Mitochondria metabolic activity influences neurons’ growth rate

Amazing stuff!

"to look at the [mitochondrias]’ respiration rates—basically, how much oxygen they consume, which is also a measure of how much cellular fuel they produce. They used oxygraphy to monitor the oxygen intake of mouse neurons for the first 20 days after their birth—and were stunned to find that after two weeks, the oxygen consumption rate of neurons had grown to nearly ten times that of human neurons.

From there, ... everything fell into place. The team knew they could manipulate mitochondrial respiration pharmacologically, so they sped up metabolism in human cortical neurons in vitro. ... neurons; at only a few weeks old, the accelerated cortical neurons were considerably more mature than a normal human neuron. ...
The scientists tested the same principle in vivo, speeding up the mitochondrial metabolism of human neurons and implanting them into mice, as well as slowing down the mitochondrial metabolism of mouse neurons both in culture and inside the mice’s brains. The results from both in and out of the brain aligned: Human neurons with increased metabolic rates grew faster than normal, and mouse neurons with decreased mitochondrial metabolic rates displayed slower growth. ...
targeting mitochondrial metabolism could one day be considered in the treatment of some developmental disorders ..."

From the abstract:

"Neuronal development in the human cerebral cortex is considerably prolonged compared to that of other mammals. We explored whether mitochondria influence the species-specific timing of cortical neuron maturation. By comparing human and mouse cortical neuronal maturation at high temporal and cell resolution, we found a slower mitochondria development in human cortical neurons compared with that in the mouse, together with lower mitochondria metabolic activity, particularly that of oxidative phosphorylation. Stimulation of mitochondria metabolism in human neurons resulted in accelerated development in vitro and in vivo, leading to maturation of cells weeks ahead of time, whereas its inhibition in mouse neurons led to decreased rates of maturation. Mitochondria are thus important regulators of the pace of neuronal development underlying human-specific brain neoteny."

Mitochondrial Metabolism Dictates Neurons’ Growth Rate | The Scientist Magazine® Altering the rate of respiration in mitochondria changes how fast neurons grow, making mouse neurons grow more like human ones and vice versa, a study finds.

Mitochondria metabolism sets the species-specific tempo of neuronal development (no public access)

A human neuron with mitochondria stained in white