When I took on the task of counting up all the brain’s fibers and figuratively laying them end-to-end, I had a sense that it would be relatively easy–do a bit of strategic Googling, check out
The human brain’s approximately 86 billion neurons are probably connected by something like 850,000 km of axons and dendrites. Of this total, roughly 80% is short-range, local connections (averaging 680 microns in length), and approximately
