Topic: glutamatergic inhibition

Nonlinear, multiplication-like operations carried out by individual nerve cells greatly enhance the computational power of a neural system, but our understanding of their biophysical nature is scant. We pursue this problem in the Drosophila ON motion vision circuit, where we record the membrane potentials of direction-selective T4 neurons and of all their columnar input elements in response to visual and pharmacological stimuli in vivo. Our electrophysiological measurements and conductance-based simulations suggest a passive supralinear interaction between two distinct types of synapse on T4 d

Visual motion provides us with rich cues about the three-dimensional structure of our environment. However, it is generally unknown how circuits of neurons decode spatial information carried by patterns of visual motion. Here, we study the neural mechanisms of a collision avoidance behavior in walking Drosophila fruit flies as a simple model of motion-based spatial vision. In psychophysical experiments, we observed that flies exhibit slowing upon encountering small objects moving back-to-front in the frontolateral visual field. With a simple simulation, we demonstrate that this slowing can be