The plasticity of the brain defies belief…a woman born without a Cerebellum and not diagnosed till age 24. Which means that even though the genes that would normally be involved in cerebellum development were missing (actually they were there, they were just unable to perform this set of tasks), other genes were able to use other parts of the brain to perform the cerebellum’s tasks. The brain is able to function the way a drummer lays down a complex web of polyrhythms. That is, a drummer has two feet and two hands, but is able to create varying patterns by combining elements of the same hands and foot pedals striking in different but simultaneous patterns. And the brain can use the same neurons in varying patterns by making varying combinations of neurons…a neuron firing can fire off other neurons simultaneously so one neuron can be part of various chains of neurons performing various functions. It’s insanely complex.
I suspect this woman needs more fuel to keep at her peak alertness since a smaller brain means that neurons are firing more often and burning through the cells stores of potassium and manganese (which are what neurons use to spark) than a healthy brain. My wife has recovered remarkably from being without a heartbeat for four minutes, but her thinking fades if she fails to eat properly throughout the day. That’s because she lost a few million neurons when oxygen stopped being delivered to the brain, and since then her brain has recovered most of its former capabilities through plasticity–other neurons taking over. But those neurons are now being used more, which means they are firing more, which means they run low on the fuel–potassium and manganese, mostly–faster than they did prior to her heart stoppage.
A ten year old told me about this story. Brains are so cool, she said.