The effects of fluoride on the central nervous system of the F1 rats by the exposures via placenta, dam's milk, and/or drinking water.

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K21100
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0908:Society medicine, nursing, and related fields
• Research Institution: National Defense Medical College
• Principal Investigator: Suzuki Satoko 防衛医科大学校(医学教育部医学科進学課程及び専門課程、動物実験施設、共同利用研究施設、病院並びに防衛, 衛生学公衆衛生学, 助教 (30821780)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: フッ素 / 二世代曝露 / ラット / 行動学試験 / 記憶学習能力 / 受動的回避試験 / Y字迷路試験 / 脳神経系

Outline of Final Research Achievements

The objective of the study was to clarify the effects of fluoride on the central nervous system of the F1 rats from fetus to the developmental stage by evaluating learning and memory. Fluoride was administered to pregnant rats at 0 or 150 ppm through drinking water. After weaning, the F1 rats were divided into the FF group, which was administered fluoride continuously, and the FC group, which was administered water. F1 rats were maintained until 12 weeks of age and subjected to passive avoidance test and Y-maze test. The significant decrease of the final body weight was observed in the FF group compared to the control group (CC group) and FC group for males and females. In the Y-maze test, the FF group had significantly decreased alternation which related short-term memory than the CC group in males. These results suggest that the continuous exposure to fluoride from the fetal period suppresses growth in both males and females, and impairs short-term memory in males.

Free Research Field

衛生学

Academic Significance and Societal Importance of the Research Achievements

インドや中国において地下水の汚染が大きな問題となっているフッ素について、フッ素の連続曝露が、今まで明らかになっていなかった神経毒性を引き起こすことを示した。ラットでは顕著な成長抑制が観察されたことと併せて、感受性の高い胎児期～発達期のフッ素曝露は脳神経系へも影響を及ぼし、記憶学習能力にリスクがあると明らかにできたことは学術的・社会的意義がある。今回示唆された短期記憶への影響に限らず、疫学研究との所見と併せて研究を進めるべき結果となった。汚染地域における胎児期～発達期のフッ素曝露は、ヒトに対しても成長抑制や神経毒性を示す可能性があり、今後の疫学研究の手掛かりとなり得る。