In our brain we have 80 billion (older text books often mention 100 billion) information processing cells: neurons (from the Greek word for string), of some 10,000 different types. Each neuron cell functions like a small computer or microprocessor processing electrical signals. At the same time each cell is also acting as a chemical factory, sending chemical signals to other cells. These chemicals are called neuro-transmitters: they transmit messages from one neuron to another. The cells influence each other and the connections between other cells. An important neuro-transmitter is dopamine, which among other things gives us a feeling of excitement. Others are similar to opium, which among many other things kills pain and gives us a feeling of satisfaction. We will discuss these later to better understand why it is so difficult to disconnect from the Internet and why many people become really addicted to it.
Our brain also has some 80 billion Glia cells. Until recently scientists thought that the Glia cells only provided structural support, metabolic support, insulation and a matrix for development. Since our neurons are not regularly replaced like most other cells in our body, they have to be kept in shape and nurtured caringly by these Glia cells. Now scholars are beginning to discover that these cells also play a role in the information processing of our brain because they influence the connections between the neurons. These Glia cells also control waste management. You can easily imagine how very important this is given that the brain cells produce and release chemicals all the time. Most of this waste management happens during sleep. If there is enough interest in this blog, I am willing to explain this later. Let me know.
In my next blog I will explain the computing power of our brain. Prepare yourself for huge numbers. Maybe you can try a guess: 80 billion neurons, have between 1,000 and 400,000 connections each that fire up to 500 times/second. Do the math to find out how many possible combinations this gives.
 Targeting Glia Cells: Novel Perspectives for the Treatment of Neuro-
psychiatric Diseases. B. Di Benedetto and R. Rupprecht; Current Neuropharmacology, 2013, 11, 2