Maternal separation early in life induces excessive activity of the central amygdala related to abnormal aggression

• DOI: 10.1111/jnc.16020
• Publication Date: 2023-12-01T08:46:30Z
• Authors: Ken‐ichi Ohta; Chihiro Araki; Hidetoshi Ujihara; Keizo Iseki; Shingo Suzuki; Hikari Otabi; Haruki Kumei; Katsuhiko Warita; Takashi Kusaka; Takanori Miki
• Keywords: Male; Aggression; Rats, Sprague-Dawley; Maternal Deprivation; Central Amygdaloid Nucleus; Animals; Humans; Rats

Abstract Epidemiological studies have indicated that child maltreatment, such as neglect, is a risk factor of escalated aggression, potentially leading to delinquency and violent crime in the future. However, little known about mechanisms by which an early adverse environment may later cause behavior. In this study, we aimed thoroughly examine association between aggression against conspecific animals activity amygdala subnuclei using maternal separation (MS) model, common model life stress. MS group, pups Sprague–Dawley rats were separated from their dam during postnatal days 2–20 (twice day, 3 h each). We only included 9‐week‐old male offspring for each analysis compared group with mother‐reared control group; both groups raised same 2–20. The results revealed exhibited higher excessive central (CeA) among aggressive behavior test. Moreover, significant positive correlation was observed CeA activation. While be involved hunting prey, some previous also relationship intraspecific aggression. It remains unclear, however, whether directly induces Therefore, stimulated optogenetics 8‐week‐old clarify activity. Notably, activation resulted even when opponent animal. particular, bilateral more severe displays than necessary, biting surrendered opponent. These findings suggest development intensifies through activation, can increase escalating