Smoking addiction or abnormal white matter function network

◎ Intern reporter Shen Wei

Physiologically, addictive behavior causes neuroadaptive changes that make people gradually dependent on it. In this process, the brain's reward system and decision-making system play an important role. From a psychological point of view, the causes of addiction often involve emotional and psychological stress.

In April, flowers are in full bloom, and Yang Liu Yiyi, it is the season when some rhinitis patients sneeze continuously. In addition to pollen and willow flots, second-hand smoke also makes rhinitis patients avoid.

In the face of harmful second-hand smoke, people can't help but wonder: why is smoking addictive? Why is it so hard to quit smoking? Scientific research is getting closer to the answer.

Smoking addiction is well known to be one of the global public health threats and a major cause of preventable death and disease in society. Along with cognitive impairment, smoking addiction can lead to lesions of other systems throughout the human body, and damage to white matter structure is one of the core changes in the pathological changes of the smoker's brain.

White matter is a major component of the central nervous system, and white matter is the bridge for brain information transmission. Therefore, studying the changes in white matter function in smokers is of great significance for revealing the neural mechanism of smoking addiction.

Recently, the team of Professor Zhang Xiaochu of the Laboratory of Cognitive Neuropsychology of the University of Science and Technology of China revealed for the first time the abnormalities of the white matter functional network of smokers, and the related research results were published in Psychiatry Research under the title "Changes in the White Matter Function Network in Nicotine Addiction".

Uncover the complex mechanisms behind smoking addiction

"The physiological and psychological mechanisms behind addictive behavior are complex." Zha Rujing, co-corresponding author of the above paper and a special associate researcher in the Department of Psychology of the School of Humanities and Social Sciences of the University of Science and Technology of China, told reporters that from a physiological level, addictive behavior can cause neuroadaptive changes, making people gradually dependent on it. In this process, the brain's reward system and decision-making system play an important role. From a psychological point of view, the causes of addiction often involve emotional and psychological stress. "Many people use addictive behaviors to relieve their discomfort or stress, and some seek pleasure and enjoyment." Cha Rujing said.

The mechanism of smoking addiction is similar to other addictive behaviors. "We all know that the nicotine component in tobacco is the main substance that causes smoking addiction. It stimulates the reward system in the brain while releasing dopamine, which gives smokers a sense of pleasure and relaxation. Cha Rujing said that long-term smoking can lead to tolerance in the human body, which makes smokers need to consume more nicotine to feel the same pleasure.

Smoking addicts have abnormal brain structure and function in several ways. In terms of brain structure, smoking addicts can be manifested as decreased gray matter volume, cortical thickness reduction, white matter structure fibrosis and inflammatory response. Functionally, compared to healthy people, addicts show abnormal functional connections of neural circuits. According to Zha Rujing, a number of previous studies have shown that the structural and functional abnormalities of smokers' brains are closely related to the severity of smoking and the degree of cognitive damage.

Once an addictive behavior is formed, it is difficult to change, and many smokers tend to experience withdrawal symptoms such as anxiety, irritability, and listlessness after trying to quit, which will make smokers choose to smoke again.

In addition to physical addiction, smoking is also associated with emotional and psychological factors. "Many people choose to use smoking to relieve anxiety in life and work, or use smoking as a social and habitual behavior. These can also make people more addicted to smoking. Cha Rujing said.

Smoking addiction or multidimensional brain damage

"In this study, we used functional magnetic resonance to extract the white matter functional signals of the participants, and explored the differences in the topology indicators of the small-world network between smoking addicts and healthy people through the small-world model." Zha Rujing explained that functional magnetic resonance is one of the most commonly used methods to study human brain activity, with good spatiotemporal resolution, high safety, and rich neuropsychological information.

The small-world model is a network model that can reflect the structure and function of the brain in the graph theory analysis method, so the research team uses the small-world network topology anomaly index of smokers' white matter function as feature extraction, and then uses machine learning methods to classify addicts and healthy people.

In addition, the study set up another independent group of participants to model the severity of addiction in smokers.

The research team found that smoking addicts showed a decline in small-world attributes and brain function information separation in the small-world network of whole brain white matter function. The small-world attribute is a topological indicator reflecting brain function, and its decline reflects abnormal brain function, while the decline in brain function information separation ability can cause cognitive impairment. Disorders of the white matter functional network can reflect the severity of a series of neuropsychiatric disorders such as Alzheimer's disease, epilepsy, Parkinson's disease, major depressive disorder, and schizophrenia.

"When the current intervention for the disease is carried out, it is often the changes in the structure of the brain and the functional changes in the gray matter area. This study breaks through the limitations of traditional research focusing on gray matter function, clarifies the importance of white matter functional networks, and shows that brain damage caused by smoking is multi-faceted and multidimensional. Zha Rujing said that this conclusion will provide new intervention ideas for the intervention and treatment of related diseases in the future, and the monitoring of white matter function is also expected to become a key observation indicator.

The results also show that topological abnormalities in the functional network of white matter can be a good biological marker in the classification and diagnosis of diseases. In future studies, it can be further explored whether it reflects the effect of clinical intervention and the outcome of disease. (Science and Technology Daily)