The nervous system of insects is extremely compact, and might be described as being "hard wired." Nonetheless, this does not preclude rather sophisticated adaptation to provide optimal encoding as a function of stimulus conditions. The present study examined responses of photoreceptors and the output neurons of Drosophila eye, and determined that there is dynamic adjustment of both frequency and amplitude of the output signal that improved sensitivity and increased signal-to-noise ratios. The adjustments include the use of previous encounters with the temporal structure of the images to improve the operating range of the output signal.
