title: Effects of nicotine withdrawal on verbal working memory and associated brain response.
abstract: Previous literature has reported effects of nicotine withdrawal on brain function during cognitive tasks such as verbal working memory (VWM). Mechanisms of these withdrawal effects have not been clearly identified. Functional neuroimaging offers an objective method to examine brain mechanisms associated with observable behavior and subjective reports. To investigate these mechanisms, 12 smokers were administered a 2-Back VWM challenge during two functional magnetic resonance imaging sessions. Participants abstained from smoking prior to both sessions; however, they applied a nicotine patch before one session and a placebo patch prior to the other. Among regions that exhibited a significant response to the 2-Back during either session, withdrawal was associated with significantly greater deactivation in left and right temporal poles and left medial frontal gyrus. The magnitude of task-related activation showed a significant inverse relationship to craving in the majority of regions during placebo administration. Also, individual brain responses varied more during placebo, suggesting inefficient neural processing. Results suggest that differences in brain response to a VWM challenge during abstinence may be attributed to increased craving. Further deactivation of regions associated with the default network (medial frontal and anterior temporal clusters) during the placebo condition suggests further suspension of default activity, possibly to compensate for inefficient neural processing.
authors.affiliation: Department of Psychiatry, Alpert Medical School of Brown University, Providence, RI 02906, United States. Lawrence_Sweet@Brown.edu
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Sweet
authors.forename: Richard C
authors.initials: RC
authors.lastname: Mulligan
authors.forename: Colleen E
authors.initials: CE
authors.lastname: Finnerty
authors.forename: Beth A
authors.initials: BA
authors.lastname: Jerskey
authors.forename: Sean P
authors.initials: SP
authors.lastname: David
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Cohen
authors.forename: Raymond S
authors.initials: RS
authors.lastname: Niaura
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D009538:Nicotine / Q000009:adverse effects*; D018722:Nicotinic Agonists / Q000009:adverse effects*; D013375:Substance Withdrawal Syndrome / Q000473:pathology* / Q000503:physiopathology / Q000523:psychology; D014706:Verbal Learning / Q000187:drug effects / Q000502:physiology*
chemical_list: D018722:Nicotinic Agonists; D009538:Nicotine