I think that the number of neurons is not the single parameter to take in consideration. At birth the brain is a kind of "soup" made of disconnected neurons - e

I think that the number of neurons is not the single parameter to take in consideration. At birth the brain is a kind of "soup" made of disconnected neurons - except a small kernel structured during the pre-natal life for basic managementof organs. Then repeated external stimuli create connections between neurons, stronger and more complex, leading to a functional brain with memory, "computing" capacities, redundancy, associative capacity. An old brain loses neurons, more and more, but thanks to brain's plasticity and permanent stimuli, it can keep most of its capacities for a long time. The problem is that the small hippocampus is a bottleneck. When it begins to be buried below beta-amiloid and tau-protein, the rest of the brain is still functional but no more reachable. It's the end. It's how I see those things. What do you think of that?