I’ve wondered that for a long time. What is it about the brain that makes it the most complex piece of tissue possibly in the whole universe?

What is it about that 3lb slab of pink flesh?

I think I’ve found the answer in Principles of Neural Science, pg. 41:

“The brain expresses a greater number of genes than any other organ in the body, and within the brain diverse populations of neurons express different groups of genes.”

 And that’s why the brain is the most complex organ in the body. It expresses lots of different genes and different neuronal populations express certain genes! (Or that’s part of the answer why I guess…”