Elevated reactive aggression in forebrain-specific Ccn2 knockout mice

Area of Science:

• Neuroscience
• Molecular Biology
• Behavioral Genetics

Background:

• Cellular communication network factor 2 (CCN2) is a matricellular protein with known roles in connective tissue.
• CCN2 is expressed in the nervous system, but its specific functions in the brain remain largely uncharacterized.
• Understanding CCN2's role in the brain is crucial for elucidating neural communication and behavior.

Purpose of the Study:

• To investigate the function of CCN2 in the brain by examining the behavioral phenotypes of forebrain-specific Ccn2 knockout (FbCcn2 KO) mice.
• To explore the neural mechanisms underlying aggression and anxiety related to CCN2 deficiency in the forebrain.
• To establish a mouse model for studying reactive aggression and potential therapeutic strategies.

Main Methods:

• Generation of forebrain-specific Ccn2 knockout (FbCcn2 KO) mice.
• Assessment of behavioral phenotypes including locomotion, sensorimotor gating, social behavior, anxiety, and reactive aggression.
• Analysis of c-fos expression in aggression-related brain regions (medial amygdala and prefrontal cortex) following the resident-intruder task (RIT).

Main Results:

• Male FbCcn2 KO mice displayed normal locomotion, sensorimotor gating, and social behaviors.
• FbCcn2 KO mice exhibited increased signs of anxiety and elevated reactive aggression.
• RIT-induced c-fos expression was higher in the medial amygdala but lower in the prefrontal cortex of FbCcn2 KO mice compared to controls.

Conclusions:

• Loss of CCN2 in the forebrain, particularly in olfaction-related regions, enhances olfactory social cue signaling in the medial amygdala, leading to increased reactive aggression.
• Reduced CCN2 in the prefrontal cortex may impair inhibitory control and emotion regulation, contributing to anxiety and aggressive behavior.
• The FbCcn2 KO mouse model provides insights into the mechanisms of reactive aggression and potential therapeutic interventions.