Threshold potential

<p>In <a href="/facts/Electrophysiology/VPd5VYzm">electrophysiology</a>, the threshold potential is the critical level to which a <a href="/facts/Membrane_potential/DpNG14c7">membrane potential</a> must be <a href="/facts/Depolarization/qGX8lFXE">depolarized</a> to initiate an <a href="/facts/Action_potential/Sz8yCRqx">action potential</a>. In <a href="/facts/Neuroscience/o5RV8Cas">neuroscience</a>, threshold potentials are necessary to regulate and propagate signaling in both the <a href="/facts/Central_nervous_system/k8I6To97">central nervous system</a> (CNS) and the <a href="/facts/Peripheral_nervous_system/KjVpVnHU">peripheral nervous system</a> (PNS).
</p><p>Most often, the threshold potential is a membrane potential value between –50 and –55 <a href="/facts/Volt/KF18MXP2">mV</a>, but can vary based upon several factors. A <a href="/facts/Neuron/G7CyTVdH">neuron</a>'s resting membrane potential (–70 mV) can be altered to either increase or decrease likelihood of reaching threshold via <a href="/facts/Sodium/eYuSPu2V">sodium</a> and <a href="/facts/Potassium/FWPwS7Rj">potassium</a> ions. An influx of sodium into the cell through open, <a href="/facts/Voltage-gated_sodium_channel/pXb4n2Vz">voltage-gated sodium channels</a> can depolarize the membrane past threshold and thus excite it while an efflux of potassium or influx of <a href="/facts/Chloride/m9NUaUDR">chloride</a> can <a href="/facts/Hyperpolarization_(biology)/XNH4zPwN">hyperpolarize</a> the cell and thus inhibit threshold from being reached.
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Threshold potential open-in-new

Threshold potential