Why do we have less water (80%) than a cucumber (90%) in the brain?!

Question: Why do we have less water (80%) than a cucumber (90%) in the brain?!
- Keywords:
  water
Asked by kaboom2 to Damien, Rachael, Simon, Suzi, Tim on 20 Jun 2011.
- Suzi Gage answered on 20 Jun 2011:
  
  Hi @kaboom2
  I don’t really know WHY, I guess because our brain is a bit more complicated than a cucumber, and has other material in it as well as water.
  
  Also, water and electricity don’t mix very well, so maybe this is why!
  😉

Question: Why do we have less water (80%) than a cucumber (90%) in the brain?!