Calcium imaging reveals nicotinic acetylcholine receptors on cultured mushroom body neurons

Abstract

1. We used fluorescence imaging with the visible wavelength indicator fluo-3 to investigate the calcium responses to cholinergic ligands of honeybee Kenyon cells in primary culture.<br />2. Application of acetylcholine ( ACh) or nicotine, but not pilocarpine, promoted a calcium influx into the cell body and neurites. The increase in intracellular calcium after ACh stimulation was blocked by tu-bungarotoxin. These results support previous histochemical studies that suggested the expression of nicotinic cholinergic receptors on Kenyon cells.<br />3. After depolarization with high K+ solution fluorescence increased<br />in the somata and neurites, which indicates the presence of<br />voltage-gated Ca *+ channels in Kenyon cell membranes.