SORU: aşağıdaki parçaya göre cevaplayınız
The underlined phrase in the passage ‘switched on’ is closest in meaning to ----.
Fasting could boost your brainpower. A stomach
hormone that stimulates appetite seems to promote the
growth of new brain cells and protect them from the
effects of ageing ─ and may explain why some people
say that fasting makes them feel sharper. Ghrelin is
known as the hunger hormone, as it is made by the
stomach when it gets empty. If we go a few hours
without food, its levels rise in our blood. But there is also
evidence that ghrelin can enhance cognition. Animals
fed reduced-calorie diets have better mental abilities.
Injecting ghrelin into mice improves their performance in
learning and memory tests, and seems to boost the
number of connections in their brains. Now Jeffrey
Davies at Swansea University, UK, and his team have
found further evidence that ghrelin can stimulate brain
cells to divide and multiply, a process called
neurogenesis. When they added the hormone to mouse
brain cells grown in a dish, it switched on a gene
known to trigger neurogenesis. ‘’If the same happens in
animals, this could be how ghrelin affects memory,’’
says Davies, whose work was presented at the British
Neuroscience Association conference in 2017. The work
may have implications for treating neurodegenerative
conditions. Davies’s team have found that ghrelin, or
chemicals that act the same way, could help treat some
conditions like Parkinson’s disease.