Biologists Use Fruit Flies to Shed Light On How Color Vision Is Processed

By James Devitt

Biologists in NYU’s Center for Developmental Genetics have published a pair of studies that shed light on how color vision is processed in the brain.

      One study, which appeared in the journal PloS Biology, identified a new class of photoreceptors in the retina of fruit flies, which adds to our understanding of how the pigments of the eye that confer color vision are regulated. The findings may also have implications for the regulation of olfactory receptors, which are responsible for the detection of smells. In the second, the NYU researchers mapped the medulla circuitry in fruit flies, setting the stage for research on how color vision is processed. The work, which appeared in the journal Current Biology, will allow future scholarship to explore how color vision is processed in the optic lobe of the fruit fly Drosophila, providing a paradigm for more complex systems in vertebrates.

      “Future experiments using our results will help us to reveal the exact function of the optic lobe cells in these complex circuits and to reach a better understanding of the mechanisms that govern the physiology of vision both in vertebrates and invertebrates,” said professor Claude Desplan, head of the center and co-author on both studies.

      Fruit flies can be analyzed and manipulated in exquisite detail by biologists and serve as a powerful model system to understand biological processes such as vision.

      In the PloS Biology study, the NYU researchers examined Drosophila’s eight photoreceptors. Six of these mediate broad-spectrum detection of motion and are similar to human rods, while two photoreceptors mediate color vision and are similar to the human cone photoreceptors. Their results revealed a new class of photoreceptors that violates the one rhodopsin–one photoreceptor rule.

      In the Current Biology study, Desplan and postdoctoral fellow Javier Morante, the study’s co-author, reconstructed the neural network in Drosophila’s medulla—the brain structure where color photoreceptors project—focusing on neurons likely to be involved in processing color vision. They identified the full complement of neurons in the medulla and developed analytical tools that will allow scientists to functionally manipulate the network and test both activity and behavior.

      Both studies were supported by grants from the National Institutes of Health.