Depolarization

Definition

Depolarization is the process by which a neuron's membrane potential becomes less negative, moving closer to zero. This change is crucial for the initiation and transmission of electrical signals in neurons.

5 Must Know Facts For Your Next Test

1. Depolarization occurs when sodium ions (Na+) flow into the neuron through voltage-gated sodium channels.
2. It is a key phase in the generation of an action potential.
3. Depolarization must reach a certain threshold potential to trigger an action potential.
4. The rapid influx of Na+ during depolarization causes the inside of the neuron to become positively charged relative to the outside.
5. Following depolarization, repolarization occurs to restore the neuron's resting membrane potential.

Review Questions

• What ions are primarily responsible for causing depolarization in neurons?
• Why is reaching the threshold potential important during depolarization?
• What happens to the charge inside the neuron during depolarization?

Related terms

Action Potential: A rapid rise and subsequent fall in membrane potential that propagates along the axon of a neuron.

Repolarization:

The process by which a cell restores its resting membrane potential following depolarization.

Sodium-Potassium Pump: A protein that helps maintain resting membrane potential by pumping sodium out and potassium into the cell.