SODIUM CALCIUM EXCHANGER IN RAT OLFACTORY NEURONS/

The chemo-electrical transduction process in olfactory neurons is acco mpanied by a rapid and transient increase in intracellular calcium con centrations. The notion that Na+/Ca2+ exchanger activities may play a major role in extruding calcium ions out of the cell and maintaining C a2+ homeostasis in olfactory receptor cells was assessed by means of l aser scanning confocal microscopy in combination with the fluorescent indicators Fluo-3 and Fura-Red. The data indicate that high exchanger acitivity, which was inhibited by amiloride derivatives, is located in the dendritic knob and probably in the olfactory cilia. This result w as supported by experiments using specific antiserum raised against re tinal Na+/Ca2+ exchanger protein which labelled an immunoreactive prot ein of 230 kDa in Western blots from olfactory tissue and strongly sta ined the ciliary layer of the olfactory epithelium. (C) 1997 Elsevier Science Ltd.