title: Route of nicotine administration influences in vivo dopamine neuron activity: habituation, needle injection, and cannula infusion.
abstract: Mesolimbic dopamine (DA) systems play a critical role in tobacco addiction driven by nicotine. Nicotine activates midbrain DA neurons and, consequently, elevates DA concentrations in targets, especially in the nucleus accumbens (NAc) of the ventral striatum. The route of drug administration influences the impact of addictive drugs. Here, we examine whether the nature of the administration alters DA neuron activity and DA concentrations in the NAc. Using unhabituated naïve freely moving rats, microdialysis measurements showed that nicotine administered via needle injection caused greater DA release in the NAc than the same dose administered via an implanted chronic cannula. After habituation to the needle injections, however, there was no significant difference in DA signaling between the needle and cannula routes of administration. Consistent with these microdialysis results after habituation, our in vivo tetrode unit recordings showed no significant difference in midbrain DA neuron activity in response to nicotine delivered by needle or cannula as long as predictive cues were avoided
authors.affiliation: Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030-3498, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Dong
authors.forename: Tianxiang
authors.initials: T
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: William M
authors.initials: WM
authors.lastname: Doyon
authors.forename: William
authors.initials: W
authors.lastname: Doyon
authors.forename: John A
authors.initials: JA
authors.lastname: Dani
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology*; D002404:Catheterization; D003463:Cues; D004298:Dopamine / Q000378:metabolism*; D004333:Drug Administration Routes; D045604:Extracellular Fluid / Q000187:drug effects / Q000378:metabolism; D007260:Infusion Pumps; D007267:Injections; D008297:Male; D017551:Microdialysis; D009339:Needles; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D019966:Substance-Related Disorders / Q000378:metabolism / Q000503:physiopathology*; D014029:Tobacco Use Disorder / Q000378:metabolism / Q000503:physiopathology*; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine; D004298:Dopamine