( ( When ( ( a ( signalling cell ) ) ( sends ( a message ) ) ) ) ( , ( ( an ( electrical impulse ) ) ( ( ( travels down ) ( ( a process ) ( leading ( to ( release ( of ( ( ( ( neurotransmitters , ) ( nerve ( signaling chemicals ) ) ) , ) ( near ( the ( receiving cell ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT a) (VBG signalling) (NN cell)) (VP (VBZ sends) (NP (DT a) (NN message))))) (, ,) (NP (DT an) (JJ electrical) (NN impulse)) (VP (VBZ travels) (PRT (RP down)) (NP (NP (DT a) (NN process)) (VP (VBG leading) (S (VP (TO to) (VP (VB release) (PP (IN of) (NP (NP (NP (NNS neurotransmitters)) (, ,) (NP (NN nerve) (NN signaling) (NNS chemicals)) (, ,)) (PP (IN near) (NP (DT the) (NN receiving) (NN cell))))))))))) (. .)))
When a signalling cell sends a message, an electrical impulse travels down a process leading to release of neurotransmitters, nerve signaling chemicals, near the receiving cell.
(ROOT (S (NP (NP (DT An) (JJ electrical) (NN signal)) (PP (IN along) (NP (DT a) (NN nerve) (NN cell)))) (VP (VBZ triggers) (NP (NP (DT the) (NN secretion)) (PP (IN of) (NP (NN neurotransmitter) (NNS molecules))))) (. .)))