title: Thalamo-cortical dysfunction in cocaine abusers: implications in attention and perception.
abstract: Cocaine affects sensory perception and attention, but little is known about the neural substrates underlying these effects in the human brain. We used functional magnetic resonance imaging (fMRI) and a sustained visuospatial attention task to assess if the visual attention network is dysfunctional in cocaine abusers (n=14) compared to age-, gender-, and education-matched controls (n=14). Compared with controls, cocaine abusers showed (1) hypo-activation of the thalamus, which may reflect noradrenergic and/or dopaminergic deficits; (2) hyper-activation in occipital and prefrontal cortices, which may reflect increased visual cortical processing to compensate for inefficient visual thalamic processing; and (3) larger deactivation of parietal and frontal regions possibly to support the larger hemodynamic supply to the hyper-activated brain regions. These findings provide evidence of abnormalities in thalamo-cortical responses in cocaine abusers that are likely to contribute to the impairments in sensory processing and in attention. The development of therapies that diminish these thalamo-cortical deficits could improve the treatment of cocaine addiction.
authors.affiliation: Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA. tomasi@bnl.gov
authors.forename: Dardo
authors.initials: D
authors.lastname: Tomasi
authors.forename: Rita Z
authors.initials: RZ
authors.lastname: Goldstein
authors.forename: Frank
authors.initials: F
authors.lastname: Telang
authors.forename: Thomas
authors.initials: T
authors.lastname: Maloney
authors.forename: Nelly
authors.initials: N
authors.lastname: Alia-Klein
authors.forename: Elisabeth C
authors.initials: EC
authors.lastname: Caparelli
authors.forename: Nora D
authors.initials: ND
authors.lastname: Volkow
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D019970:Cocaine-Related Disorders / Q000453:epidemiology* / Q000503:physiopathology* / Q000652:urine; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010468:Perceptual Disorders / Q000175:diagnosis / Q000453:epidemiology*; D013788:Thalamus / Q000503:physiopathology*; D014793:Visual Cortex / Q000503:physiopathology; D014796:Visual Perception