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ion channel

a group of proteins forming a channel that spans a cell membrane, allowing the passage of ions between the extracellular environment and the cytoplasm of the cell. Ion channels are selective; allow passage of ions of a particular chemical nature, size, or electrostatic charge; and may be ungated (i.e., always open) or gated, opening and closing in response to chemical, electrical, or mechanical signals (see ligand-gated ion channel; voltage-gated ion channel). Ion channels are important in the transmission of neural signals between neurons at a synapse. The opening of sodium channels in the membrane of a postsynaptic neuron permits an influx of sodium ions (Na+) into the neuron, which produces an excitatory postsynaptic potential. The opening of potassium channels or chloride channels allows potassium ions (K+) to leave the postsynaptic neuron or chloride ions (Cl) to enter it, either of which produces an inhibitory postsynaptic potential. See also calcium channel.

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Psychology term of the day

March 7th 2025

integrative learning

integrative learning

the process of learning tasks that involve simultaneous or successive functioning of several modalities, as in reading and writing.