Graded Potentials - occur in dendrites, cell bodies or axon terminals. Graded potential refers to the post synaptic electrical impulse. Called ‘graded’ because their size or amplitude is directly proportional to the strength of the triggering event. i.e. a large stimulus leads to the generation of a strong graded response, and a small stimulus leads to the generation of a weak graded response.
A depolarising graded potential is known as an excitatory postsynaptic potential (EPSP).
A hyperpolarising graded potential is known as an inhibitory postsynaptic potential (IPSP).
If graded potentials reaching the axon hillock depolarise the membrane to the threshold voltage, an Action potential is initiated.