Excitability

noun

1. The quality of being excitable; readiness or proneness to be provoked or moved into action; the quality of being easily agitated; nervousness.
2. In physiology, irritability.
3. The quality of being readily excited; proneness to be affected by exciting causes.
4. The property manifested by living organisms, and the elements and tissues of which they are constituted, of responding to the action of stimulants; irritability.

   "nervous excitability"

5. The state of being excitable