Knowledge Tree
sodium channels
Also known as: Na+ channels, sodium channel
Facts (11)
Sources
Neuroanatomy, Neuron Action Potential - StatPearls - NCBI Bookshelf ncbi.nlm.nih.gov 7 facts
claimTetrodotoxin (TTX) is a neurotoxin that inhibits sodium channels, blocking the action potential.
claimNodes of Ranvier are gaps in the myelin sheath that contain high concentrations of sodium channels to restart the action potential along the axon.
claimThe relative refractory period follows the absolute refractory period, during which a neuron may only generate an action potential if a much higher threshold is reached, because some sodium channels are ready to open while many remain inactivated and some potassium channels remain open.
claimThe generation of action potentials is prevented by the removal of extracellular sodium or the inactivation of sodium channels.
claimThe absolute refractory period is the state immediately following the generation of an action potential during which a neuron cannot generate another action potential because sodium channels are inactivated and closed while potassium channels remain open.
claimParamyotonia congenita is a channelopathy resulting from mutations in the gene coding for the alpha-1 subunit of the sodium channel.
claimParalytic shellfish toxins (PSTs) prevent membrane depolarization by blocking sodium entry through inactivated sodium channels, which can lead to severe hypotension, general paralysis, and death from respiratory failure.
Action potential: Definition, Steps, Phases | Kenhub kenhub.com 3 facts
claimDuring early repolarization, the generation of a new action potential is impossible because sodium channels are inactive and require the resting potential to return to a closed state before they can open again.
claimAbsolute refractoriness in a neuron ends when a sufficient number of sodium channels recover from their inactive state.
claimDuring the repolarization phase, sodium permeability decreases due to the closing of sodium channels, and voltage-gated potassium channels open, causing a large potassium efflux that decreases the cell's electropositivity to restore the resting membrane potential.
Thinking about the action potential: the nerve signal as a window to ... frontiersin.org 1 fact
claimThe Hodgkin-Huxley (HH) model predicts the annihilation of colliding action potentials as a consequence of the inactivation of sodium (Na+) channels during the refractory period.