Excitatory synapses

• A neurotransmitter is stored in the synaptic vesicles in the presynaptic neurone. When an action potential reaches the synaptic knob, the membranes of the vesicles fuse with the pre-synaptic membrane to release the neurotransmitter.
• When released, the neurotransmitters in an excitatory neurone diffuse across the synaptic cleft to bind to specific receptor proteins on the post-synaptic neurone.
• The neurotransmitter binds to the receptor proteins, leading to a new action potential being generated in the postsynaptic neurone. These synapses are known as excitatory synapses.