The influence of extracellular calcium on the response of fly photoreceptors

Abstract

This paper presents a systematic investigation of the influence of the extracellular concentration of calcium ([Ca2+]0) on the electrophysiological response of the fly's photoreceptors (R1–R6) to light. The hemisected heads of flies were perfused with a standard medium containing 10−4 mol/1 CaCl2 and in this medium the intracellularly recorded response of the cell was virtually identical to the normal response obtained in vivo. All the effects of changing the [Ca2+]0 could be reversed within 5 min by perfusing the eye with the standard medium.