depolarization

1. A relative reduction in magnitude of polarization; in nerve cells, d. may result from an increase in the permeability of the cell membrane to sodium ions. 2. The destruction, neutralization, or change in direction of polarity.

- dendritic d. the loss of a negative charge in the dendrites of a nerve cell.

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de·po·lar·iza·tion or Brit de·po·lar·isa·tion (.)dē-.pō-lə-rə-'zā-shən n loss of polarization esp loss of the difference in charge between the inside and outside of the plasma membrane of a muscle or nerve cell due to a change in permeability and migration of sodium ions to the interior

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n.

the sudden surge of charged particles across the membrane of a nerve cell or a muscle cell that accompanies a physicochemical change in the membrane and cancels out, or reverses, its resting potential to produce an action potential. The passage of a nerve impulse is a rapid wave of depolarization along the membrane of a nerve fibre.

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de·po·lar·iza·tion (de-po″lər-ĭ-zaґshən) [de- + polarization] 1. the process or act of neutralizing polarity. 2. in electrophysiology, the reversal of the resting potential in excitable cell membranes when stimulated, i.e., the tendency of the cell membrane potential to become positive with respect to the potential outside the cell. See also sodium channel, under channel.