Hi all, this is my first post here.
Welcome Gordon! I have looked into DaVinci's notebooks, as per your suggestion.
I am not sure who would find this useful or interesting, but there is a doctor who is pretty adamant that this thread that runs from the brain to the bottom of the spine (Reissner's fiber) is responsible for perceptions of divinity. Some have speculated this this is like an antenna for "extra dimensions" or whatever, but I dunno.
"The Heavenly Passage: Known in the West as Reissner's Fiber"
https://www.mdpi.com/2077-1444/13/3/248