生涯しょうがいにおける脳神経接続のうしんけいせつぞくの四大転換期よんだいてんかんき――英えい研究けんきゅうが示しめす発達はったつと老化ろうかの新知見しんちけん

It has been pointed out that the human brain does not remain in a constant state throughout life, but instead undergoes complex and diverse changes.

However, according to a new discovery recently announced by a British research team, it has been found that there are four major turning points in neural connections in the brain throughout life, specifically occurring at the ages of 9, 32, 66, and 83.

These changes are believed to be closely related to significant alterations in brain function.

Previous studies have suggested that the human body as a whole experiences accelerated aging around the ages of 40, 60, and 80, but due to the complexity of the brain, the changes that occur within it have not been fully elucidated.

Although it is already known that different brain regions exchange information via white matter tracts and that these neural connections play an important role in maintaining memory and cognitive functions, much remains unclear about how these structures change throughout the lifespan.

アレクサ・モーズリー氏のケンブリッジ大学の研究グループは、約3人の脳のMRIデータを分析しました。

As a result of a study conducted on 800 people ranging from newborns to 90-year-olds, it was revealed that neural connections in the brain go through five stages throughout a persons lifetime.

From birth to age nine, long and complex white matter tracts are inefficient, and as children grow, unnecessary connections tend to be eliminated.

From age 9 to 32, this trend reverses. Under the influence of hormonal changes during puberty, neural connections become shorter and more efficient, promoting the development of cognitive functions such as planning and working memory.

Furthermore, the period from age 32 to 66 is the most stable, but the effects gradually decline, which may be due to changes in living environment or physical stress.

Between the ages of 66 and 83, connections within the same brain region remain relatively stable, but connections between different brain regions become weaker, which may be a factor that increases the risk of dementia in elderly people.

After the age of 83, neural connections in the brain continue to weaken, and there is an increasing tendency to rely on hubs that connect multiple brain regions.

Mr. Mosley believes that by correctly understanding these transitional stages, it is possible to explain why mental disorders are more likely to develop before the age of 25 and why the risk of dementia increases after the age of 65.

The research group emphasizes that in order to understand abnormalities in mental and neurodegenerative disorders, it is essential to grasp the normal turning points of the brain.

However, they also point out that further research is needed to determine whether these findings apply to different races and regions.