Editing Neuron (section)

==All-or-none principle==
[[File:All-or-none law en.svg|thumb|318x318px|As long as the stimulus reaches the threshold, the full response will be given. A larger stimulus does not result in a larger response, and vice versa.<ref name="Kalat, James W-2016">{{Cite book |last=Kalat, James W |title=Biological psychology |publisher=Cengage Learning |year=2016 |isbn=9781305105409 |edition=12 |location=Australia |oclc=898154491}}</ref>{{Rp|31}}]]
{{Main|All-or-none law}}
The conduction of nerve impulses is an example of an [[All-or-none law|all-or-none]] response. In other words, if a neuron responds at all, then it must respond completely. Greater intensity of stimulation, like brighter image/louder sound, does not produce a stronger signal but can increase firing frequency.<ref name="Kalat, James W-2016" />{{Rp|31}} Receptors respond in different ways to stimuli. Slowly adapting or [[tonic (physiology)|tonic receptors]] respond to a steady stimulus and produce a steady rate of firing. Tonic receptors most often respond to increased stimulus intensity by increasing their firing frequency, usually as a power function of stimulus plotted against impulses per second. This can be likened to an intrinsic property of light where greater intensity of a specific frequency (color) requires more photons, as the photons can not become "stronger" for a specific frequency.

Other receptor types include quickly adapting or phasic receptors, where firing decreases or stops with a steady stimulus; examples include [[Human skin|skin]] which, when touched causes neurons to fire, but if the object maintains even pressure, the neurons stop firing. The neurons of the skin and muscles that are responsive to pressure and vibration have filtering accessory structures that aid their function.

The [[pacinian corpuscle]] is one such structure. It has concentric layers like an onion, which form around the axon terminal. When pressure is applied and the corpuscle is deformed, mechanical stimulus is transferred to the axon, which fires. If the pressure is steady, the stimulus ends; thus, these neurons typically respond with a transient depolarization during the initial deformation and again when the pressure is removed, which causes the corpuscle to change shape again. Other types of adaptation are important in extending the function of several other neurons.<ref>{{cite book | last1 = Eckert | first1 = Roger | last2 = Randall | first2 = David | name-list-style = vanc | title = Animal physiology: mechanisms and adaptations | year = 1983 | publisher = W.H. Freeman | location = San Francisco | isbn = 978-0-7167-1423-1 | page = [https://archive.org/details/animalphysiology0000ecke/page/239 239] | url = https://archive.org/details/animalphysiology0000ecke/page/239 }}</ref>