Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Voltage-gated channels

Description

This lecture covers the cellular mechanisms of brain function related to voltage-gated ion channels, focusing on their protein structure, voltage-gating mechanisms, open probability, conductance, and the role of Na+ and K+ channels. It also discusses the impact of membrane potential on channel behavior.

In MOOC

Cellular Mechanisms of Brain Function

Official source

Quiz

Ontological neighbourhood

Biology

Cell biology: Neurotransmission

Related concepts (32)

Sodium channel

Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's membrane. They belong to the superfamily of cation channels. They are classified into 2 types: In excitable cells such as neurons, myocytes, and certain types of glia, sodium channels are responsible for the rising phase of action potentials. These channels go through three different states called resting, active and inactive states.

Voltage-gated ion channel

Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the channel. The membrane potential alters the conformation of the channel proteins, regulating their opening and closing. Cell membranes are generally impermeable to ions, thus they must diffuse through the membrane through transmembrane protein channels. They have a crucial role in excitable cells such as neuronal and muscle tissues, allowing a rapid and co-ordinated depolarization in response to triggering voltage change.

Voltage-gated potassium channel

Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state. Alpha subunits form the actual conductance pore. Based on sequence homology of the hydrophobic transmembrane cores, the alpha subunits of voltage-gated potassium channels are grouped into 12 classes. These are labeled Kvα1-12.

Ion channel

Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions across secretory and epithelial cells, and regulating cell volume. Ion channels are present in the membranes of all cells. Ion channels are one of the two classes of ionophoric proteins, the other being ion transporters.

Voltage-gated calcium channel

Voltage-gated calcium channels (VGCCs), also known as voltage-dependent calcium channels (VDCCs), are a group of voltage-gated ion channels found in the membrane of excitable cells (e.g., muscle, glial cells, neurons, etc.) with a permeability to the calcium ion Ca2+. These channels are slightly permeable to sodium ions, so they are also called Ca2+-Na+ channels, but their permeability to calcium is about 1000-fold greater than to sodium under normal physiological conditions.

Related lectures (32)

Action Potentials and Electrical Excitability

Explores the generation and propagation of action potentials in neurons, including the historical significance of Hodgkin & Huxley's work.

Electricity in Cells

Explores the physical basis of signal propagation in neurons, focusing on membrane potential setup and ion channels.

Resting Membrane Potential

Discusses resting membrane potential, ion channels, and the Na+/K+ pump.

Cellular Mechanisms of Brain Function

Explores cellular mechanisms of brain function, focusing on ion channels and action potentials.

Cellular Mechanisms of Brain Function

Explores the electrical properties of cell membranes and their role in brain function.

Related concepts (32)

Sodium channel

Voltage-gated ion channel

Voltage-gated potassium channel

Ion channel

Voltage-gated calcium channel