title: Altered neurochemical levels in the rat brain following chronic nicotine treatment.
abstract: Converging evidence shows that neurochemical systems are crucial mediators of nicotine dependence. Our present study evaluates the effect of 3-month chronic nicotine treatment on the levels of multiple quaternary ammonium compounds as well as glutamate and gamma aminobutyric acid in the rat prefrontal cortex, dorsal striatum and hypothalamus. We observed a marked decrease of acetylcholine levels in the dorsal striatum (22.88%, p<0.01), reflecting the impact of chronic nicotine in local interneuron circuits. We found decreases of carnitine in the dorsal striatum and prefrontal cortex (19.44%, p<0.01; 13.58%, p<0.01, respectively), but robust enhancements of carnitine in the hypothalamus (26.59%, p<0.01), which may reflect the alterations in food and water intake during chronic nicotine treatment. Finally, we identified an increase of prefrontal cortex glutamate levels (8.05%, p<0.05), supporting previous studies suggesting enhanced prefrontal activity during chronic drug use. Our study shows that quaternary ammonium compounds are regulated in a highly brain region specific manner during chronic nicotine treatment, and provides novel insights into neurochemical regulation during nicotine use.
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland.
authors.forename: Sara
authors.initials: S
authors.lastname: Falasca
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland.
authors.forename: Vaclav
authors.initials: V
authors.lastname: Ranc
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland.
authors.forename: Filomena
authors.initials: F
authors.lastname: Petruzziello
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland.
authors.forename: Abbas
authors.initials: A
authors.lastname: Khani
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Kretz
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland. Electronic address: xiaozhe.zhang@unifr.ch.
authors.forename: Xiaozhe
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musee 5, Fribourg CH-1700, Switzerland; Fribourg Center for Cognition, University of Fribourg, Fribourg CH-1700, Switzerland.
authors.forename: Gregor
authors.initials: G
authors.lastname: Rainer
mesh_terms: D000109:Acetylcholine / Q000032:analysis / Q000096:biosynthesis; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002331:Carnitine / Q000032:analysis / Q000096:biosynthesis; D002853:Chromatography, Liquid; D018698:Glutamic Acid / Q000032:analysis / Q000096:biosynthesis; D013058:Mass Spectrometry; D009538:Nicotine / Q000633:toxicity*; D018722:Nicotinic Agonists / Q000633:toxicity*; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D018722:Nicotinic Agonists; D018698:Glutamic Acid; D009538:Nicotine; D000109:Acetylcholine; D002331:Carnitine
keywords: Chronic nicotine; Dorsal striatum; Hypothalamus; Neurochemicals; Prefrontal cortex