PhotoTransduction in the Retina of the Fruit Fly

The retina and the lamina neuropil of the early visual system of the fruit fly brain are, respectively, described by the publications below. Open source code and documentation is available at FlyBrainLab.

  1. Aurel A. Lazar, Nikul H. Ukani and Yiyin Zhou, The Cartridge: A Canonical Neural Circuit Abstraction of the Lamina Neuropil - Construction and Composition Rules, Neurokernel Request for Comments, Neurokernel RFC #2, January 2014.
  2. Aurel A. Lazar, Konstantinos Psychas, Nikul H. Ukani and Yiyin Zhou, A Parallel Processing Model of the Drosophila Retina, Neurokernel Request for Comments, Neurokernel RFC #3, August 2015.
  3. Aurel A. Lazar, Nikul H. Ukani, and Yiyin Zhou, Sparse Identification of Contrast Gain Control in the Fruit Fly Photoreceptor and Amacrine Cell Layer, The Journal of Mathematical Neuroscience, Volume 10, Number 3, Springer Open, February 2020.

The above video shows a visual evaluation of the fruit fly retina as a parallel information pre-processor. The light intensity of the original scene is shown on the top left. The red circle indicates the visual aperture of the eye. The logarithm of the original scene is shown on the top right. On the bottom left, “Visual Aperture” shows the projection of the area inside the red circle in the original scene onto the hemispherical visual field. “Input to R1” shows the rate of photons arriving at the R1 photoreceptors. “Delayed by 40 [ms]” shows the “Input to R1” delayed by 40 [ms]. “log(Visual Aperture)”, “log(Input)” and “log(Delayed by 40 [ms])” show the log of the plot in, respectively, “Visual Aperture”, “Input to R1” and “Delayed by 40 [ms]”. Note that “Input to R1” is the actual input to the photoreceptors. On the bottom right, the responses of photoreceptors R1-R6 are shown, respectively, in each block. All hemispheres are viewed orthogonal to their base plane. As a result, they appear to be circular.

The Bionet Group is supported by grants from


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