You thought that at XXIe century, the network of highways and national encephalon had all been mapped, properly mapped? Well no. New roads are being excavated. However, the person who has just been brought to light by a team from the Albert Einstein College of Medicine in New York (US) is not a shortcut. In case of dysfunction, it seems to play a crucial role in conditions such as autism, schizophrenia or addiction.
As the magazine reveals science On January 18, researchers trained this path in a much explored area: the cerebellum. Housed at the base of the brain, behind the brainstem in humans, this "mini-brain" (from Latin cerebellum"Small brains") is best known for coordinating movements and maintaining balance and posture. His play is, however, much more complex: in a subtle way he also participates in cognitive functions, especially in language.
Implication of dopamine
In the mouse the New York team is shown, the cerebellum is projected directly (via a single connection) onto a small primitive area of the brain, the ventral tegmental area (ATV). This area belongs to the famous "reward system". Some of his neurons produce dopamine, the messenger that motivates our behavior by creating a sense of pleasure. This area is also involved in addiction. Other neurons indeed carry their surface receptors "opiates". And these set two goals: endorphins, these "lucky molecules" that are produced naturally by the body, but also heroin or morphine.
Let's go back to our cerebellum. Thirty years ago, Early functional neuroimaging studies revealed a surprising response of the cerebellum to cognitive tasks in humans , Says Randy Buckner neuron. An observation that was initially controversial because it obliterated a dogma. But it had to be done: the cerebellum is well activated during non-motor tasks, the subsequent studies showed.
"In 1998, world specialist Jeremy Schmahmann of the Harvard Medical School unveiled the importance of the cerebellum in the treatment of executive functions. [planification, flexibilité mentale…]. This, especially in behavior that is reinforced by a reward "says Michel Thiebaut de Schotten, researcher neuroimaging at the ICM (CNRS, Sorbonne University, Pitié-Salpêtrière hospital), in Paris.