title: Nicotine, alcohol and cocaine coupling to reward processes via endogenous morphine signaling: the dopamine-morphine hypothesis.
abstract: Pleasure is described as a state or feeling of happiness and satisfaction resulting from an experience that one enjoys. We examine the neurobiological factors underlying reward processes and pleasure phenomena. With regard to possible negative effects of pleasure, we focus on addiction and motivational toxicity. Pleasure can serve cognition, productivity and health, but simultaneously promotes addiction and other negative behaviors. It is a complex neurobiological phenomenon, relying on reward circuitry or limbic activity. These processes involve dopaminergic signaling. Moreover, nicotine, cocaine and alcohol appear to exert their pleasure providing action via endogenous morphinergic mechanisms. Natural rewarding activities are necessary for survival and appetitive motivation, usually governing beneficial biological behaviors like eating, sex and reproduction. Social contacts can further facilitate the positive effects exerted by pleasurable experiences. However, artificial stimulants can be detrimental, since flexibility and normal control of behavior are deteriorated. Additionally, addictive drugs are capable of directly acting on reward pathways, now, in part, via endogenous morphine processes.
authors.affiliation: Neuroscience Research Institute, State University of New York College at Old Westbury, Old Westbury, NY 11568, USA. gstefano@sunynri.org
authors.forename: George B
authors.initials: GB
authors.lastname: Stefano
authors.forename: Enrica
authors.initials: E
authors.lastname: Bianchi
authors.forename: Massimo
authors.initials: M
authors.lastname: Guarna
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Fricchione
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.forename: Patrick
authors.initials: P
authors.lastname: Cadet
authors.forename: Kirk J
authors.initials: KJ
authors.lastname: Mantione
authors.forename: Federico M
authors.initials: FM
authors.lastname: Casares
authors.forename: Richard M
authors.initials: RM
authors.lastname: Kream
authors.forename: Tobias
authors.initials: T
authors.lastname: Esch
mesh_terms: D000438:Alcohols / Q000378:metabolism*; D000818:Animals; D003042:Cocaine / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D009020:Morphine / Q000378:metabolism*; D009538:Nicotine / Q000378:metabolism*; D012201:Reward; D015398:Signal Transduction
chemical_list: D000438:Alcohols; D009538:Nicotine; D009020:Morphine; D003042:Cocaine