Retina Journey: Ganglion Cell Marathon

The retinal signal has reached its final destination before exiting the retina! The Ganglion Cell Layer of the retina is chock-full of its namesake cells, ready to tell the brain what the eye is seeing.

There are over 40 ganglion cells, as well as 60+ amacrine cells, which fine-tune the signal these cells receive. These specialized cells help relay information to over 50 different brain regions where their axons terminate, sending messages about things like brightness, pattern, motion, color, size, shape, and orientation of visual stimuli.

The most studied classes of ganglions include parvocellular (P), magnocellular (M), and koniocellular (K), with parvocellular making up 70% of all ganglions.

Retinal ganglion axons need to be quite long to reach many regions of the brain. They have been found to reach 50 mm (5 cm) in length! The axons exit the eye in a concentrated cluster called the optic nerve before dispersing to the rest of the brain. This area is also known as your “blind spot” because it it reserved for RGC axons only, and no photoreceptors are available in this area.

Once the axons exit the retina, they continue to travel in bundles, which fork at the optic chiasm, and then continue on through the optic tract, before dispersing to various parts of the brain.

It certainly takes a marathon-length of ganglion axon (microscopically speaking) for the signal to travel from the retina to the rest of the brain. So make like an RGC axon, and get ready for our marathon! Join us as we attempt to complete 1 or more retinal cells in under 24 hours. We’ll see you there!

Marathon Instructions:

Starting at 10:00 AM ET on 6/25, you will have 24 hours to complete one or more cells. Bonus & cell renaming information can be found in your in-game notifications.