The reverse-application (using technology to mind control animals) is also a serious research endeavour:
en.m.wikipedia.org
Comment on using rat brains or whatever animal brains for robot control: since the AfD are more technopunk than their Societist counterpart, they will instead use advanced semiconducting and material science to produce artificial brains (called Neuromorphic Computing in real life). In the long run, these artificial brains will outpace natural ones in performance, while being much easier to maintain (hey, you only need to supply them with some electrical power).