Nicotine is the main psychoactive ingredient in tobacco and its rewarding effects are considered primarily responsible for persistent tobacco smoking and relapse. Although dopamine has been extensively implicated in the rewarding effects of nicotine, noradrenergic systems may have a larger role than previously suspected. This study evaluated the role of noradrenergic alpha(1) receptors in nicotine and food self-administration and relapse, nicotine discrimination, and nicotine-induced dopamine release in the nucleus accumbens in rats. We found that the noradrenergic alpha(1) receptor antagonist prazosin (0.25-1 mg/kg) dose dependently reduced the self-administration of nicotine (0.03 mg/kg), an effect that was maintained over consecutive daily sessions; but did not reduce food self-administration. Prazosin also decreased reinstatement of extinguished nicotine seeking induced by either a nicotine prime (0.15 mg/kg) or nicotine-associated cues, but not food-induced reinstatement of food-seeking, and decreased nicotine-induced (0.15 mg/kg) dopamine release in the nucleus accumbens shell. However, prazosin did not have nicotine-like discriminative effects and did not alter the dose-response curve for nicotine discrimination. These findings suggest that stimulation of noradrenergic alpha(1) receptors is involved in nicotine self-administration and relapse, possibly via facilitation of nicotine-induced activation of the mesolimbic dopaminergic system. The findings point to alpha(1) adrenoceptor blockade as a potential new approach to the treatment of tobacco dependence in humans.
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http://dx.doi.org/10.1038/npp.2010.42 | DOI Listing |
Cells
December 2024
Neuroscience Institute, Section of Padova, National Research Council (CNR), 35131 Padova, Italy.
Astrocytes from different brain regions respond with Ca elevations to the catecholamine norepinephrine (NE). However, whether this noradrenergic-mediated signaling is present in astrocytes from the ventral tegmental area (VTA), a dopaminergic circuit receiving noradrenergic inputs, has not yet been investigated. To fill in this gap, we applied a pharmacological approach along with two-photon microscopy and an AAV strategy to express a genetically encoded calcium indicator in VTA astrocytes.
View Article and Find Full Text PDFMetabolites
December 2024
Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02453, Republic of Korea.
Background: Paclitaxel is a widely used anticancer drug for ovarian, lung, breast, and stomach cancers; however, its clinical use is often limited by the side effects of peripheral neuropathy. This study evaluated the effects of () extract and its active metabolite, α-cyperone, on paclitaxel-induced neuropathic pain.
Methods: The oral administration of extract at doses of 500 mg/kg and intraperitoneal administration of α-cyperone at doses of 480 and 800 μg/kg prevented both the development of cold and mechanical pain.
Elife
November 2024
Department of Anesthesiology, Zhejiang University School of Medicine, Hangzhou, China.
bioRxiv
September 2024
Department of Internal Medicine, Section of Pulmonary, Critical Care, and Sleep Medicine, School of Medicine, Yale University, New Haven, CT, USA.
Tissue fibrosis contributes to pathology in vital organs including the lung. Curative therapies are scant. Myofibroblasts, pivotal effector cells in tissue fibrosis, accumulate via incompletely understood interactions with their microenvironment.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
September 2024
Endocrinology, Diabetes and Metabolism; Department of Medical Sciences; University of Turin, Turin, Italy.
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