How neural feedback enables flexible visual processing in Drosophila

The visual system can function across variable scene statistics and behavioral contexts. This flexibility arises in part from neural feedback, which shapes visual processing to align with prevailing stimulus conditions and behavioral goals. In the fruit fly Drosophila melanogaster, extensive genetic and connectome resources allow feedback connections of identified cells to be linked to their functions in the visual system. Here, we review key mechanisms and functions of feedback in the Drosophila visual system, drawing parallels to vertebrate models, where feedback also plays an important role in visual processing. We conclude by arguing that connectomes are critical in this task and that cracking feedback circuits in flies can help guide our understanding of feedback in larger brains.