Oooh lovely I couldn't but help to jump in here. I wonder if the start of the thread was inspired by me (?! just a thought) - because I speak on neuroscience in behavioural business contexts. And I use that quote. But also note:
- I state that the brain has 100 billion neurons (most people including all the most respected neuroscientists quote this figure - recent research has shown it to be closer to 85 billion)
- I state that the brain is estimated to have 100 trillion synapses (as many have noted above, neurons can have up to 10'000 synapses). Again as commonly used estimation.
- I state that the "more connections in the brain than atoms in the universe" refers to the number of way the synapses can potentially connect
- I state that I don't know whether it's true or if the calculation is correct (but thank you for the mathematics above)
- I state that is is almost not biologically true in the actual brain because the brains wires in certain ways and not everything is connected to everything and not forgetting that neurons only have one axon and certain neurons are only stimulated by certain neurotrasnmitters, etc.
- I state that I use this figure for representative reasons to illustrate the vast complexity and also magical beauty of the brain and to comprehend what sits in our skulls
So to draw a close to the fascinating discussion I think we can agree
- the brain has 85 billion neurons (for the sake of accuracy 85 not 100)
- the brain has an estimated 100 trillion synapses (will that be revised to 85 trillion in light of the research into numbers of neurons?)
- the brain has in theory more possible connections than atoms (of conventional matter) in the (known) universe
- the brain in reality does not have more possible connections than atoms in the universe much less in fact (but it is a mind-boggingly large number)
Oh and I didn't mention that there are another 85 billion glial cells in the brain which have supportive functions - some research has indicated that these can also transmit information...
All clear now?