Memory and thinking skills naturally slow with age. Scientists are now looking inside living brains to tell if depression might speed up aging. The scientists report that some of the signs they have found are worrying.
Depression has long been linked to some cognitive (认知的) problems. Depression late in life even may increase the risk of developing Alzheimer’s disease. Yet how depression might harm the ability to remember things and think clearly is not known. One possibility: brain cells communicate by sending messages across connections called synapses (突触). Generally, good cognition is linked to more and stronger synapses. With the weakening of cognitive ability. Those connections slowly become less and die. But until recently, scientists could count synapses only in brain cells collected after the person dies.
Yale University scientists used a new method to study the brains of living people. They discovered that patients with depression had a lower density (密度) of synapses than healthy people of the same age. The lower the density, the more serious the signs of depression. Yale University researcher Irina Esterlis says this is especially true of the problem of loss of interest in activities patients once enjoyed. She thinks depression might be speeding up the normal aging.
Esterlis has announced plans for a study of synaptic density on larger numbers of people as they get older, to see if and how it changes over time in those with and without depression. The volunteers would be asked to put a radioactive substance (放射性物质) into their body and this substance links up to another substance in the containers used by synapses. Then each volunteer would be given an imaging test. During the lest, areas with synapses would light up, so researchers would be able to see how many synapses there are in different parts of the brain.
Normal cognitive aging is a process difficult to understand, which refers to other health problems, such as heart disease. It might be that depression does not worsen synaptic weakening. And it could just make the problem more noticeable.
【小题1】The scientists are trying to use living people to research ______.| A．if it’s necessary to study living brains |
| B．why old people are likely to be depressed |
| C．if depression could make people’s brain age more quickly |
| D．signs of people suffering from depression |
| A．It could destroy a lot of brain cells. |
| B．It may slow the development of the brain. |
| C．It could cut off connections between synapses. |
| D．It may harm the cognitive ability by affecting the density of synapses. |
| A．Changes of synaptic density with age. |
| B．Ways to give volunteers imaging tests. |
| C．How to choose suitable people to take part in the test. |
| D．What effects the radioactive substance may have on the test. |
| A．Confident. | B．Objective. | C．Disappointed. | D．Shocked. |
