Considering that the aerobic energetic landscape of the brain is shaped by its mitochondria,
Mosharov et al. generated an atlas of mitochondrial content and enzymatic OXPHOS activities
at a resolution comparable to MRI by physically voxelizing frozen human brain tissue.
However, astrocytes in the adult human brain lack expression of several TCA cycle
and OXPHOS enzymes. Therefore, their formula expressing mitochondrial respiratory
capacity (MRC) -defined as tissue respiratory capacity normalized to mitochondrial
density- underestimates actual values by a factor proportional to the square root
of the fraction of respiration-capable cells (primarily neurons) in gray matter voxels.
