Quicktime movie of the action potential and neurotransmitters crossing the synapse (with awesome music by They Might Be Giants). It may be helpful to move through the movie frame by frame to study the sequence of events and match it up to the lecture and slides. Note that at the end of the sequence just before it repeats, an enzyme labeled AChE (for acetylcholinesterase) appears, to break down any neurotransmitter (apparently acetylcholine in this case) that remains in the synapse after the signal has been sent.