Electrophysiological recordings from l-type
labellar chemosensilla were done by the tip-recording method, as
previously described HODGSON 1955Hiroi 2002.
Briefly, the proboscis was fixed at the base of the labellum.
A glass capillary filled with Drosophila Ringer solution
served as an indifferent electrode. 100 mM sucrose solution for
stimulation contained 1 mM KCl as electrolyte. The recorded
signals were digitized and analyzed using the custom software dbWave
Marion-Poll 1996Marion-Poll 1995. Action potentials were detected by a
visually-adjusted threshold set across the digitally filtered signal.
The total number of spikes within 1 second was counted.