RT Journal Article
SR Electronic
T1 Long-Term Effects of Repeated Social Defeat Stress on Brain Activity during Social Interaction in BALB/c Mice
JF eneuro
JO eNeuro
FD Society for Neuroscience
SP ENEURO.0068-22.2022
DO 10.1523/ENEURO.0068-22.2022
VO 9
IS 3
A1 Hibiki Okamura
A1 Shinnosuke Yasugaki
A1 Haruka Suzuki-Abe
A1 Yoshifumi Arai
A1 Katsuyasu Sakurai
A1 Masashi Yanagisawa
A1 Hotaka Takizawa
A1 Yu Hayashi
YR 2022
UL http://www.eneuro.org/content/9/3/ENEURO.0068-22.2022.abstract
AB Understanding the long-term effects of stress on brain function is crucial for understanding the mechanisms of depression. The BALB/c mouse strain has high susceptibility to stress and is thus an effective model for depression. The long-term effects of repeated social defeat stress (SDS) on BALB/c mice, however, are not clear. Here, we investigated the effects of repeated SDS in male BALB/c mice over the subsequent two weeks. Some defeated mice immediately exhibited social avoidance, whereas anxiety-like behavior was only evident at later periods. Furthermore, defeated mice segregated into two groups based on the level of social avoidance, namely, avoidant and nonavoidant mice. The characteristic of avoidance or nonavoidance in each individual was not fixed over the two weeks. In addition, we developed a semi-automated method for analyzing c-Fos expression in the mouse brain to investigate the effect of repeated SDS on brain activity more than two weeks after the end of the stress exposure. Following social interaction, c-Fos expression was reduced in several brain regions in the defeated mice compared with control mice. The correlation of c-Fos expression among these brain areas, with exception of the medial prefrontal cortex (mPFC) and central amygdala (CeA), was increased in defeated mice, suggesting increased synchrony. Notably, c-Fos expression in the lateral habenula (LHb) was different between mice that exhibited social avoidance from immediately after the repeated SDS and those that exhibited social avoidance only at later periods. These observations provide insight into the long-term effects of social stress on behavior and brain activity.