How much do neuroscientists know about the brain?

Question

How much do neuroscientists know about the brain?

Answer 1

Almost nothing...

Answer 2

A great deal about its structure, development and chemistry, quite a lot about how it responds to external stimuli, and almost nothing about how it thinks.

Answer 3

The amount of peer-reviewed published material concerning the nervous systems of many species, including humans, is vast.  This does not imply that all questions have been answered.  All research that answers a question also leads to further questions.  That's the beauty of science.

Answer 4

I have a 3" thick neural science textbook sitting on my desk next to me, and it's just a small fragment of what we know about the brain.  That said, the brain is still a mysterious organ, and we have a long way to go before we completely understand it.

For example, we know what guides axons to their targets during embryonic development, but we haven't nailed down the steering mechanism within the cell.  We know what regions of the brain do what, but we're not sure how they combine to produce consciousness.  We know why the peripheral nervous system can regenerate, and why the central nervous system can't, but we haven't yet been able to come up with a way to heal spinal damage.