Figure 3.

Adenosine A_2AR activation inhibits the nicotine-induced [³H]DA release from rat striatal synaptosomes. (A) Time course and (B) bar graph displaying the averaged release of [³H]DA induced by various concentrations of nicotine alone or in the presence of A_2AR agonist, CGS (10–100 nM). The co-administration of CGS and nicotine occurred as indicated by the horizontal bar in (A). Data are mean ± SEM of 6–18 experiments performed in duplicate. *P < 0.05, **P < 0.01 and ***P < 0.001 versus 0 FR% (i.e. no change in baseline); ^$P < 0.05 and ^$$P < 0.01 between nicotine alone (green bar) and nicotine with CGS; n.s., not significant.