( ( ( ( Zyban , ) ( a ( prescription drug ) ) ) , ) ( ( works ( on ( ( the ( serotonin receptors ) ) ( in ( ( the brain ) ( that ( affect ( nicotine addiction ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Zyban)) (, ,) (NP (DT a) (NN prescription) (NN drug)) (, ,)) (VP (VBZ works) (PP (IN on) (NP (NP (DT the) (NN serotonin) (NNS receptors)) (PP (IN in) (NP (NP (DT the) (NN brain)) (SBAR (WHNP (WDT that)) (S (VP (VBP affect) (NP (NN nicotine) (NN addiction)))))))))) (. .)))
Zyban, a prescription drug, works on the serotonin receptors in the brain that affect nicotine addiction.
(ROOT (S (NP (NNP Addiction)) (VP (VBZ affects) (NP (NP (DT the) (JJ dopamine) (NNS receptors)) (PP (IN within) (NP (DT the) (NN brain))))) (. .)))