This study investigates dopaminergic neural mechanisms underlying reward-seeking behavior despite adverse consequences using Drosophila melanogaster. Researchers found that optogenetic activation of specific reward-encoding dopaminergic neurons led flies to seek odor cues associated with the activation, even when it meant neglecting food and enduring electric shocks. This behavior was not observed with other dopaminergic neuron populations or with natural sucrose rewards. Antagonism between reward and punishment-encoding neurons explained the persistence of reward seeking despite punishment. Connectome analysis revealed heterogeneous input to reward-encoding neurons, suggesting parallel representation of diverse rewards. The study proposes that similar dopaminergic dysfunction might contribute to maladaptive reward seeking in mammals.

Kristijan D. Jovanoski, Lucille Duquenoy, Jessica Mitchell, Ishaan Kapoor, Christoph D. Treiber, Vincent Croset, Georgia Dempsey, Sai Parepalli, Paola Cognigni, Nils Otto, Johannes Felsenberg, Scott Waddell