With this method, they've been able to develop medication for a few diseases that save thousands to tens of thousands of humans a year (related to epilepsy).
Is it wrong?
Morally, more people are saved from this experiment, than the rats that gave their lives and far more "suffering" has been removed. On the other hand, that depends on your moral code. For me, it's about "what helps / makes me suffer less (short and long-term", so I think it's fine! For others, it's society, it's about the net positive for society - for them it's also fine. So, really, it's just those who empathize with the animals; which I think we all do, we just balance the perspective.
Personally, I couldn't do it, but I support the net gain to society.
That's not the biggest difference though. The elephant in the room is that animals are not humans, and they are worth less than humans. Else, why not use humans?
Dogs are probably the most humane treated animals on the planet. I wish other animals got the similar treatment as well.
Would love to read some of those debates. Don’t get me wrong. I am in support for using mice for medical reasons.
I have a friend who raises mice and then has to break their necks to euthanize them before experimenting on them. Another of my friends has to give mice cancer.
The former friend's lab has come up with life-changing treatments for muscular diseases, and the latter friend is helping to develop immunotherapy methods.
While it's awful to think about the price, it's important to think about why the price is paid and how much suffering can be prevented.
Another note: there are strict codes of ethics for how animals are treated in labs, so in most reputable organizations, the suffering is as minimal as possible (sometimes no suffering at all).