regulation of membrane potential

Definition

Target type: biologicalprocess

Any process that modulates the establishment or extent of a membrane potential, the electric potential existing across any membrane arising from charges in the membrane itself and from the charges present in the media on either side of the membrane. [GOC:jl, GOC:mtg_cardio, GOC:tb, ISBN:0198506732]

Membrane potential, the electrical potential difference across the plasma membrane of a cell, is crucial for various cellular functions, including nerve impulse transmission, muscle contraction, and nutrient transport. It is dynamically regulated by the movement of ions across the membrane, primarily through ion channels and pumps.

The resting membrane potential, typically negative inside the cell, is established by the unequal distribution of ions across the membrane. The sodium-potassium pump actively transports three sodium ions (Na+) out of the cell for every two potassium ions (K+) pumped in, creating a concentration gradient and a negative charge inside. This pump requires ATP for operation.

Ion channels, selective for specific ions, contribute to the regulation of membrane potential by allowing passive movement of ions down their electrochemical gradients. Leak channels are always open, while gated channels open or close in response to specific stimuli.

The key players in membrane potential regulation are:

* **Sodium channels:** Open during depolarization, allowing Na+ influx and further depolarizing the membrane.
* **Potassium channels:** Open during repolarization, allowing K+ efflux and returning the membrane potential toward its resting state.
* **Calcium channels:** Important for various cellular processes, including neurotransmitter release and muscle contraction.
* **Chloride channels:** Contribute to maintaining the resting membrane potential and regulating cell volume.

Changes in membrane potential are referred to as depolarization (becoming more positive) or hyperpolarization (becoming more negative). These changes can be triggered by various stimuli, including neurotransmitters, hormones, and mechanical stimulation.

The regulation of membrane potential involves complex interactions between ion channels, pumps, and intracellular signaling pathways. It ensures proper cell function and communication, playing a vital role in maintaining homeostasis and responding to external stimuli.'
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Proteins (48)

Compounds (909)