Figure S4.
An active mechanism increases bilateral contrast in cVA sensing, related to Figure 4
(A) Image sequence from a video of a bilateral male presentation. A fixed female fly is placed in a holder for two-photon imaging (top). A male fly is glued to a needle that is moved by an externally controlled micromanipulator. Note that at timepoints 0 and 11 s and at timepoints 12 and 31 s, the stimulus fly has been positioned at the same two locations with micron precision. Scale bar, 1 mm.
(B) lPN responses to a male presented ipsilaterally (left) and contralaterally (right) with respect to the imaging ROI. Repeated from Figure 4F. Average response from 14 flies (28 hemispheres), 6 trials, gray area is SEM. Right: mean responses of hemispheres to ipsi- and contralateral stimuli.
(C) Same as (B), but the receiver fly’s antennae were left to move freely. n = 7, 14 hemispheres, 6 trials.
(D) Same as (B), recording responses in male flies. n = 6, 12 hemispheres, 6 trials.
(E) Bilateral contrast in lPNs is unaffected by fixing the antennae in place or the sex of the fly that responds to the male stimulus. Calculated as in Figure 4E.
(F) lvPNs respond stronger to a male presented ipsilaterally, stimulus as in (B), intact antennae. n = 11, 22 hemispheres, 6 trials.
(G) lPN GCaMP6f responses to a male presented in the middle after blocking the contralateral antenna (same stimulus as in Figure 2G), n = 6, 6 trials.
(H) Same as (C), but the ipsilateral antenna is blocked, n = 6, 6 trials.
(I) Comparison of lPN and lvPN bilateral contrast.
(J) Schematic of the expected circuit consequences of antennal block manipulations. Same circuit as in Figure 4O. Left: intact antennae, all circuit elements are functional. Middle: contralateral antenna blocked, contralateral ORNs are not functional, as a result il3LN6 are silent. Ipsilateral antenna blocked: ipsilateral ORNs are not functional, stimulating the contralateral antenna results in parallel excitation and inhibition of lPNs; the net effect of this depends on the position of the stimulus as shown in Figure 4D, see also (D).
(K) Effect of contralateral antenna block on lPN responses to ipsilateral (top) and contralateral (bottom) male presentation. Responses in the same ROIs were compared with paired t tests before and after blocking the contralateral antenna. Data from Figures 4G and 4H; n = 8, 6 trials.
(L) GABA and il3LN6 soma co-immunostaining. Top left: a-GABA staining; top right: VT046100-GAL4 × CD8::GFP, anti-GFP staining; bottom left: anti-nc82 staining; bottom right: composite image. Scale bars, 20 μm.