Depression in adolescence, is it because of inflammation in childhood?

▎Editor of WuXi AppTec content team Scientists have noticed in the past that trauma or viral infection before birth or childhood can greatly increase the possibility of mood disorders such as depression or anxiety in adolescence or adulthood
.

 Recently, Chinese scientists published a research paper in Neuron, an authoritative journal in the field of neuroscience, revealing the underlying mechanism
.

Professor Zhang Zhi and Professor Jin Yan of the University of Science and Technology of China and Professor Xu Lin of the Chinese Academy of Sciences have conducted experiments in mice to show why inflammation in childhood promotes depressive symptoms in adolescence
.

The researchers pointed out that if inflammation occurs during the critical time of brain development in the early childhood, it will have a profound impact on the microglia in the brain, making it more likely to be randomly activated by stress events during adolescent development
.

In the experiment, mice developed inflammation due to intraperitoneal injection of lipopolysaccharide (simulating bacterial infection) shortly after birth.
Although they recovered quickly, when they reached puberty, they encountered stressful events (such as weaning, cage separation, noise, fighting, etc.
) , The microglia in the anterior cingulate cortex (ACC) of the brain can easily turn into an activated state
.

 Microglia are immune cells that reside in the brain and act like cleaners to clear faults
.

However, the researchers found that when various stress events continue to occur during puberty, if the microglia of ACC are frequently activated, they will over-clear the dendritic spines of nearby glutamatergic neurons, which are nerve cells that are used to receive nerve signals.

。The device .

As a result, changes in the activation pattern of microglia further lead to the regulation of neural activity, making these neurons maladaptive to stress for a long time
.

Ultimately, due to the impaired ability of the body to cope with stress, it promotes the occurrence of depressive symptoms in adolescence
.

 ▲ Schematic diagram of this study (picture source: reference [1]) The researchers pointed out that the past research on neural circuits mainly focused on the role between neurons and neurons.
However, there are a large number of microglia in the brain What is the role and function of the plasticity of the neural circuit mediated by these cells in the pathological environment is the frontier and hotspot of the current neuroscience research
.

As people have a clearer understanding of the relationship between microglia and the development of depression, the future is expected to bring corresponding diagnosis and treatment methods, so that teenagers and adults can get rid of depression
.

  Source of title picture: 123RF reference materials [1] Peng Cao et al.
, (2021) Early-lifeinflammation promotes depressive symptoms in adolescence via microglialengulfment of dendritic spines.
Neuron.
Doi: https://doi.
org/10.
1016/j.
neuron .
2021.
06.
012[2] Early-life inflammation inducesdepression in adolescence.
Retrieved July 19, 2021 from https:// Neuron | Zhang Zhi/ The Xu Lin/Jin Yan team has made progress in the field of early inflammation-induced depression in adolescence Retrieved July19, 2021 from https://biox.
ustc.
edu.
cn/2021/0709/c635a516958/page.
htm