Thank you!! It took a lot of work...basically I changed every aspect of my application that I could. I'll rattle it off.
I graduated last January, and since then have been working in a well known lab at a top university. I have a publication that I did not have last year. I retook the GRE, and my score improved from 158Q /159V /4 AW to 168Q/ 162V/ 4.5 AW. My undergrad institution was a decent school, but far from top for neuroscience. I did independent research as an undergrad, but didn't have any publications from it. My GPA was and still is a 3.7, though this semester I took a class at the university I work at. I am told that some committees can be very snobbish about which schools people come from, so the class here might have helped combat that attitude (as well as the improved GREs). I definitely have an improved feel for the field now, and think that reflected in my essays and such. Looking back at my SoP from last year makes me cringe a little bit.... I also I think that your application gets better just by applying again, which shows dedication in wanting do science.
Anyway...I think that's everything. I was honestly surprised to receive the interviews that I did. Everyone was sure that I would do fine this time around, but I really thought I was a competitive candidate last year too so all my bets were off.