Fig. 5: Mapping the neural circuit of social approach behaviour.
From: Social attraction in Drosophila is regulated by the mushroom body and serotonergic system
Schematic (a) and results (b) of investigating the visual pathway in social interaction, via inactivating visual neurons in the flies without olfactory organs. Schematic (c) and results (d) of investigating the olfactory pathway in social interaction, by testing flies in the dark with blocked KCα/β neurons. e Two classes of α/β neurons exhibit different cross-section appearances at the peduncle. (e-a) Schematic of a cross-section of the peduncle of MB. Cross-sections of the expression patterns of 17d (e-b), NP6649 (E-c), NP3061 (e-d), and NP5286 (e-e) at peduncle, visualized by GFP. f NP3061 (f-a) and R84C10 (f-b) show specific expressions in the mushroom body and fan-shaped body, respectively. g Simultaneous inactivation of α/β surface neurons (NP3061) and F5 neurons (R84C10) reduced social approach behaviour, while inactivation of either population alone did not affect social interaction. h Visualization of the synaptic connections between F5 neurons, α/βs neurons, and γ neurons in the calyx by t-GRASP. (h-a) Schematic of the locations of the presynaptic structure labelled by R84C10 (green) and postsynaptic structure labelled by R72B08 (magenta). (h-b) t-GRASP signals indicated contacts between KCγ neurons (R72B08-Gal4) and F5 neurons (R84C10-LexA) in the calyx region (coloured box). (h-c and d) Magnified views in the boxed regions of (h-b). (h-e) Schematic of the locations of the presynaptic structure labelled by R44E04 (Green) and postsynaptic structure labelled by R72B08 (magenta). (h-f) t-GRASP signals showed the contacting sites between KCα/βs neurons (R44E04-LexA) and KCγ neurons (R72B08-Gal4) in the calyx region (coloured box). (h-g and h) Magnified views in the boxed regions of (h-f). The neuropil was counterstained with the antibody against nc82 (magenta). Scale bars = 50 μm, except in (e: 10 μm) and (h-c, d, g, and h: 25 μm). i A diagram to show the neural circuit mediating social attraction. Results are presented as a box and whisker plot; the whiskers indicate the minimum and maximum, the box includes the 25th–75th percentile, and the line in the box indicates the median of the data set. Statistical analysis: unpaired t-test. ns: P > 0.05, **P < 0.01, ***P < 0.001.
