I just learned that "action potential is a short-lasting event" (wiki) If someone is experiencing an emotion of sadness, is that same action potential keeps firing many times back to back or can it actually be a possibility that an action potential lasts for a "very long time". I am guessing the prior is true since neurons' neurotransmitters can't just keep a neural spike "alive". Once they cross the gap, they are on the other side, and their job is done until the get back. Or am I thinking about this the wrong way? Or maybe this is a different type of a spike and neurotransmitter functioning? Like for example, a hormone release of neurotransmitters by endocrine cells, which creates a specific "longer lasting" emotion?