Effects of irradiation on synaptogenesis

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K16690
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Gunma University
• Principal Investigator: Roppongi Reiko 群馬大学, 未来先端研究機構, 助教 (80719857)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 放射線照射 / シナプス / シナプス形態形成 / 細胞死 / DNA 損傷

Outline of Final Research Achievements

Neurons are known to be more radioresistant than glial and vascular endothelial cells. It has been thought that relates to differences in non-dividing and dividing cells. However, both acute and chronic irradiation of the Central Nervous System (CNS) for therapy induces side effects that can cause memory deficits and speech disorders. We analyzed the morphological changes of neurons induced by carbon beam irradiation, which is known to be an effective radiotherapy, in comparison with the already known morphological changes of neurons induced by X-irradiation. Results suggest that carbon irradiation induces cell death but does not affect cell development. Carbon irradiation also affected immature neurons, causing DNA damage and decreased expression levels of synaptic proteins. These results suggest that DNA damage is the trigger for carbon irradiation-induced neuronal dysfunction.

Free Research Field

放射線生物学

Academic Significance and Societal Importance of the Research Achievements

がん患者の増加に伴い、放射線治療は広くわたって知られるようになった今、放射線治療による副作用があることも事実である。様々ながんの中でも脳腫瘍による放射線治療の副作用は極めて重い。副作用は患者の年齢や照射範囲によって個人差はあるが、特に問題となっているのが認知機能障害(高次機能障害)である。しかしながら、脳腫瘍には放射線治療が有効なのが実情。本研究課題、放射線照射による正常の脳神経細胞にどのような影響を与えるのかを明らかにすることで、治療治療の向上や副作用を最小限に抑える治療薬の開発となる基礎研究につながると考えられる。