At the reversal potential, there is no net flow of ions from one side of the membrane to the other.
[4][5] The membrane voltage opposes the flow of the potassium ions out of the cell and the ions can leave the interior of the cell only if they have sufficient thermal energy to overcome the energy barrier produced by the negative membrane voltage.
[5] An important concept related to the equilibrium potential is the driving force.
[5] Relatedly, the membrane current per unit area due to the type
For instance several excitatory ionotropic ligand-gated neurotransmitter receptors including glutamate receptors (AMPA, NMDA, and kainate), nicotinic acetylcholine (nACh), and serotonin (5-HT3) receptors are nonselective cation channels that pass Na+ and K+ in nearly equal proportions, giving the reversal potential close to zero.
The inhibitory ionotropic ligand-gated neurotransmitter receptors that carry Cl−, such as GABAA and glycine receptors, have reversal potentials close to the resting potential (approximately –70 mV) in neurons.
[2] This line of reasoning led to the development of experiments (by Akira Takeuchi and Noriko Takeuchi in 1960) that demonstrated that acetylcholine-activated ion channels are approximately equally permeable to Na+ and K+ ions.
[2] A general expression for reversal potential of synaptic events, including for decreases in conductance, has been derived.