Although the brain only has 2% of body weight, it consumes 20% of the energy that the whole body spends. However, neurons do not need as much energy as they thought to transmit the electrical signal.
In fact, for many years researchers have recognized the model of Hodgkin and Huxley, two physiologists who received the Nobel prize in 1963 for their work on the electric transmission of neurons. According to this study, the effectiveness of transmission within neurons was 25-30%.
However, some scientists suspected that efficiency should be greater. Among them are Henrik Alle and his colleagues at the Max Planck Institute for Brain Research. Thus, the effectiveness of the transmission of electricity within the neurons of centers related to memory and learning has been analysed, demonstrating that it is 2-3 times higher than that provided by the model. That is, the efficiency of the process is 70-80%.
In addition, it explains why the difference is so big. When modeling, it was thought that negative and positive ions faced each other in neurons. Now, however, they have seen that the potassium ion does not begin to penetrate until the sodium ion comes out. In this way the transmission is much more effective.
And what does the brain spend the rest of the energy? According to Allen, half is kept alive for neurons and everything else doing operations. In addition, he believes that he spends more on neuronal transmission than on the inside of neurons.