channel

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channel

 [chan´el]
a passage, cut, or groove through which something can pass or flow across a solid structure.
calcium channel (calcium-sodium channel) a slow voltage-gated channel very permeable to calcium ions and slightly permeable to sodium ions, existing in three subtypes designated L, M, and N and located throughout the body; calcium channels are the main cause of action potentials in certain smooth muscles, and the N channels regulate neurotransmitter release.
fast channel a protein channel, such as a sodium channel, that becomes activated relatively quickly; a fast voltage-gated channel has a much lower activation potential than does the slow type. See also slow channel.
ligand-gated channel a protein channel that opens in response to the binding of a molecule (the ligand) to the protein, which causes a conformational change in the protein molecule. See also voltage-gated channel.
potassium channel a slow voltage-gated channel selective for the passage of potassium ions, found on the surface of a wide variety of cells, including nerve, muscle, and secretory cells; its functions include regulation of cell membrane excitability, regulation of repetitive low frequency firing in some neurons, and recovery of the nerve fiber membrane at the end of the action potential.
protein channel a watery pathway through the interstices of a protein molecule by which ions and small molecules can cross a membrane into or out of a cell by diffusion; protein channels play a vital role in depolarization and repolarization of nerve and muscle fibers, and may have physical characteristics such as shape or diameter that particularly attract certain ions.
slow channel a protein channel such as the calcium channel that is slow to become activated; a slow voltage-gated channel has a much higher activation potential than does the fast type. See also fast channel.
sodium channel a type of fast channel selective for the passage of sodium ions. Voltage-gated sodium channels are the main causes of depolarization and repolarization of nerve membranes during the action potential. In cardiac cells they produce phase 0 of the action potential.
voltage-gated channel a protein channel that can be opened or closed in response to changes in the electric potential across a cell membrane. See also ligand-gated channel.
water channel a channel in a cell membrane that permits passage of water molecules; chemical substances such as vasopressin cause the opening of new channels and increase permeability.

chan·nel

(chan'ĕl),
A furrow, gutter, or groovelike passageway.
See also: canal.
[L. canalis]

channel

(chăn′əl)
n.
1. A furrow, tube, or other groovelike passageway through which something flows.
2. An aqueous pathway through a protein molecule in a cell membrane that modulates the electrical potential across the membrane by controlling the passage of small inorganic ions into and out of the cell.
Drug slang A regional street term for a vein into which a drug is injected
Paranormal See Channeler, Energy channel
Physiology A multiprotein transmembrane complex—ionophore—with an amphipathic pore, which is hydrophobic on either side of the membrane and hydrophilic inside

channel 

A concept relating to the evidence that information about a particular feature of an image is transmitted and processed in the visual pathway approximately independently of information about other domains. The evidence was obtained from various experiments: matching, threshold elevation, after-effect, etc. Examples: the three channels of colour vision theory; the spatial frequency channels. See waterfall after-effect.

chan·nel

(chan'ĕl)
A furrow, gutter, or groovelike passageway.
[L. canalis]
References in periodicals archive ?
In order to see any differences in the projection pattern of PDF-neurons lacking potassium channels IRK1, we specifically knocked down the inwardly rectifying potassium channels on the PDF expressing neurons using the RNA interference system in flies.
Meniere's disease is associated with single nucleotide polymorphisms in the human potassium channel genes, KCNE1 and KCNE3.
Kv7.2-7.5 voltage-gated potassium channel (KCNQ2-5) opener, retigabine, reduces capsaicin-induced visceral pain in mice.
Tyrosine kinasedependent suppression of a potassium channel by the G protein-coupled m1 muscarinic acetylcholine receptor.
Cortactin controls surface expression of the voltage-gated potassium channel KV10.1.
Autoimmune disorders of neuronal potassium channels. Ann N Y Acad Sci 2003; 998:202-210.
Tsounapi et al., "Blocking of the ATP sensitive potassium channel ameliorates the ischaemia-reperfusion injury in the rat testis," Andrology, vol.
The secretion process is controlled by ATP-dependent potassium channels that are already a target in the development of type 2 antidiabetic drugs.
Alves, "In vivo imaging of tumour xenografts with an antibody targeting the potassium channel Kv10.1," European Biophysics Journal, vol.
Ding, "Inhibitory effects of the ATP-sensitive potassium channel openers cromakalim, pinacidil and minoxidil on the carbachol-response curve in porcine detrusor muscle," Arab Journal of Urology, vol.
For this, we implement similar simulations for sodium ion channels as we did in case of potassium channel block.
Among them, the main physiological functions of sodium channels are propagated action potential (AP).[sup][7] Delayed rectifier potassium channel is one of the major components of AP repolarization course.[sup][8],[9] The ion channel directly affects the generation of AP in neurons, also directly affects the release of neurotransmitter in the heart.

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