Title: | Voltage- and calcium-activated currents in cultured olfactory receptor neurons of male Mamestra brassicae (Lepidoptera) |
Address: | "INRA, Unite de Phytopharmacie et des Mediateurs Chimiques, Route de Saint Cyr, 78026 Versailles Cedex, France. plucas@versailles.inra.fr" |
ISSN/ISBN: | 0379-864X (Print) 0379-864X (Linking) |
Abstract: | "Insect olfactory receptor neurons (ORNs) grown in primary cultures were studied using the patch-clamp technique in both conventional and amphotericin B perforated whole-cell configurations under voltage-clamp conditions. After 10-24 days in vitro, ORNs had a mean resting potential of -62 mV and an average input resistance of 3.2 GOmega. Five different voltage-dependent ionic currents were isolated: one Na(+), one Ca(2+) and three K(+) currents. The Na(+) current (35-300 pA) activated between -50 and -30 mV and was sensitive to 1 microM tetrodotoxin (TTX). The sustained Ca(2+) current activated between -30 and -20 mV, reached a maximum amplitude at 0 mV (-4.5 +/- 6.0 pA) that increased when Ba(2+) was added to the bath and was blocked by 1 mM Co(2+). Total outward currents were composed of three K(+) currents: a Ca(2+)-activated K(+) current activated between -40 and -30 mV and reached a maximum amplitude at +40 mV (605 +/- 351 pA); a delayed-rectifier K(+) current activated between -30 and -10 mV, had a mean amplitude of 111 +/- 67 pA at +60 mV and was inhibited by 20 mM tetraethylammonium (TEA); and, finally, more than half of ORNs exhibited an A-like current strongly dependent on the holding potential and inhibited by 5 mM 4-aminopyridine (4-AP). Pheromone stimulation evoked inward current as measured by single channel recordings" |
Keywords: | "Action Potentials/physiology Amphotericin B/pharmacology Animals Barium/pharmacokinetics Calcium/*physiology Calcium Channels/*physiology Cells, Cultured Electric Conductivity Ion Channels/physiology Lepidoptera/cytology/*physiology Male Olfactory Recepto;" |
Notes: | "MedlineLucas, Philippe Shimahara, Takeshi eng England 2002/08/30 Chem Senses. 2002 Sep; 27(7):599-610. doi: 10.1093/chemse/27.7.599" |