Left brain cortical activity modulates stress effects on social behavior

Area of Science:

• Neuroscience
• Behavioral Science
• Stress Research

Background:

• The medial prefrontal cortex (mPFC) plays a crucial role in regulating adaptive responses to stress.
• Individual differences exist in how people respond to stress, with some developing maladaptive symptoms and others remaining resilient.

Purpose of the Study:

• To investigate the specific role of medial prefrontal cortex (mPFC) neurons in the left hemisphere in mediating stress-induced changes in social behavior.
• To determine if modulating neural activity in the left mPFC can alter social avoidance behaviors in response to stress.

Main Methods:

• Utilized a mouse model subjected to chronic social defeat stress to induce social avoidance.
• Employed optogenetics to photoactivate or photoinhibit specific mPFC neurons in the left and right hemispheres.
• Measured changes in social behavior and neural activity (firing rates) in response to these manipulations.

Main Results:

• Mice exhibiting stress-induced social avoidance showed decreased neural activity in the left mPFC.
• Photoactivation of these left mPFC neurons reversed social avoidance and restored social behavior.
• In resilient mice, inhibiting left mPFC neurons induced social avoidance, while their normal activity was associated with preserved sociability.
• Modulation of the right mPFC had no significant effect on social behavior.

Conclusions:

• Left hemispheric mPFC neurons critically control the behavioral outcomes of stress, particularly social behavior.
• Depressed neural activity in the left mPFC may underlie the development of maladaptive social behaviors observed in stress-related disorders.
• These findings provide a neural mechanism explaining how stress can lead to maladaptive behaviors, potentially relevant to mood and anxiety disorders.