Question Students need to contribute eight substantive posts in this discussion by the due date indicated. The substantive posts can be any combination of responses and replies. Here are the topics! Explain the action potential, including: What events happen to form an action potential? How does the action potential move down the axon? How does the action potential trigger the release of neurotransmitters at the synapse? Why are neurotransmitters important for brain function? Describe how neurotransmitters function in the synapse and brain.