(c) flickr & tommy_io
記憶力が実年齢より20～30歳も若い，80歳以上の「スーパー高齢者」の脳を対象とした研究が行われた。三次元MRIで平均的な同年代の被験者の脳と50～65歳の被験者の脳の両方と比較したところ，スーパー高齢者の脳は年齢より若く見え，特に通常，加齢により薄くなる皮質の厚さが50～65歳の被験者の脳と同程度だった。皮質の厚さは神経細胞の数の指標になるという。また，注意力に重要な部分，前帯状回は50～65歳の被験者と比べて厚かった。どのように記憶が保たれるかに焦点を当てた今回のような研究が進めば，アルツハイマー病や記憶障害の予防や治療に役立つと考えられる。（吉田素子）
Superager Brains Look, Act Decades Younger
Researchers have long chronicled what goes wrong in the brains of older people with dementia. But Northwestern Medicine researcher Emily Rogalski, PhD, wondered what goes right in the brains of the elderly who still have terrific memories. And, do those people -- call them cognitive SuperAgers -- even exist?
Rogalski’s new study has for the first time identified an elite group of elderly people age 80 and older whose memories are as sharp as people 20 to 30 years younger than them. And on 3-D MRI scans, the SuperAger participants’ brains appear as young -- and one brain region was even bigger -- than the brains of the middle-aged participants.
She was astounded by the vitality of the SuperAgers’ cortex -- the outer layer of the brain important for memory, attention, and other thinking abilities. Theirs was much thicker than the cortex of the normal group of elderly 80 and older (which showed significant thinning) and closely resembled the cortex size of participants ages 50 to 65, considered the middle-aged group of the study.
“These findings are remarkable given the fact that grey matter or brain cell loss is a common part of normal aging,” said Rogalski, the principal investigator of the study and an assistant research professor at the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern University Feinberg School of Medicine.
Rogalski is senior author of the paper, which is published in the Journal of the International Neuropsychological Society.
［単語和訳］
Superager：スーパー高齢者（造語） Brains：脳
Researchers：研究者 have chronicled：記録した goes wrong：おかしくなる dementia：認知症 PhD：博士 terrific：素晴らしい cognitive：認知的
elite：えり抜きの 3-D MRI：三次元磁気共鳴画像法 participants：参加者 brain region：脳領域 middle-aged：中年の
was astounded by：～に仰天した vitality：活力 cortex：皮質
given：～を考えると grey matter：灰白質 brain cell：脳細胞 aging：加齢 principal investigator：研究責任者 assistant research professor：特任講師 Cognitive Neurology：認知神経学 Alzheimer’s Disease：アルツハイマー病
senior author：主席著者 Neuropsychological：神経心理学の（Journal of the International Neuropsychological Societyは雑誌名）
