英语语法分析

Adenosine normally depresses neuron firing in many areas of the brain.

腺苷通常会抑制大脑许多区域的神经元活动。

During sleep, the number of sites to which adenosine is bound decreases.

在睡眠期间，腺苷结合的位点数量减少。

The chemical adenosine is released by brain cells when those cells are active.

这种化学腺苷是脑细胞活跃时释放的。