Human brain neurons unique
Brain researchers at MIT compared the neurons (brain cells) in the cortex (outermost layer) of the brains of humans with nine other mammals, including two primates.
Neurons transmit signals by opening or closing channels that allow ions such as potassium and sodium to be pumped in or out of the neuron. This pumping through the ion channels requires energy.
In the non-human creatures, they found a close relationship between the size of the neurons and the density of the ion channels, with the density of ion channels increasing with the size of the neurons. However, humans did not fit the pattern; they were quite different. Humans had a much lower density of ion channels than was expected based on the other creatures. This means that humans have a much higher energy efficiency.
“We think that humans have evolved out of this building plan that was previously restricting the size of cortex, and they figured out a way to become more energetically efficient, so you spend less ATP per volume compared to other species,” remarked Mark Harnett, an associate professor of brain and cognitive sciences at MIT.
Notice the language, attributing problem solving to evolution: “figured out a way…”? How can mutations figure out anything? No, this testifies yet again to the uniqueness of mankind, ‘made in the image of God’ (Genesis 1:27), and the supreme skill of the Creator in crafting us.
- McDonnell, S., Researchers find a striking difference between neurons of humans and other mammals, medicalxpress.com, 10 Nov 2021.