To investigate the intrinsic neural mechanism of aggressive behavior in CD1 mice.

CD1 mice with aggressive behavior were screened out by resident intruder test. After the aggressive conditioned pair preference was further verified, the activated brain regions of the whole brain were labeled with c-Fos, and the types of neurons activated by the aggressive behavior were analyzed by double immunofluorescence labeling. Finally, the effects of activity of these neurons regulated by optogenetics on aggressive behavior were observed.

The c-Fos screening revealed that about 82% of the CD1 mice showed aggressive behavior. After the occurrence of aggressive behavior, the main activation occured in the medial prefrontal cortex (mPFC), and the results of immunofluorescence double labeling showed that the c-Fos positive neurons in the mPFC were mainly glutamatergic neurons. Finally, glutamatergic neurons in the mPFC could be activated by optogenetics, and the activation inhibited the aggressive behavior of CD1 mice. In contrast, optogenetics could inhibit glutamatergic neurons in the mPFC and then promote the aggressive behavior of CD1 mice.

Glutamatergic neurons in the mPFC are an important component in the regulation of aggressive behavior in CD1 mice.