α. 1800s– electrotonus.
β. 1800s electrotone.
electrotonusn.
/ᵻˌlɛktrəʊˈtəʊnəs/, U.S. /əˌlɛktroʊˈtoʊnəs/, /iˌlɛktroʊˈtoʊnəs/ Physiology.
Originally: a state of altered excitability produced in a nerve by passing an electric current through it (cf. anelectrotonus n., catelectrotonus n.). Later also: the passive spread of depolarization along a neurite, neuron, or other excitable cell.
ΚΠ
1860 A. C. Garratt Electro-physiol. & Electro-therapeutics ii. 90 The electro-tonic state, or ‘electrotonus,’ so nicely examined by him [sc. M. Dubois-Reymond], arrests our first attention.
1861 Year-bk. Med., Surg., & Allied Sci. (New Sydenham Soc.) 52 (title) Contributions to the Physiology of Electrotone.
1877 M. Foster Text Bk. Physiol. i. ii. 53 The polarizing (constant current) is said therefore to throw the nerve into a state of electrotonus.
1939 Proc. Royal Soc. 1938–9 B. 126 92 The spread of the polarization potential (electrotonus) is much less extensive in crab fibres than it is in medullated nerve.
1973 Jrnl. Cell Biol. 58 221/1 The decrease in electrotonus at each point was also similar for normal and cancerous cells.
2006 Clin. Neurophysiol. 117 1458/2 Threshold electrotonus is the only clinically available method that enables insight into nodal and internodal axonal membrane conductances in humans in vivo.
This entry has been updated (OED Third Edition, June 2008; most recently modified version published online March 2022).
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n.1860