Generator Potentials:

Generator potentials, also called graded or receptor potentials, are the initial electrical signal from a converted (transduced) sensory stimuli (light, sound, pressure) received by a sensory receptor. The signal is a “graded” (weak-to-strong) in intensity. If the stimulus is graded as strong enough, the generator potential directly “generates” appropriate action (action potential) — which travels along the neuron’s axon to convey its signal to the central nervous system (CNS). Triggered action potentials are “all-or-none,” while generator potentials can vary in strength depending on the graded intensity. Generator potentials are also on cell membranes, where an excitatory or inhibitory synapse has taken place.