Neuronix has been around longer than I have, but I haven't gotten any wind of any sort of advantage of applying in one grad group or another either. To be clear, Penn hosts MD/PhD interviewees by graduate group. That is, they'll usually have two CAMB groups, a Neuro group, etc.
The amount of applicants and the amount of admitted seem to fluctuate from year-to-year. For gosh sakes, we even have an Epi PhD this year! Also, Penn is pretty good about allowing you to switch once you enter too. I just don't think it's a big factor.
To all those that are coming this week, try to relax and have a good time. I'll be leading a tour, going out to dinner, and hopefully having lunch with you on Friday. 🙂
I also think CaipirinhaQuinho is leading the nightlife group. Oh my!