title: Prolonged rewarding stimulation of the rat medial forebrain bundle: neurochemical and behavioral consequences.
abstract: Extracellular dopamine levels were measured in the rat nucleus accumbens by means of in vivo microdialysis. Delivery of rewarding medial forebrain bundle stimulation at a low rate (5 trains/min) produced a sustained elevation of dopamine levels, regardless of whether train onset was predictable. When the rate of train delivery was increased to 40 trains/min, dopamine levels rose rapidly during the first 40 min but then declined toward the baseline range. The rewarding impact of the stimulation was reduced following prior delivery of stimulation at the high, but not the low, rate. These results support the idea that dopamine tone plays an enabling role in brain stimulation reward and is elevated similarly by predictable and unpredictable stimulation.
authors.affiliation: Center for Studies in Behavioural Neurobiology, Concordia University, Montreal, PQ, Canada.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Hernandez
authors.forename: Selma
authors.initials: S
authors.lastname: Hamdani
authors.forename: Heshmat
authors.initials: H
authors.lastname: Rajabi
authors.forename: Kent
authors.initials: K
authors.lastname: Conover
authors.forename: Jane
authors.initials: J
authors.lastname: Stewart
authors.forename: Andreas
authors.initials: A
authors.lastname: Arvanitogiannis
authors.forename: Peter
authors.initials: P
authors.lastname: Shizgal
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology* / Q000528:radiation effects; D001923:Brain Chemistry / Q000528:radiation effects; D004298:Dopamine / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods; D008297:Male; D008474:Medial Forebrain Bundle / Q000502:physiology* / Q000528:radiation effects; D017551:Microdialysis / Q000379:methods; D008954:Models, Biological; D009714:Nucleus Accumbens / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D012055:Reinforcement Schedule; D012201:Reward; D012646:Self Administration / Q000379:methods; D013997:Time Factors
chemical_list: D004298:Dopamine