These molecules are secreted into junctions called synapses , where nerve cells abut one another, and when they have done their job they are absorbed back into the cells that secreted them, a process called re-uptake.

• 这类分子被分泌到神经细胞之间相邻的突触连接部位，当它们完成使命后便会通过再吸收作用被吸收回分泌产生了它们的细胞中。