Postsynaptic potentials are changes in the
membrane potential of the postsynaptic terminal of a chemical synapse. Postsynaptic potentials are
graded potentials, and should not be confused with
action potentials although their function is to initiate or inhibit action potentials. They are caused by the presynaptic neuron releasing
neurotransmitters from the terminal bouton at the end of an
axon into the
synaptic cleft. The neurotransmitters bind to
receptors on the postsynaptic terminal, which may be a
neuron or a
muscle cell in the case of a
neuromuscular junction. These are collectively referred to as postsynaptic receptors, since they are on the membrane of the postsynaptic cell. . .