The Drosophila Brain on Cocaine at Single Cell Resolution
To identify specific cell populations that respond to acute cocaine exposure, we analyzed single cell transcriptional responses in duplicate samples of flies that consumed fixed amounts of sucrose or sucrose supplemented with cocaine, in both sexes. Unsupervised clustering of the transcriptional profiles of a total of 86,224 cells yielded 36 distinct clusters. Annotation of clusters based on gene markers revealed that all major cell types (neuronal and glial) as well as neurotransmitter types from most brain regions were represented. The brain transcriptional responses to cocaine showed profound sexual dimorphism and were considerably more pronounced in males than females. Differential expression analysis within individual clusters indicated cluster-specific responses to cocaine. Clusters corresponding to glia and Kenyon cells of the mushroom bodies showed especially large transcriptional responses following cocaine exposure. Cluster specific co-expression networks and global interaction networks revealed a diverse array of cellular processes affected by acute cocaine exposure. These results provide an atlas of sexually dimorphic cocaine-modulated gene expression in a model brain. Overall design: Profiling of 8 samples consisting of 20 Drosophila brains each, 2 conditions (sucrose and cocaine), 2 sexes (male and female) and 2 replicates