( There ( ( are ( ( two types ) ( of ( postsynaptic ( dopamine receptors ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD two) (NNS types)) (PP (IN of) (NP (JJ postsynaptic) (NN dopamine) (NNS receptors))))) (. .)))
There are two types of postsynaptic dopamine receptors.
(ROOT (S (NP (NNP Addiction)) (VP (VBZ affects) (NP (NP (DT the) (JJ dopamine) (NNS receptors)) (PP (IN within) (NP (DT the) (NN brain))))) (. .)))