Why we don't need a brain

Last week I had someone on Quora tag me in their question, "When parts of the brain are removed during surgery, is it possible for the remaining brain tissue to expand into the available space?". Yesterday I made an offer on twitter inviting people to ask me some neuroscience questions. Of the responses I got, two were related to the Quora question as well. @a__muse asked: How plastic is a mature brain? and @jsnsndr and @carlacasilli asked: how many neurons can you lose before you (or someone else) notices? viaOscillatory Thoughts: Why we don't need a brain.