The cytosolic Ca2+ concentration in acutely dissociated subfornical organ (SFO) neurons of rats: spontaneous Ca2+ oscillations and Ca2+ oscillations induced by picomolar concentrations of angiotensin II.

The cytosolic Ca2+ concentration in acutely dissociated subfornical organ (SFO) neurons of rats: spontaneous Ca2+ oscillations and Ca2+ oscillations induced by picomolar concentrations of angiotensin II. Brain Res. 2018 Oct 05;: Authors: Izumisawa Y, Tanaka-Yamamoto K, Ciriello J, Kitamura N, Shibuya I Abstract Characteristics of subfornical organ (SFO) neurons were examined by measuring the cytosolic Ca2+ concentration ([Ca2+]i) in acutely dissociated neurons of the rat. SFO neurons, defined by the responsiveness to 50 mM K+ (n=67) responded to glutamate (86%), angiotensin II (AII) (50%), arginine vasopressin (AVP) (66%) and/or carbachol (CCh) (61%), at their maximal concentrations, with marked increases in [Ca2+]i. More than a half (174/307) of SFO neurons examined exhibited spontaneous Ca2+ oscillations, while the remainder showed a relatively stable baseline under unstimulated conditions. Spontaneous Ca2+ oscillations were suppressed when extracellular Ca2+ was removed and were inhibited when extracellular Na+ was replaced with equimolar Nmethyl- D-glucamine. Ca2+ oscillations were unaffected by the inhibitor of Ca2+-dependent ATPases cyclopiazonic acid, the N-type Ca2+ channel blocker ω-conotoxin GVIA and the P/Q-type Ca2+ channel blocker ω-agatoxin IVA, but significantly inhibited by the high-voltage-activated Ca2+ channel blocker Cd2+ and the L-type Ca2+ channel blocker nicardipine. Ca2+ oscillations were also completely arr...
Source: Brain Research - Category: Neurology Authors: Tags: Brain Res Source Type: research