【英语时差8，16】自杀

 In the United States someone attempts suicide every minute. In a single day roughly eighty Americans kill themselves. What compels so many people to end their lives prematurely¹?  Countless elements factor into the fatal decision that leads to suicide. In recent years, however, scientists have been searching for an underlying² biological explanation. Although not conclusive³, the most compelling evidence points to irregularities in a brain chemical called serotonin.

Serotonin is a neurotransmitter, meaning that it travels between neurons in the brain to relay chemical messages. When neurons communicate they release serotonin into the space between neurons called the synapse⁴. After the serotonin has delivered its message, the neuron sending the serotonin reabsorbs the chemical. Besides working as a chemical messenger, serotonin seems to sooth the mind. Antidepressant drugs such as Prozac work by causing serotonin to remain in the synapses⁵ longer before being reabsorbed, thus having an even greater calming effect.

Several studies have linked suicide to low levels of serotonin in the brain. Scientists have determined⁶ that the brains of at least some suicide victims had tried to horde⁷ serotonin by not allowing it to be reabsorbed into the synapse. While low serotonin levels alone do not cause someone to commit suicide, they seem to play an important role.

Although lithium in pill form is a proven suicide deterrent⁸, many at-risk patients shun⁹ the drug due to side effects including hand tremors¹⁰, thirst, and weight gain.  

1 prematurely   

adv.过早地，贸然地

参考例句：

• She was born prematurely with poorly developed lungs. 她早产，肺部未发育健全。 来自《简明英汉词典》
• His hair was prematurely white, but his busy eyebrows were still jet-black. 他的头发已经白了，不过两道浓眉还是乌黑乌黑的。 来自辞典例句

2 underlying   

adj.在下面的，含蓄的，潜在的

参考例句：

• The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
• This word has its underlying meaning.这个单词有它潜在的含义。

3 conclusive   

adj.最后的，结论的；确凿的，消除怀疑的

参考例句：

• They produced some fairly conclusive evidence.他们提供了一些相当确凿的证据。
• Franklin did not believe that the French tests were conclusive.富兰克林不相信这个法国人的实验是结论性的。

4 synapse   

n.突触

参考例句：

• The chemical floods the synapse, overwhelming the serotonin receptors.这种化学物质湮没了突触，覆盖了5--羟色胺的受体。
• Ecstasy also keeps serotonin from being reabsorbed,further increasing the concentration in the synapse.毒品引起的狂迷还能阻止5--羟色胺的再吸收，进一步增加了突触内5--羟色胺的浓度。

5 synapses   

n.（神经元的）突触( synapse的名词复数 )；染色体结合( synapsis的名词复数 )；联会；突触；（神经元的）触处

参考例句：

• Nerve cells communicate with one another at the synapses, where their membranes almost touch. 神经细胞在突触部位彼此沟通，在这里它们的膜几乎接触到一起了。 来自辞典例句
• Glutamatergic synapses are common excitatory chemical connections in mammalian central nervous system. 谷氨酸性突触是哺乳动物神经系统的主要兴奋性突触。 来自互联网

6 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

7 horde   

n.群众，一大群

参考例句：

• A horde of children ran over the office building.一大群孩子在办公大楼里到处奔跑。
• Two women were quarrelling on the street,surrounded by horde of people.有两个妇人在街上争吵，被一大群人围住了。

8 deterrent   

n.阻碍物，制止物；adj.威慑的，遏制的

参考例句：

• Large fines act as a deterrent to motorists.高额罚款是对开车的人的制约。
• I put a net over my strawberries as a deterrent to the birds.我在草莓上罩了网，免得鸟歇上去。

9 shun   

vt.避开，回避，避免

参考例句：

• Materialists face truth,whereas idealists shun it.唯物主义者面向真理，唯心主义者则逃避真理。
• This extremist organization has shunned conventional politics.这个极端主义组织有意避开了传统政治。

10 tremors   

震颤( tremor的名词复数 )； 战栗； 震颤声； 大地的轻微震动

参考例句：

• The story was so terrible that It'sent tremors down my spine. 这故事太可怕，它使我不寒而栗。
• The story was so terrible that it sent tremors down my spine. 这故事太可怕，它使我不寒而栗。