Figure 11.

Projection neurons similarly responsive to the two enantiomers of linalool. A, B, Two examples of non-enantioselective PNs (a total of 12 were morphologically characterized in 12 different animals). Non-enantioselective PNs had arborizations restricted to glomerulus in the vicinity of the latLFG and glomerulus 15, and extended an axon (Ax) into the protocerebrum. Dotted lines represent the outlines of the glomeruli housing the arborizations of these PNs. Images are confocal stacks collected from whole-mount preparations. Scale bars, 100 μm. D, Dorsal; L, lateral. C, Responses of a morphologically characterized, non-enantioselective PN. This neuron was stimulated with the odor compounds shown in this figure, and also with nerol, ocimene, myrcene, benzyl alcohol, and hexanol. All volatiles were presented at a concentration of 1:100. The arrows indicate the arrival of the stimulus at the antenna (calculated from the EAG responses). This neuron responded to stimulation with all odor compounds except the nonterpenoids hexanol and benzyl alcohol. Calibration: 2.5 mV, 400 msec. D, E, Net number of spikes (mean ± SEM) evoked by stimulation with (–) and (+)linalool at a concentration of 1:1000 (D) or 1:100 (E). Data were obtained from 12 different PNs (n = 5 in A; n = 7 in B). Means coded by different lowercase letters differ significantly. Responses to (–) and (+)linalool were statistically different from the blank [repeated-measures ANOVAs: in D, df = 2,8; F = 28.17; p < 0.0005; post hoc Tukey tests significant at the 0.01 level. In E, df = 2,12; F = 46.25; p < 0.000005; post hoc Tukey tests significant at the 0.0005 level]. Responses to (–) and (+)linalool were not statistically different from each other (Tukey tests: p > 0.05).