Figure 2

Anatomy, neurotransmitter patterns, and sound responses of JO neurons in D. melanogaster and D. simulans. (a) JO-neuron cell number. Gray dots and colored crossbar indicate the values of each sample and median, respectively. ***p < 0.001; ART ANOVA. (b) ChAT signals in JO. Frontal confocal sections of JO within the second antennal segment are shown. Cell bodies of JO neurons were labeled with anti-Elav antibodies (magenta). JO neurons in both species were labeled with anti-ChAT antibodies (green). D Dorsal, L Lateral. (c) JO neuron axons innervating the AMMC region of the brain. JO neuron axons that express GFP by nanchung-GAL4 driver of D. melanogaster are shown in green. Magenta signals show neuropil visualized using the nc82 antibody. A white dashed square area is shown in (d). (d) Frontal confocal sections of the AMMC along the trajectory of JO neuron axons in D. melanogaster (top) and D. simulans (bottom) females. The fluorescent signals surrounded by dotted lines, which indicate the neurites projecting to the AMMC, are determined to be the axons of JO neurons (see “Methods”). D Dorsal, L Lateral. JON JO neurons, MT main trunk, LC lateral core region, A zone A, B zone B, C zone C, D zone D, E zone E. The depth (µm) from the most frontal section was annotated at the bottom left of each panel. (e) Experimental setup of calcium imaging. (f) Calcium responses of JO neuron axons to pure tones in D. simulans (Left, Middle). The sound stimulus, 167-Hz or 333-Hz pure tone, lasted 3 s (shaded gray area). Thin and bold lines show time traces of the response in each individual and the average of all individuals, respectively. The ROI (outlined in yellow) was set at the axon bundle of JO neurons where the fluorescent signals are observable during the sound stimulus (Right). P Posterior, L Lateral.