BEIJING, Feb. 2 (Xinhua) -- A group of Chinese researchers have shown that social isolation triggers "iron accumulation" in specific regions of the brain to induce anxiety, providing inspiration for the development of new interventions for anxiety disorders, according to a study recently published in the journal Cell Metabolism.
In daily life, many people have after prolonged periods of being alone, even without any particular incident occurring, often experienced restlessness and anxiety, and even developed a fear of social interaction. This loneliness-induced anxiety and its underlying biological mechanisms have long perplexed the scientific community.
Researchers from South China University of Technology, east China's Zhejiang University and Southern Medical University in Guangdong Province in south China conducted this study by constructing a mouse model that simulates human long-term isolation.
They discovered that in mice housed alone, the iron content in a brain region called the ventral hippocampus, a sub-region more focused on the regulation of emotions, had demonstrated abnormal iron accumulation.
Further studies revealed that excess iron acts as an erroneous signal, activating a molecule known as iron-α-synuclein (α-Syn), which triggers excessive neuronal firing, like an electrical short circuit continuously sending anxiety alarms to the body.
More importantly, this change precisely targets the emotional center of the brain, causing the brain to mount a highly specific stress response to social isolation.
The study demonstrates that under psychological stress, iron, which helps maintain neural health, can directly drive the remodeling of synaptic structure and function. Termed "ferroplasticity," the mechanism directly links brain iron metabolism disorders to emotional disturbances, shedding new light on the understanding of mental illnesses.
The researchers conducted nasal administration of various agents in mice, targeting molecular iron or α-Syn for intervention. After two weeks of treatment, anxiety behaviors of these mice significantly decreased, and their neuronal activity returned to normal.
The study not only unveils the longstanding mystery of how loneliness affects the brain, but also paves the way for developing novel interventions that are non-invasive, reversible and independent of traditional anti-anxiety medications, said Wang Zhuo, the first and corresponding author of the paper.
Many people in the world suffer from psychological issues related to social isolation. High-risk groups for such problems include elderly people living alone, workers in isolated or confined positions, post-surgical patients and adolescents who socially withdraw. ■
