The researchers chose to investigate rats, as social mammals with cerebralactivity that is similar in many ways to that of humans.
研究者们选择了研究大鼠，因为这种具有大脑活动的群居性哺乳动物在很多方式上与人类相似。
2
Such cases are frequent, and it is not necessary that the abnormal cerebralactivity be caused by a physical excitant as in that I mentioned.
这种事例是很常见的，因此不需要考虑我之前提到的大脑产生某种不同寻常的兴奋。
3
In response to external stimuli, dendritic spines in the cerebral cortex undergo structural remodeling, getting larger in response to repeated activity within the brain.