( ( The ( activated ( reticular formation ) ) ) ( then ( ( ( arouses ( the ( cerebral cortex ) ) ) ( by ( means ( of ( two pathways ) ) ) ) ) . ) ) )
(ROOT (S (NP (DT The) (VBN activated) (NN reticular) (NN formation)) (ADVP (RB then)) (VP (VBZ arouses) (NP (DT the) (JJ cerebral) (NN cortex)) (PP (IN by) (NP (NP (NNS means)) (PP (IN of) (NP (CD two) (NNS pathways)))))) (. .)))
The activated reticular formation then arouses the cerebral cortex by means of two pathways.
(ROOT (S (NP (JJ Reticular) (NN formation)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN of) (NP (NP (DT the) (NN formation)) (SBAR (WHNP (WDT that)) (S (VP (VBZ regulates) (NP (NN sleep) (CC and) (NN arousal))))))))) (. .)))