Our brain actively takes sugar from the blood, it's not passive process as pressumed before

Researchers at Technical University of Munich discovered that our brain actively takes sugar from the blood. Prior to this, researchers around the world had assumed that this was a purely passive process. An international team led by diabetes expert Matthias Tschöp reported in the journal Cell that transportation of sugar into the brain is regulated by so-called glia cells that react to hormones such as insulin or leptin; previously it was thought that this was only possible for neurons.
The brain has the highest sugar consumption of all organs and also controls for example hunger feelings. Scientists therefore suspected that a process as important as providing the brain with sufficient sugar was unlikely to be completely random. They were misled by the fact that nerve cells apparently did not control this process and therefore first thought it to occur passively. Then they had the idea that glia cells such as astrocytes, which had long been misunderstood as less important ‘support cells’, might have something to do with transporting sugar into the brain.
The scientists therefore first examined the activity of insulin receptors on the surface of astrocytes, molecular structures which respond to insulin to influence cell metabolism. Here they found that if this receptor was missing on certain astrocytes the result was less activity in neurons that curb food uptake (proopiomelanocortin neurons).
At the same time, adaption of metabolism to challenges like sugar intake became impaired. With the help of advanced imaging technologies such as positron emission tomography, the scientists were able to show that hormones such as insulin and leptin act specifically on ‘support’ glia cells to regulate sugar intake into the brain, like a ‘sugar switch’. Without insulin receptors, astrocytes became less efficient in transporting glucose into the brain, particularly in the area of the satiety centers, which are located in the hypothalamus.
The results showed for the first time that essential metabolic and behavioral processes are not regulated via neuronal cells alone and that other cell types in the brain, such as astrocytes, play a crucial role. This finding could help explain why it has been so difficult to find sufficiently efficient and save medicines for diabetes and obesity until now.

http://www.psypost.org/2016/08/sugar-addiction-discovery-of-a-brain-sugar-switch-44348