IIRC myelinated neurons are both more energy efficient taking into account the glial cells and take less space than nonmyelinated neurons if we talk about similar conduction velocities. I’ll have to check this one just to be sure.
The human brain especially has a lot of glia (90% of brain tissue) whereas for a mouse it’s only 65% of brain tissue.
You mean the volume or the number of cells? This is certainly interesting and supports my hypothesis of why rodent neurons grow in size as their brains grow. What do you think?
Why are some brains less myelinated than others? Was their evolution just less lucky?
Possibly, but I’d caution against simplistic evolutionary arguments; evolution is rarely so simple. For instance, chimpanzees have higher axon myelination during development and adulthood than human brains do.
At last, a reply to the interesting stuff! :)
IIRC myelinated neurons are both more energy efficient taking into account the glial cells and take less space than nonmyelinated neurons if we talk about similar conduction velocities. I’ll have to check this one just to be sure.
You mean the volume or the number of cells? This is certainly interesting and supports my hypothesis of why rodent neurons grow in size as their brains grow. What do you think?
Why are some brains less myelinated than others? Was their evolution just less lucky?
Possibly, but I’d caution against simplistic evolutionary arguments; evolution is rarely so simple. For instance, chimpanzees have higher axon myelination during development and adulthood than human brains do.
Perhaps they’re the lucky ones in that particular case. We really can’t assume our brains are the most efficient in all respects.