WordNet sense 1 (of or relating to the nervous system):

neural

WordNet sense 2 (causing or fraught with or showing anxiety):

anxious, queasy, uneasy, unquiet

WordNet sense 3 (characterized by or indicative of distress or affliction or danger or need):

troubled

WordNet sense 4 (in or of a state of physical or nervous tension):

tense

WordNet sense 5 (excited in anticipation):

aflutter

WordNet sense 6 (unpredictably excitable (especially of horses)):

flighty, skittish, spooky

WordNet sense 7 (easily excited):

excitable