科學(xué)家報告說,，鍛煉可以幫助恢復(fù)干細(xì)胞的生長,，而且可以改善大腦被臨床劑量的輻射損傷的年輕小鼠的注意缺陷行為,。目前，許多接受腦瘤放射性療法的人類青少年后來出現(xiàn)了可能與注意缺陷有關(guān)的學(xué)習(xí)和記憶問題,。這些問題與輻射有關(guān)聯(lián),，后者不但可以殺死癌細(xì)胞，也可以傷害海馬區(qū)的干細(xì)胞,。
海馬區(qū)是一個對于工作記憶至關(guān)重要的區(qū)域,。Georg Kuhn及其同事讓出生9天的小鼠暴露在相當(dāng)于人類癌癥患者接受的輻射劑量下。讓其中一半的小鼠能使用一個轉(zhuǎn)籠,。在13周的時候,，這些小鼠被放置在了一個開放空間中，同時這組科學(xué)家分析它們運動的模式,。4周之后,，這些小鼠被殺死，對它們的大腦中的新生干細(xì)胞和神經(jīng)元進(jìn)行了檢查,。這組科學(xué)家發(fā)現(xiàn)進(jìn)行了鍛煉的小鼠的大腦含有的干細(xì)胞比沒進(jìn)行鍛煉的小鼠多大約50%,，而且這些干細(xì)胞發(fā)育成神經(jīng)元的可能性更高。這組作者提出,，鍛煉可能在一定程度上逆轉(zhuǎn)兒童患者的大腦輻射損傷,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS published ahead of print September 2, 2008, doi:10.1073/pnas.0711128105
Voluntary running rescues adult hippocampal neurogenesis after irradiation of the young mouse brain
Andrew S. Naylor, Cecilia Bull, Marie K. L. Nilsson, Changlian Zhu, Thomas Bj?rk-Eriksson, Peter S. Eriksson, Klas Blomgren, and H. Georg Kuhn
Cranial radiation therapy is commonly used in the treatment of childhood cancers. It is associated with cognitive impairments tentatively linked to the hippocampus, a neurogenic region of the brain important in memory function and learning. Hippocampal neurogenesis is positively regulated by voluntary exercise, which is also known to improve hippocampal-dependent cognitive functions. In this work, we irradiated the brains of C57/BL6 mice on postnatal day 9 and evaluated both the acute effects of irradiation and the effects of voluntary running on hippocampal neurogenesis and behavior 3 months after irradiation. Voluntary running significantly restored precursor cell and neurogenesis levels after a clinically relevant, moderate dose of irradiation. We also found that irradiation perturbed the structural integration of immature neurons in the hippocampus and that this was reversed by voluntary exercise. Furthermore, irradiation-induced behavior alterations observed in the open-field test were ameliorated. Together, these results clearly demonstrate the usefulness of physical exercise for functional and structural recovery from radiation-induced injury to the juvenile brain, and they suggest that exercise should be evaluated in rehabilitation therapy of childhood cancer survivors.
