Fig. 7: Subsets of DN1ps were TkR86C-positive and were required for M activity extension in HSD.
From: Metabolic control of daily locomotor activity mediated by tachykinin in Drosophila
a, b Locomotor activities of given genotypes of flies (denoted on top) were analyzed in NSD and HSD on a 16L:8D cycle at 29 °C. Daily activity profiles of flies on day 7 are shown. b M activity offset of individual flies on day 7 is shown. Bars indicate mean ± SEM values (n = 22–30). Statistically significant differences in M activity offset between control (R18H11 > d2, w1118) and TkR86C knockdown flies (R18H11 > d2, TkR86C Ri) (independent t test): *P < 0.05, ***P < 0.001. c, e Flies of the indicated genotypes (denoted on top) were maintained on a 16L:8D cycle at 29 °C. Brains were dissected at ZT2 and stained with anti-GFP (cyan blue) and anti-CLK (red) antibodies. The middle and right panels show a magnified image of the boxed region in the left panel. Arrow indicates a TkR86C-positive DN1p. All scale bars represented 20 μm. d Brains were stained with anti-GFP (cyan blue) and anti-RFP (red) antibodies. Dashed circle marks R18H11 and TkR86C positive cells in DN1p region. All scale bars represented 20 μm. f Differences in M activity offset on day 7 between NSD and HSD groups (ΔM activity offset) for given genotypes of flies are shown (n = 26–31). Statistically significant differences in ΔM activity offset between control (TkR86C202036 > w1118 or TkR86C204235 > w1118) and TkR86C knockdown flies (TkR86C202036 > TkR86C Ri or TkR86C204235 > TkR86C Ri) (independent t test): ***P < 0.001. g Schematic of our model for a HSD-induced M activity extension in flies. DTk signaling is transmitted via TkR86C receptors onto postsynaptic DN1ps. The activation of DTk neurons reduced intracellular Ca2+ levels in DN1ps indicating the inhibitory connection between two neurons. A HSD increased the connections between DTk and DN1ps anatomically and physiologically. DN1ps promote activity at dawn and sleep at midday, we hypothesized that DTk modulates DN1ps activity in a time-gated manner to inhibit siesta, leading to the M activity extension (marked as a dashed line, because it was not proven in our study).
