Portal de Periódicos da CAPES

Association of Low Striatal Dopamine D 2 Receptor Availability With Nicotine Dependence Similar to That Seen With Other Drugs of Abuse

2008; American Psychiatric Association; Volume: 165; Issue: 4 Linguagem: Inglês

10.1176/appi.ajp.2007.07020352

1535-7228

Christoph Fehr, Igor Yakushev, Nina Hohmann, Hans‐Georg Buchholz, Christian Landvogt, Hanna Deckers, Alexandra Eberhardt, Marie Kläger, Michael N. Smolka, Armin Scheurich, Thomas F. Dielentheis, Lutz Schmidt, Frank Rösch, Peter Bartenstein, Gerhard Gründer, Mathias Schreckenberger,

Smoking Behavior and Cessation

All drugs of abuse induce a phasic dopamine release within the striatum that does not undergo habituation. Prolonged substance consumption impairs the natural function of the mesolimbic dopamine system, as shown by a decrease in the availability of striatal dopamine 2 (D(2)) receptors in patients suffering from cocaine, heroin, amphetamine, and alcohol dependence. However, it is unclear whether similar changes can also be observed in heavy-smoking nicotine-dependent smokers.In vivo D(2)/D(3) receptor availability was determined with [ (18)F]fallypride positron emission tomography in 17 heavy-smoking nicotine-dependent subjects and in 21 age-matched never-smoking comparison subjects. The smokers were scanned twice: first, during a period of usual consumption and second, 24 hours after smoking cessation.Independent of the withdrawal status, the nicotine-dependent smokers displayed significantly less availability of D(2)/D(3) receptors within the bilateral putamen functionally covering parts of the dorsal striatum, as compared to the never-smoking subjects. Nicotine craving under the consumption condition correlated positively with D(2)/D(3) receptor availability within the ventral striatum but negatively with D(2)/D(3) receptor availability within the anterior cingulate and inferior temporal cortex.Similar to other types of substance abuse, nicotine dependence is associated with low availability of dorsal striatal D(2)/D(3) receptors. In contrast to previous findings on abstinent alcohol-dependent patients, nicotine craving seems to be maintained by a region-specific shift in D(2)/D(3) receptor availabilities, with higher availability within the ventral striatum but lower availability within the anterior cingulate and inferior temporal cortex.