2024届高考英语外刊阅读天天练：阅读理解模拟训练三

高考英语外刊阅读天天练：阅读理解模拟训练三 ① A form of gene therapy that is already being trialled in patients with Parkinson’s disease might provide a one-off treatment for severe alcohol addiction. Alcohol misuse is the biggest risk factor for death, disability and ill health among 15- to 49-year-olds in the UK, responsible for 9,641 deaths during 2021. Like other addictive substances, alcohol triggers the release of a feelgood chemical in the brain called dopamine. However, chronic drinking decreases dopamine release, and people who are addicted to alcohol don’t tend to feel pleasure in drinking it any more. “It seems that they’re drinking more because they feel a need to maintain an intoxicated state,” said Prof Kathleen Grant at Oregon Health and Science University. The idea of the gene therapy was to try to reset this dopamine reward pathway by enhancing the function of brain cells that synthesise dopamine. Like humans, some macaque monkeys are more prone to heavy drinking than others: if you begin to offer them the choice of 5% alcohol alongside their regular food and water, some monkeys will eventually almost always opt for the alcohol. Grant and her colleagues wondered whether resetting their dopamine reward pathways might curb their desire to drink alcohol. To do this, they used a harmless virus to deliver the gene for a protein called glial-derived neurotrophic factor (GDNF) to an area of the brain that is implicated in addiction and reward.“We targeted the cell bodies that produce dopamine with this gene to increase dopamine synthesis, thereby replenishing or restoring what chronic drinking has taken away,” Grant said. The research, which was published in Nature Medicine, found that the macaques permanently started overexpressing dopamine and decreased their subsequent alcohol consumption by up to 90%.“We are entering an era of gene therapy for neurological disorders and perhaps psychiatric disorders, and I think this study is very promising in that direction.” Grant said.