Congrats on your acceptances!
Missouri is definitely not a blue state, but St. Louis and the wider metropolitan area is surprisingly diverse and left-leaning. (And the WashU community even more so, with many URM students, deans, and physicians.) With your interest in the neuroscience, it would be hard to pass it up - one of the strongest neuroscience programs in the country with SO MANY PIs - and internal transfers into the MSTP (one of the largest in the country, so you'll have lots of friends and support!) is very common - several students in my class have. And if you don't want to commit to a PhD, finding funding for research, whether during the academic year or a year off, is extremely easy and well-facilitated.
And if you're perhaps interested in either matching neurology or neurosurgery, our matches this year were:
Neurology
Harvard/BWH
Harvard/BWH
NYP/Columbia
NYU
Stanford
UCLA
UCLA
UCLA
U Washington
Neurosurgery
Harvard/MGH
Johns Hopkins
WashU/Barnes-Jewish