Neurotransmitters bind to ionotropic receptors on postsynaptic neurons, either causing their opening or closing. The variations in the quantities of neurotransmitters released from the presynaptic neuron may play a role in regulating the effectiveness of synaptic transmission. In fact, the concentration of cytoplasmic calcium is involved in regulating the release of neurotransmitters from presynaptic neurons.
The chemical transmission involves several sequential processes:
# Synthesizing neurotransmitters within the presynaptic neuron.
# Loading the neurotransmitters into secretory vesicles.
# Controlling the release of neurotransmitters into the synaptic cleft.
# Binding of neurotransmitters to postsynaptic receptors.
# Ceasing the activity of the released neurotransmitters.