The reason Dr de Quervain suspected the variants might work differently is that the rarer one looks like the commoner one when the latter has a memory-enhancing drug called yohimbine attached to it.

• 多米尼克教授怀疑造成这一现象的原因是两种的基因工作方式可能不同。稀有型[1]看上去就像是普通型与育亨宾®（一种改善记忆药物）的复合物。