Lecture

Voltage-gating kinetics: Na+ and K+ channels

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Description

This lecture covers the voltage-gating kinetics of Na+ and K+ channels, discussing the rapid opening and inactivation of Na+ channels in response to depolarization, as well as the slower activation of K+ channels without inactivation. It also explores the recovery from inactivation, K+ channel diversity with over 80 genes, and membrane potential dynamics.

In MOOC

Cellular Mechanisms of Brain Function

The function of the brain is to govern behavior, and the aim of this course is to causally link biophysical mechanisms with simple behaviors studied in mice. The brain processes information through the concerted activity of many neurons, which communicate with each other through synapses organised in highly dynamic networks. The first goal of the course is to gain a detailed understanding of the structure and function of the fundamental building blocks of the mammalian brain, its synapses and neurons (Weeks

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Biology

Cell biology: Neurotransmission

Related concepts (13)

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.

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 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.

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.

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