Our brain – most important control center
Our brain plays a key role when it comes to be mentally fit. It consists of about 100 billion nerve cells. In this unimaginably big network each single nerve cell is connected with other cells via several hundreds and even thousands conjunctions – the so-called synapses. Our total thinking, acting, and feeling but also all our organic and physical processes are directed by transmission of all information via the synapses. Each second, quadrillions of electrical-chemical impulses. During sleep, our brain readjusts billions of its synapses. Only this makes room for our daily new life experiences.
The constant formation, rearrangement and elimination of these synapses increasingly arose the interest of science and brain research. Especially in connection with our sleep and the regeneration and learning ability involved. For a long time, brain research considered that formation of new synaptic connections is a basic prerequisite for learning. Just like in many other fields, too, here an incisive paradigm shift is happening. Because, the exact opposite reveals to be true: the latest findings demonstrate that the nightly degradation of old synapses is the secret of our mental fitness!
Our brain shrinks during sleep
There are still many open questions when it comes to sleep, like “why are we sleeping at all”. But, one thing comes increasingly clear: for our brain, concretely for our nerve cells and synapses as well as their optimal functioning, sleep is essential. Because, exactly during this rest our memories solidify and the things learned during the day are transferred into long-time-memory.
Therefore, it is plausible why we clearly make more mistakes, why our brain fails and why we even tend to false memories when we have a bad sleep or a lack of sleep. Furthermore, people with sleep disturbances and lack of sleep are more prone for stress-symptoms and are more nervous. One simply is not really mentally fit. Measurements of brain waves of people with sleep disturbances and lack of sleep show that their synapses are overactive and therefore not able to further grow. But, especially for good learning results this is a major precondition and would counteract a mental stagnation.
The role of sleep for formation of synapses
Already in 2003, Luisa de Vivo and her team of the University of Wisconsin wanted to know it more exactly and tried to find out what role sleep actually has when it comes to the function of synapses. So, the scientists examined whether the synapses of rested mice differ in size and structure from those that stayed awake. With the help of a high-resolution serial 3D electron-microscopy (SBEM) this was possible. To receive an appropriate result, about 7.000 synapses of the cortex of the animals were tested. And the sensation was perfect: the scientists were able to show that the contact surface of the synapses of the rested mice shrunk about 20 %, on an average!
Read in #3, why our brain needs room during sleep and what “neuronal disposal” means.