Can neural connections in the brain be simplified?
I know that when neurons die in our brain, there is a process of neuroplasticity, when neurons become more complex, creating new connections, and replace their dead neighbors. If there are somehow more neurons than there were, will the old neurons be simplified by distributing their connections with the new neurons? Thanks.
As far as I know, this process has never been observed. The number of neurons increases in childhood, but their functions also increase. When the brain has grown, it is no longer necessary to destroy existing connections, even if new neurons appear. Such destruction can lead to impaired brain function.
Each neuron in the brain occupies a certain place and has contacts with certain neurons, too. Some neurons have more of these contacts, while others have fewer, but there are many of them. And all the time, while the brain is alive, some of the contacts are breaking up, but all the time new ones are being formed. And it seems to me that this process is in a kind of equilibrium, i.e. the number of interneuronal connections fluctuates relative to some constant value.
Hence the conclusion. When a neuron dies, its neighbors take over its functions, and the number of contacts can only increase. So no simplification is out of the question.
However, the aging process is accompanied by mass death of neurons. As a result, the total number of contacts decreases over time. Neighbors can no longer fully assume the functions of dead cells. And I do not know what happens to the dynamic constant around which the number of synapses fluctuates. It is possible that disorders such as dementia are associated with a reduced neuropil.