Question: How small can the blood vessels in our retinas get?
Answer: Smaller than the diameter of a red blood cell (~6-8µm wide).
The red blood cells have to fold themselves to get through the tightest of spaces and line up, single file to get through the smallest retinal capillaries.
There are lots of data encoded in our connectomes, not just neurons. We spend lots of time exploring and examining glia and vasculature in the retina along with the neurons. This is one example of a small capillary in the retina that is so small, that the red blood cells have to fold themselves to get through.
Nice image. Connectomes are fascinating. Did you or someone else add color to the RBC’s? If so, how is that done? Since the structure is so small, is it possible a sectioning artifact could be responsible for the folding?
I added false color to the RBCs in Photoshop. Folding, or nano-folding is always possible with sections this thin (70-90nm), but this section is pristine.
Thanks for the informative reply Bryan. Your addition of color really helped to illustrate your point. Once again, very nice image that is also educational.
Thanks Bill!