| 释义 |
ˌhyperpolariˈzation Physiol.
[f. hyper- + polarization.]
An increase in the potential difference across the membrane of a nerve fibre above the normal resting potential, so that the inside of the fibre becomes (or is) even more negative with respect to the outside.
1946Lorente de Nó & Feng in Jrnl. Cellular & Compar. Physiol. XXVIII. 412 This overshooting is analogous to the temporary hyperpolarization of the membrane (positive after-potential) which occurs after the end of tetani. 1955Acta Physiol. Scand. XXXV. 12 The hyperpolarization usually amounts to 25–35 mV. Ibid., The rate of hyperpolarization is about 150 mV/sec. 1966C. F. Stevens Neurophysiol. ii. 13 Any change which decreases the inside-outside potential difference is known as a depolarization, whereas an increase in the membrane potential is called a hyperpolarization. 1971Nature 9 July 123/1 Lundberg inserted intracellular electrodes in secretory cells of this gland and observed a hyperpolarization of 5–20 mV with a latency of 200–400 ms after applying single shocks to the chorda tympani nerve.
So hyperˈpolarize v. trans., to produce such a change in (a nerve fibre); intr., to undergo such a change; hyperˈpolarizing vbl. n.
1950Jrnl. Cellular & Compar. Physiol. XXXV. Suppl. ii. 105 It appears that presynaptic impulses may exert upon the ganglion cells a catelectrotonic (depolarizing) action as well as an anelectrotonic (hyperpolarizing) action. 1955Jrnl. Physiol. CXXX. 394 On hyperpolarizing the motoneurone..the amplitude of the e.p.s.p. was only slightly affected. 1971Nature 23 July 269/2 In one pair of touch cells..a depolarizing or a hyperpolarizing synaptic potential was observed when the anterior or the posterior cell was stimulated. 1973Ibid. 9 Mar. 102/1 Most of these cells only hyperpolarize in response to light. |