The Effects of Stress on the Brain: Women are more sensitive
by Paola Emilia Cicerone
How does the brain respond when faced with an unexpected event? With a rush of norepinephrine, according to a study by MIT (Massachusetts Institute of Technology). It is a neuromodulator (like dopamine and serotonin), produced in a deep structure of the brain: the locus coeruleus. Norepinephrine can affect large areas of the brain as well, in the study just published in Nature This molecule has been shown to play a key role in mice: helping the brain to learn from unexpected scenarios.
by Paola Emilia Cicerone
The MIT researchers, led by the professor of Neuroscience Mriganka Surfound that, in addition to signaling the surprise effect, norepinephrine helps stimulate the brain and lead it to behavior that leads to a reward, particularly in those situations where this reward is uncertain.
During the experiment, the scientists trained mice to push a lever only when they heard a high-frequency tone: in this case they received water as a reward, but in case of error they were hit by an annoying puff of air. The mice also learned to push the lever harder when the sound volume was louder, while they were more hesitant when the volume was low.
by Gabriele Beccaria
“The animal pushes the lever because it wants a reward and the locus coeruleus provides critical signals to say: push now, because the reward will come – explains Sur -. His team also found that neurons that produce norepinephrine send it to much of the motor cortex, further clue that this signal spurs animals into action.
“Even when performed on mice, the study confirms the central function of norepinephrine,” he explains Daniela Perani, neurologist and neuroradiologist, professor of Neuroscience at the Vita-Salute San Raffaele University of Milan -. The noradrenergic system contributes to attention, vigilance and survival mechanisms. But it also modulates many other systems of the brain, from motor and sensory ones, to cognitive ones, such as memory “.
by Lauro Quadrana *
Previous studies have seen the role of noradrenaline also in neurodegenerative diseases: “In Parkinson’s the neurons of the locus coeruleus degenerate even before those of dopamine, which explains the non-motor symptoms of this disease – continues Perani -. The same degeneration is present in Alzheimer’s disease. Noradrenaline seems to be involved in Attention Deficit / Hyperactivity Disorder (ADHD), so much so that there are already drugs that act on this molecule “.
Finally, it is interesting to note the genetic component of this neuromodulator. Depending on the genes that encode it, the brain can produce more or less. It has been observed that a greater production determines cognitive functions with a poorer performance compared to those who produce less.
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