authors.forename: Marcelo
authors.initials: M
authors.lastname: Febo
authors.forename: Craig F
authors.initials: CF
authors.lastname: Ferris
authors.forename: Annabell C
authors.initials: AC
authors.lastname: Segarra
mesh_terms: D000818:Animals; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology* / Q000633:toxicity; D004958:Estradiol / Q000494:pharmacology* / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000098:blood supply / Q000187:drug effects; D006935:Hypercapnia / Q000139:chemically induced; D008279:Magnetic Resonance Imaging; D009714:Nucleus Accumbens / Q000098:blood supply / Q000187:drug effects; D010052:Ovariectomy; D010100:Oxygen / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013681:Tegmentum Mesencephali / Q000098:blood supply / Q000187:drug effects
chemical_list: D004958:Estradiol; D003042:Cocaine; D010100:Oxygen