Fig. 5: GABAergic synapses, but not dopaminergic synapses, onto dFSB neurons display temperature-sensitive activity.

a Dendrites and axonal projections from dFSB neurons were visualized by transgenic expression of the fluorescent marker proteins DenMark (magenta) and syt.eGFP (cyan), respectively (23E10-Gal4/UAS-DenMark, UAS-syt.eGFP). Weak DenMark signals in the dFSB region may indicate leaky expression in non-dendritic regions⁸⁰. Alternatively, a minor population of dFSB neurons may have dendrites in the dFSB region. b Transgenic flies were pre-entrained in LD cycles at 21 °C (blue) or 29 °C (orange), and their whole brains were dissected out. The fluorescence images of whole-mount brains were obtained using a multi-photon microscopy. Representative z-stack images of the synaptic GRASP (syb:GRASP) signals from GABAergic (lexAop-nSyb-spGFP1-10, UAS-CD4-spGFP11/+; GAD1-LexA/23E10-Gal4) or dopaminergic neurons (lexAop-nSyb-spGFP1-10, UAS-CD4-spGFP11/+; TH-LexA/23E10-Gal4) to dFSB neurons were shown. c The fluorescence intensity of the syb:GRASP at the dendritic regions of dFSB neurons was quantified using ImageJ software. Fluorescence signals above a threshold level (i.e., background) were integrated from each hemisphere, and averaged per genotype at each temperature (n = 18–22 hemispheres). Data represent average ± SEM. n.s., not significant; ***P < 0.001 as determined by Mann–Whitney U test.