title: Cannabinoid self-administration increases dopamine release in the nucleus accumbens.
abstract: In the present study, dopamine release was monitored during cannabinoid self-administration in rats to achieve a detailed understanding of the way in which dopamine mediates the reinforcing effects of cannabinoids. Extracellular dopamine levels were measured in the shell of the nucleus accumbens of either Lister Hooded or Long Evans rats trained to self-administer the cannabinoid CB1 receptor agonist WIN 55,212-2. A significant relationship between extracellular dopamine levels and bar-pressing rates was observed in both strains, as the dopamine content appreciably increased in respect to basal values during cannabinoid intake. Importantly, dopamine was not modified when trained rats were shifted to vehicle self-administration suggesting that an enhanced activity of the mesolimbic dopamine pathway underlies cannabinoid-taking behaviour.
authors.affiliation: Department of Neuroscience, University of Cagliari, Monserrato-Cagliari, Italy. pfadda@unica.it
authors.forename: Paola
authors.initials: P
authors.lastname: Fadda
authors.forename: Maria
authors.initials: M
authors.lastname: Scherma
authors.forename: Maria Sabrina
authors.initials: MS
authors.lastname: Spano
authors.forename: Paola
authors.initials: P
authors.lastname: Salis
authors.forename: Valeria
authors.initials: V
authors.lastname: Melis
authors.forename: Liana
authors.initials: L
authors.lastname: Fattore
authors.forename: Walter
authors.initials: W
authors.lastname: Fratta
mesh_terms: D000700:Analgesics / Q000008:administration & dosage; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D048588:Benzoxazines; D002186:Cannabinoids / Q000008:administration & dosage*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D009025:Morpholines / Q000008:administration & dosage; D009281:Naphthalenes / Q000008:administration & dosage; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D012646:Self Administration / Q000379:methods; D013997:Time Factors
chemical_list: D000700:Analgesics; D048588:Benzoxazines; D002186:Cannabinoids; D009025:Morpholines; D009281:Naphthalenes; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D004298:Dopamine