Receptor potential
The receptor potential ( Latin: receptor , `` pick-up '', `` receiver '' and the Latin `` potentialis '', `` according to ability '', `` active effect '') - generator potential is often used as a synonym - describes a membrane- electrical response of the receptors to a stimulus .
Some authors differentiate between receptor potential and generator potential: A depolarization in the membrane of a sensory neuron is called generator potential . A receptor potential, on the other hand, is created in the membrane of a receptor cell .
The receptor potential is a direct result of the transduction process , the conversion of stimulus energy into the body's own excitation. The course of the receptor potential when using a standardized stimulus (e.g. the jump stimulus) is different for the different receptors. A potential composed of a proportional and differential component (see differential quotient sensitivity , proportional behavior ) is typical .
The receptor potential is usually a result of the opening of sodium channels (the release of sodium ions is the actual excitation) in the receptor cell. An exception is the receptor potential of the photoreceptors , where the actual receptor potential is a hyperpolarization triggered by closing the sodium channels .
The receptor potential does not follow the all-or-nothing law ; that is, it gradually grows with the strength of the stimulus. When a certain threshold value ( threshold potential ) is reached, an action potential occurs , which (like almost all action potentials) follows the all-or-nothing law. The receptor potential also has no refractory period .
See also
Individual evidence
- ^ Christopher D. Moyes, Patricia M. Schulte: Tierphysiologie . Pearson Studium, Munich 2008, ISBN 978-3-8273-7270-3 , pp. 279 (English: Principles of Animal Physiology . Translated by Monika Niehaus , Sebastian Vogel).