Optogenetic dissection of dopamine subpopulations in Drosophila reveals interplay between reward and aversion

Dopamine is an essential component in the neural pathway for attractive and aversive behavior. Dopaminergic (DA) neurons are known to have a key role in neurotransmission which can result in the modulation of different behaviors as well as the manifestation of different mental health disorders. Drosophila share similar genetics that are associated with several neurodegenerative diseases and disorders in humans. Furthermore, previous studies have shown conservation of DA neurons between humans and Drosophila which facilitate research using Drosophila as a model organism. In this study, we initially developed and tested a novel optogenetics system, which targeted neurons with spatial specificity, that activated or inhibited neurons through channelrhodopsin microbial opsins that are sensitive to red light. This system was then used to investigate the DA subsets that mediate attractive and aversive behavior. The activation of PPL1 clusters mostly resulted in aversive behavior as aligned with the literature, however activation of clusters with output neurons (PPL1 & PAM) concluded with different results.