Reconstruction of neural circuits controlling insect eye movements

The eyes of many animals move, constantly changing the spatial relationships of gaze and objects. Many visual tasks thus require an accurate estimate of the current eye position. It is thought that both corollary discharge signals and proprioceptive feedback play a role in conveying eye position signal. However, the mechanisms of proprioception for eye movements is still not fully understood, even in vertebrates. It has been shown recently that the fruit fly, Drosophila melanogaster, moves its retinas beneath the stationary lenses of its compound eye using two muscles [1]. Some of these movements strongly resemble vertebrate eye movements. This provides an excellent opportunity to gain a detailed understanding of proprioceptive feedback from eye movements in a small and genetically accessible organism. Here, we aim to anatomically describe mechanosensory neurons innervating the fly eye muscles and trace their axonal projections to the brain.