Beoordeeld potentieel

The graded potential is a short-lived, localized change in the membrane potential of a neuron.

A graded potential occurs in response to a stimulus, causing the ligand-gated or mechanically-gated ion channels to open or close.

The resulting flow of ions makes the cytoplasmic side of the membrane less negative or depolarized. In contrast, a net inflow of negative ions can make the interior more negative or hyperpolarize.

Graded potentials are so named because the number of ion channels involved and how long they remain open is directly proportional to the strength of the stimulus.

These potentials are decremental in nature. The current, carried by ions, flows along the plasma membrane, depolarizing the adjacent regions.

As some of these ions are lost through the leak channels on the membrane, the potential gradually diminishes in strength as it moves further from the stimulation site.

But, multiple graded potentials can summate to generate a potential with increased strength and duration.

If the resulting depolarization reaches a certain threshold, an action potential is triggered, which can transmit signals along the axon over long distances.