What is the process of neurotransmitters crossing the synapse?

1. An action potential in the pre-synaptic cell triggers synaptic vesicles to move towards the cell membrane. 2. This is followed by a fusion of the two membranes. 3. Neurotransmitter molecules are then released. 4. Neurotransmitter then flows into the synaptic cleft where it is available to bind to receptors on the post-synaptic membrane.