Detection of discrete objects underlies seemingly disparate behaviors such as courtship, aggression, and avoidance in Drosophila melanogaster. Vision starts as a rather abstract initial percept at the retina, from which visual features, such as color, motion, or discrete objects, are extracted and relayed to the central brain. Similar to the mammalian retinal ganglion cells in the optic nerve, the insect visual projection neurons relay combinations of visual features to the central brain. Our work uncovered LC10a visual projection neurons as essential for the male to remain close to the female during courtship. Recently, we identified LC10d visual projection neurons as important players in avoidance of a discrete object that is unidentified at the chemosensory level. LC10a and LC10d neurons project to the largest retinorecipient area of the fly brain, the central unit of the anterior optic tubercle (AOTu). The AOTu central unit retains spatial organization and receives information from several different neuron types. LC10a and LC10d establish two parallel pathways that are associated with two distinct behaviors, attraction and avoidance. Both LC10a and LC10d neuron types have about 100 cells on either hemisphere. The AOTu central unit output neuron types identified so far are composed of 2 to 6 cells per hemisphere, suggesting there is a massive synthesis of information from LC10a or LC10d to downstream neurons. Current work in the lab aims to characterize the transformations occurring from stimulus-correlated visual information entering the AOTu to the output signal correlated with motor actions, such as turning towards or away from another fly.
Institute of Medical Psychology