Hyperpolarization following activation of K+ channels by excitatory postsynaptic potentials
| Autor: | Tsuneo Tosaka, Benjamin Libet, Junko Tasaka, Takefumi Miyazaki |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1983 |
| Předmět: |
medicine.medical_specialty
Multidisciplinary Rana catesbeiana Post-tetanic potentiation Chemistry Hyperpolarization (biology) Tetraethylammonium Compounds Inhibitory postsynaptic potential Summation Article Ion Channels Membrane Potentials Kinetics Endocrinology Postsynaptic potential Internal medicine Muscarine Synapses medicine Biophysics Excitatory postsynaptic potential Potassium Graded potential Animals Low-threshold spikes |
| Zdroj: | Nature |
| ISSN: | 1476-4687 0028-0836 |
| Popis: | We have postulated that an excitatory postsynaptic potential (e.p.s.p.) may open voltage-sensitive K+ (‘M’) channels1, in an appropriate depolarizing range, and that this could alter the e.p.s.p. waveform. Consequently, the fast e.p.s.p. in neurones of sympathetic ganglia, elicited by a nicotinic action of acetylcholine (ACh)2, could be followed by a hyperpolarization, produced by the opening of M channels during the depolarizing e.p.s.p. and their subsequent slow closure (time constant∼150 ms)1. This introduces the concept that transmitter-induced p.s.ps may trigger voltage-sensitive conductances other than those initiating action potentials, and that in the present case this could produce a true post-e.p.s.p. hyperpolarization. (Some hyperpolarizations other than inhibitory postsynaptic potentials (i.p.s.ps) have been reported to follow e.p.s.ps3,4.) We show here that this is so. |
| Databáze: | OpenAIRE |
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