( ( ( The synthesis ) ( of ( ( catecholamines ( -LRB- ( ( ( ( ( e.g. , ) dopamine ) , ) norepinephrine ) -RRB- ) ) ) ( in ( the brain ) ) ) ) ) ( also ( ( varies ( with ( ( the availability ) ( of ( the ( precursor ( amino ( acid L-tyrosine ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (NP (DT The) (NN synthesis)) (PP (IN of) (NP (NP (NP (NNS catecholamines)) (PRN (-LRB- -LRB-) (NP (NNP e.g.)) (, ,) (NP (NN dopamine)) (, ,) (NP (NN norepinephrine)) (-RRB- -RRB-))) (PP (IN in) (NP (DT the) (NN brain)))))) (ADVP (RB also)) (VP (VBZ varies) (PP (IN with) (NP (NP (DT the) (NN availability)) (PP (IN of) (NP (DT the) (NN precursor) (JJ amino) (NN acid) (NN L-tyrosine)))))) (. .)))
The synthesis of catecholamines (e.g., dopamine, norepinephrine) in the brain also varies with the availability of the precursor amino acid L-tyrosine.
(ROOT (S (NP (NNS Catecholamines)) (VP (VBP are) (NP (NP (DT a) (NN class)) (PP (IN of) (NP (JJ amine) (NNS hormones))) (SBAR (WHNP (WHNP (DT that)) (NP (WRB when) (JJ synthesised))) (S (VP (VBP form) (NP (DT the) (JJ amino) (NN acid) (NN tyrosine))))))) (. .)))