The world is full of authoritative statements about the brain. You lose 10,000 neurons a day. The right brain does this, the left brain does that.
Here is a sentence from a great paper from Brazil [ Proc. Natl. Acad. Sci. vol. 109 pp. 10661 – 10668 ’12 ]
“Despite common remarks in the literature that the human brain contains 100 billion neurons and 10 to 50 fold more glial cells, no references are given to support these statements; to the best of my knowledge they are none other than ballpark estimates.” The authoress gives 3 literature references to such statements. Shockingly, one of them is a textbook by a Nobel Laureate (Eric Kandel) — Principles of Neural Science 4th Edition (2004) p. 20.
Caveat Emptor. Buy lots of salt to keep by your side when you read any great and glorious generalizations about the brain. Notice that we’re not talking about the popular press here.