Fresh forays into fly vision

Flies in the lab get a color TV while researchers watch their neurons fire. Researchers at the UMN devise a new set up to get a deeper look at how flies see color. 
January 27, 2021

Fly eyes play an important role in picking up information about the world around them, finding food and avoiding danger. But before this information can become useful, neural circuits in the brain need to simplify and extract the important components. Within milliseconds these little insects make complex decisions about where to turn, what to eat and what to avoid. 

Color is one piece of information picked up by the eye of the fly. Just like us, flies rely on color to inform them about what is around them.  While we know quite a bit about how human brains process color, how these tiny flies perceive color with much smaller brains is not fully understood. A new set up devised by researchers at the University of Minnesota in a recently published article opens up colorful avenues to gain a deeper insight into fly vision.

Imagine being strapped down in front of a TV while someone looked at how your brain responded to the images on the screen. That’s exactly what the researchers did to flies.  With the advance of technology, researchers have better control of the images and advanced microscopes allowing them to better observe neural circuits responding to these images. 

Until now, we haven’t been able to show the flies colorful images while looking at connections within their brains at the same time. That is because color interfered with the technology within the advanced microscopes capable of imaging neural activity deep within the brain. 

How did they overcome this challenge? They added a custom made filter to the microscope to block the wavelengths of light that interfered with the microscope and at the same time expanded the range of colors they could show the flies. 

New forays into fly vision lay the groundwork for understanding how fly brains process color in a way that is useful to their survival. A deeper look at the world of fruit flies is always more useful since they have complex behaviors that they perform with such small brains and because they share a lot of their biology with humans. —Siddhant Pusdekar

Rachael C. Feord & Trevor J. Wardill. A novel setup for simultaneous two-photon functional imaging and precise spectral and spatial visual stimulation in Drosophila. Scientific Reports. 2020 Sept; 10:15681.