Using an approach combining in vivo recordings and optogenetic manipulations in mice, a team of researchers at Inserm led by Cyril Herry succeeded in showing that the inhibition of parvalbumin-expressing prefrontal interneurons triggers a chain reaction resulting in fear behaviour.
Conversely, activation of these parvalbumin interneurons significantly reduces fear responses in rodents.
All observations made by researchers indicate that fear behaviours are controlled in the forebrain at the level of the dorsomedial prefrontal cortex. This control of fear behaviour is based on the activation of neurons in the prefrontal cortex that are in contact with specific areas of the amygdala.
Using an innovative approach combining electrophysiological recording techniques, optogenetic manipulations and behavioural approaches, the researchers were able to demonstrate that fear expression is related to the inhibition of highly specific interneurons-the parvalbumin-expressing prefrontal interneurons.
More specifically, inhibition of their activity disinhibits the activity of the prefrontal projection neurons, and synchronises their action.
The study has been published in the journal Nature.