Definition
Stretch-activated ion channels are mechanotransducers which conduct ionic currents by responding to stress in the cell membrane. To be identified as stretch-activated, the ion channel must open and close in response to membrane tension.Mechanotransduction, an electrical signal resulting from a mechanical stimulus, occurs via the opening of stretch-activated ion channels due to membrane deformation. The opening of these channels results in a non-specific ionic flow, which depolarizes the afferent nerve fiber, and may produce action potentials with sufficient depolarization. The opening of these channels is central to a neuron’s response to pressure, often osmotic pressure and blood pressure, to regulate ionic flow in internal environments. There are two mechanisms for which these channels open. The prokaryotic model suggests that stretch-activated channels open directly in response to force to the membrane, whereas the mammalian hair cell model involves a tether bound both to the channel and to the extracellular matrix or cytoskeleton. Force on the membrane then displaces the tether, creating tension which opens the channel.
Read more about this topic: Stretch-activated Ion Channel
Famous quotes containing the word definition:
“It’s a rare parent who can see his or her child clearly and objectively. At a school board meeting I attended . . . the only definition of a gifted child on which everyone in the audience could agree was “mine.””
—Jane Adams (20th century)
“Mothers often are too easily intimidated by their children’s negative reactions...When the child cries or is unhappy, the mother reads this as meaning that she is a failure. This is why it is so important for a mother to know...that the process of growing up involves by definition things that her child is not going to like. Her job is not to create a bed of roses, but to help him learn how to pick his way through the thorns.”
—Elaine Heffner (20th century)
“The physicians say, they are not materialists; but they are:MSpirit is matter reduced to an extreme thinness: O so thin!—But the definition of spiritual should be, that which is its own evidence. What notions do they attach to love! what to religion! One would not willingly pronounce these words in their hearing, and give them the occasion to profane them.”
—Ralph Waldo Emerson (1803–1882)