--%>

Depolarization of neuronal plasma membrane

How is the depolarization of neuronal plasma membrane produced? How does the cell return to its original rest?

E

Expert

Verified

When the neuron gets a stimulus by the binding of neurotransmitters to particular receptors sodium channels open and the permeability of plasma membrane in the postsynaptic region is changed. Sodium ions then go in the cell causing lowering (less negative) of membrane potential. If this reduction of membrane potential reaches a level called excitation threshold or threshold potential, about –50 mV, action potential is generated, that is, the depolarization intensifies till reaching its maximum level and depolarization current is transmitted along the remaining length of neuronal membrane.

If excitation threshold is reached voltage-dependent sodium channels in membrane open allowing more sodium ions to enter cell in favor of the concentration gradient and an estimated –35 mV level of positive polarization of the membrane is accomplished. The voltage-dependent sodium channels then close and more voltage dependent potassium channels open. Potassium ions then exit the cell in favor of the concentration gradient and the potential difference of the membrane diminishes, a process named as repolarization.

The action potential triggers the same electrical phenomenon in neighboring areas of plasma membrane and impulse is therefore transmitted from dendrites to terminal region of the axon.

   Related Questions in Biology

  • Q : Illustrations of secretory cells What

    What are some illustrations of secretory cells?

  • Q : How much must I nourish my pet How much

    How much must I nourish my pet?

  • Q : Arthropods

    According to examples of representing beings, how are arthropods characterized, fundamental morphology, kind of symmetry, germ layers and coelom, respiratory system, digestive system, excretory system, circulatory system, nervous system and kinds of reproduction?

  • Q : Categorization of membranes according

    Relating to their permeability how are membranes categorized?

  • Q : What is Direct Response Marketing

    Direct Response Marketing: It is a form of marketing that elicits an exact, measured response resulting from direct response to a marketer of a consumer. Direct response marketing assists the delivery of a call to action and outcome through direct or

  • Q : Saturation or unsaturation of fats and

    What is the meaning of saturation or unsaturation of fats and oils?

  • Q : Explain New Product Introduction New

    New Product Introduction: Product introduction is a business process by that a new product is debuted, launched or published into the market for usual users and or businesses. The product introduction process is ex

  • Q : What is Cyclosis Cyclosis : Cyclosis is

    Cyclosis: Cyclosis is a kind of internal cell movement in which an oriented flow of circulating material is formed and maintained in cytoplasm by the action of microfilaments. Cyclosis is much easily detected in plant cells.

  • Q : First entirely terrestrial class Which

    Which vertebrate class is considered as the first entirely terrestrial?

  • Q : Organizational change How did the

    How did the article improve your understanding of organizational change?