I work in drug development within the pharmaceutical industry (also trained in neuroscience, as well as molecular biology), so I understand the moral dilema you are facing.
Personally, I (and I think most within the pharma industry) would rather avoid animal testing if at all possible, for several reasons:
1. It is exploitative and therefore morally questionable, but not necessarily wrong (see below).
2. It is expensive, though not as expensive (in terms of cost, rather than safety) as testing in real people/patients.
3. Results in animals often don't correlate with results in people/patients, especially as animal systems and models of disease are often different to those of humans.
So why do it?
Well, without animal testing, there are limited options:
1. Don't develop any new drugs, despite the acute need for them.
2. Test new drugs directly in humans, given that more than 95% of them will be toxic or ineffective unless the majority are first tested in animals. Would you volunteer given those odds? I guess nobody would, and the regulatory authorities would not even allow it, for our own safety, so the result defaults to option 1.
3. Test new drugs first in the test tube with all the clever systems and technologies we have developed (which we do anyway) and then go directly into humans. However the odds are really no better than option 2 above, so again the result defaults to option 1.
In short, there is no possible way to develop new drugs without first testing in animals, or putting many more humans at risk, so the moral choice is actually very simple, despite any gut emotional reaction to the idea of animal testing.
The only moral question is how much do we really need new drugs. And I think that question can only be answered by those suffering from the disease in question.
I wish we could develop a complete alternative to animal testing, as we would all prefer it, but the fact remains that we just haven't been able to replicate the astonishing complexity of the human body in the test tube. Animals are not ideal models either, but they do replicate some of this complexity and thus help to reduce the huge risk of putting a foreign chemical into a human system.
Finally, I would say this does not give a blanket excuse for animal testing. For example, I am completely against the development of new cosmetics by testing in animals, as if we really needed them, and I find the idea of vanity at the expense of another life abhorrent, even if it's 'just' an animal. Therefore, every individual animal tested and sacrificed should be an individual moral decision. If you are not specifically going to learn something new and more important to mankind than the life of the animal (and you should always ask this question), then the decision is also an easy one. Treat each animal life with respect, and you will sleep well.