Sébastian Fernandez, decrypting the mechanisms of anxiety
- Science and society
- Research
Published on October 23, 2025
–
Updated on October 23, 2025
Dates
on the October 20, 2025
Discover the portrait of Sebastian Fernandez, CNRS researcher, member of the Institut de Pharmacologie Moléculaire et Cellulaire (Université Côte d'Azur, CNRS, INSERM).
His research
At theInstitut de Pharmacologie Moléculaire et Cellulaire (Université Côte d'Azur, CNRS, INSERM), Sebastian Fernandez studies the defense mechanisms developed by the brain to regulate anxiety. Anxiety disorders such as post-traumatic stress disorder, generalized anxiety disorder and panic attacks affect a large proportion of the world's population, with major consequences for individuals and society.
Despite the mechanisms developed by the brain, exposure to stress and other risk factors modifies the activity of neural circuits, increasing anxiety. Theamygdala and nucleus striatum terminale are two brain regions widely studied for their role in detecting danger and triggering anxiety responses such as avoidance, vigilance and freezing (temporary paralysis reaction). Clinical studies using brain imaging techniques have shown that these regions are hyperactive in patients suffering from anxiety disorders. This hyperactivity in these regions may lead to pathological anxiety through mechanisms that remain poorly understood.
At theInstitut de Pharmacologie Moléculaire et Cellulaire (Université Côte d'Azur, CNRS, INSERM), Sebastian Fernandez studies the defense mechanisms developed by the brain to regulate anxiety. Anxiety disorders such as post-traumatic stress disorder, generalized anxiety disorder and panic attacks affect a large proportion of the world's population, with major consequences for individuals and society.
Despite the mechanisms developed by the brain, exposure to stress and other risk factors modifies the activity of neural circuits, increasing anxiety. Theamygdala and nucleus striatum terminale are two brain regions widely studied for their role in detecting danger and triggering anxiety responses such as avoidance, vigilance and freezing (temporary paralysis reaction). Clinical studies using brain imaging techniques have shown that these regions are hyperactive in patients suffering from anxiety disorders. This hyperactivity in these regions may lead to pathological anxiety through mechanisms that remain poorly understood.
To this end, labeling techniques are used to fill the neurons of the ventral tegmental area with a fluorescent marker enabling neuronal connections with the amygdala and the nucleus of the stria terminalis to be followed. In addition, a technique called optogenetics is used to monitor neuronal activity, and has revealed synapses in the ventral tegmental area that activate neurons in the amygdala.
His inspiration
"Other scientists! Science is based on collective progress all over the world, so talking to, seeing and reading other scientists is the main source for pursuing my research."
Results and prospects
The MAC project discovered that synaptic communication between the ventral tegmental area and the amygdala is enhanced by the release of certain compounds such as glutamate and by an increase in a receptor subunit called GluA1. Although these receptors are known to play a role in fear, this is the first time they have been associated with a mechanism of pathological anxiety!
To investigate this further, the team developed a tool capable of blocking the action of these GluA1 subunits in amygdala neurons receiving signals from the ventral tegmental area. This tool has shown that it is possible to reduce the increase in anxiety caused by exposure to social stress.
Research into the amygdala and its neural circuits opens up promising prospects for treating anxiety disorders more effectively. By better understanding the mechanisms of anxiety, it will be possible to develop more targeted treatments, tailored to the specific needs of people suffering from excessive anxiety.
Curious to find out more about the MAC project or Sebastien Fernandez's background?
