The commander of U.S.forces in Afghanistan, General Stanley McChrystal, has urged a dramatic troop increase to combat militants and help stabilize the country.

VOA: standard.2009.10.25

In particular, they increase the amount of norepinephrine, a neurotransmitter that's responsible for just general arousal.

具体来说,安非他命会引起,去甲肾上腺素释放量的增加,去甲肾上腺素,是种负责一般性唤醒的神经递质

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