Open AccessDepolarization-induced Ca2+ increase in isolated neurosecretory nerve terminals measured with fura-2.
Author(s) -
Daniel Brèthes,
Govindan Dayanithi,
Lucienne Letellìer,
J Nordmann
Publication year - 1987
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.84.5.1439
Subject(s) - veratridine , depolarization , free nerve ending , stimulation , intracellular , biophysics , fura 2 , chemistry , medicine , endocrinology , biology , anatomy , sodium , biochemistry , sodium channel , cytosol , organic chemistry , enzyme
The free Ca2+ concentration in isolated rat neurohypophysial nerve endings was measured using the Ca2+ indicator fura-2. Depolarization with high K, veratridine, or electrical stimulation induced an increase in intracellular Ca2+ concentration that was abolished by agents known to block voltage-sensitive Ca channels. Electrical stimulation of the isolated nerve endings with a pulse pattern similar to that recorded in vivo from the hypothalamic magnocellular neurons showed that the increase in intracellular Ca2+ concentration was not only a function of the applied frequency but also of the duration of the silent interburst intervals. The relationship between the cytoplasmic free Ca concentration and the release of neuropeptides is discussed.