Figure 4.

Ruling out the contribution of brain MZ317 neurons to olfactory perception changes

(A) Cellular characterization of the Mz317-Gal4 driver in the adult brain. Mz317-Gal4 driver expression in the brain corresponds to nonneuronal (glial) cells, as seen in the Mz317-Gal4/elav-Gal80; UAS-mcD8:GFP flies, but it also affects a limited number of nonglial (neuron) cells, as seen in the Mz317-Gal4/repo-Gal80; UAS-mcD8:GFP flies. Three neurons and their axons affect a small region close to the antennal glomeruli. Scale bar, 100 μm.

(B) The main glomeruli that responded to the 3 odorants used in optogenetic experiments are shown in color according to DOOR 2.0.⁴³ Scheme modified from.⁴⁴

(C) Detail of GFP marker expression close to the antennal lobe.

(D and E) Optogenetic activation of MZ317 glial cells, excluding neurons (in recombinant lines MZ317-Gal4, elav-Gal80; 42 in green and 24 in magenta), by channel rhodopsin recapitulates the response observed with the original Mz317-Gal4 driver to ethyl acetate (10^−1.5), diminishing olfactory sensitivity (∗∗∗ = p < 0.001; ∗∗ = p < 0.01). All values represent the mean ± SEM of N = 20 for the experiment in (D), and in (E), N correspond to 10, 9, 6, 7, 8, and 7 replicate tests, respectively, for each group from left to right.