blooming…
…starts while we are still in utero, at about 4 weeks of development.
This is when the brain and central nervous system produces the cells that eventually become neurons.
While these are “pre-neurons” at 1 month gestation, by the time a baby reaches 18 months of age, their brains will have created approximately 86 billion neurons, the majority of them before the baby is born.
Another name for this is “Neuronal Proliferation” (because a lot of neurons - estimated to be around 4.6 million per hour - are created.
Blooming also refers to synaptic blooming, which is the development of the communication system (dendrites) between the brain neurons.