Any legitimate research is good research. As a med student you don't have to worry too much about big journals, impact factor, etc. Neuroscience is fair game, especially more basic science stuff (i.e. not the cognitive/behavioral/psychological neurosciences).
Neurosurgery research is a big game for the most part. There is not a whole lot of truly meaningful, original research that will influence the future of the field. Most of it is unfortunately CV building and quantity over quality. For applicants that actually makes things a little easier, because you can churn out a bunch of fluff papers and look pretty good on the interview trail.
There are a few programs that really want accomplished researchers and will drool over applicants with more impressive publications with almost no regard for their clinical acumen or overall performance in med school. This will become even more exaggerated as Step 1 is phased out. These programs tend to be the ones that have strong academic reputations but are known within the field to produce relatively weaker surgeons.