( PCP ( ( ( can also ) ( ( affect ( ( some types ) ( of ( opioid receptors ) ) ) ) ( in ( the brain ) ) ) ) . ) )
(ROOT (S (NP (NNP PCP)) (VP (MD can) (ADVP (RB also)) (VP (VB affect) (NP (NP (DT some) (NNS types)) (PP (IN of) (NP (JJ opioid) (NNS receptors)))) (PP (IN in) (NP (DT the) (NN brain))))) (. .)))
PCP can also affect some types of opioid receptors in the brain.
(ROOT (S (NP (NNP Addiction)) (VP (VBZ affects) (NP (NP (DT the) (JJ dopamine) (NNS receptors)) (PP (IN within) (NP (DT the) (NN brain))))) (. .)))