Supply of Energy Substrate to the Brain

In this book, I have tried to discriminate the contents that most scientists agree with from those parts of the scientist’s share. In this chapter, I will make the points simple; thus, the discriminations may be slightly unclear. Let us start to talk about human adult brain energy metabolism. Neurons depend on astrocytes for a huge energy supply. Neurons receive 30% of their energy from glucose and 70% from lactate. Neurons cannot survive for several minutes without energy supply from astrocytes. The brain has a distinctive energy supply system from other organs, that is, the lactate shuttle and the ketone body shuttle. Neurons are supplied by two energy substrates, lactate, and ketone bodies. Lactate is produced in astrocytes from glucose. “Shuttle” means the lactate transfer system between astrocytes and neurons that makes the transporters so closely located that lactate could move directly from astrocytes to neurons. Recently, the ketone bodies have been working between astrocytes and neurons, known as the “ketone body shuttle.”