To sleep. Perchance to file? Findings published online this week by the Proceedings of the National Academy of Sciences further support the theory that the brain organizes and stows memories formed during the day while the rest of the body is catching zzz"s.
Gyorgy Buzsaki of Rutgers University and his colleagues analyzed the brain waves of sleeping rats and mice. Specifically, they examined the electrical activity emanating from the somatosensory neocortex (an area that processes sensory information) and the hippocampus, which is a center for learning and memory. The scientists found that oscillations in brain waves from the two regions appear to be intertwined. So-called sleep spindles (bursts of activity from the neocortex) were followed tens of milliseconds later by beats in the hippocampus known as ripples. The team posits that this interplay between the two brain regions is a key step in memory consolidation. A second study, also published online this week by the Proceedings of the National Academy of Sciences, links age-associated memory decline to high glucose levels.
Previous research had shown that individuals with diabetes suffer from increased memory problems. In the new work, Antonio Convit of New York University School of Medicine and his collaborators studied 30 people whose average age was 69 to investigate whether sugar levels, which tend to increase with age, affect memory in healthy people as well. The scientists administered recall tests, brain scans and glucose tolerance tests, which measure how quickly sugar is absorbed from the blood by the body"s tissues. Subjects with the poorest memory recollection, the team discovered, also displayed the poorest glucose tolerance. In addition, their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar.
"Our study suggests that this impairment may contribute to the memory deficits that occur as people age." Convit says. "And it raises the intriguing possibility that improving glucose tolerance could reverse some age-associated problems in cognition." Exercise and weight control can help keep glucose levels in check, so there may be one more reason to go to the gym.
单选题
Which of the following statements is nearest in meaning to the sentence "To sleep. Perchance to file?"?
【正确答案】
B
【答案解析】[解析] 题意：下列哪项叙述最接近“To sleep. Perchance to file?”的意思?
根据文章第二句“findings...further support the theory...”可知科学发现进一步支持当人睡眠时，大脑对白天形成的记忆进行组织和储存这个理论。所以本题选B。
单选题
What is the result of the experiment with rats and mice carried out at Rutgers University?
【正确答案】
A
【答案解析】[解析] 题意：在罗格斯大学以大鼠和小鼠做的实验结果是什么?
由文章第二段第二句“they examined...the somatosensory neocortex...and the hippocampus”可知科学家分析了源自大鼠和小鼠的躯体感觉新皮质层和海马体的脑电波。根据本段倒数第二句“The team posits that this interplay...in memory consolidation. ”可知科学家们认为两个大脑区域的互动是巩固记忆的重要步骤。由此可知A项正确，B项错误。C项和D项内容只是涉及到了实验的过程，未触及到最后的结果。故本题选A。
单选题
What is the relation of memory to glucose tolerance, as is indicated by a research mentioned in paragraph 3?
【正确答案】
D
【答案解析】[解析] 题意：由第三段提到的研究可以表明记忆力与葡萄糖耐受性的关系是什么?
根据文章第三段倒数第二句“Subjects with the poorest memory recollection...displayed the poorest glucose tolerance. ”可知科学家发现记忆力最差的实验参与者显示出最弱的葡萄糖耐受性。故本题选D。
单选题
In what way is memory related to hippocampus shrinkage?
【正确答案】
D
【答案解析】[解析] 题意：记忆力与海马体萎缩有什么联系?
根据文章第三段最后一句“their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar”可知，脑部扫描显示与那些能更好地吸收血糖的人相比，记忆力最差的人的海马体萎缩得要厉害。所以本题选D。
单选题
According to the last paragraph, what is the ultimate reason for going to the gym?
【正确答案】
A
【答案解析】[解析] 题意：根据最后一段，去健身房的最终原因是什么?
根据最后一句“exercise and weight control can help keep glucose levels in check...”可知锻炼身体和控制体重能保持葡萄糖的水平，所以本题选A。