I'm currently a software engineer, but I actually majored in Neuroscience in college. Depending on the college you end up going to, you might be able to major in Neuroscience as well! You can probably look up the available majors on the colleges' websites to see if they offer Neuroscience as a major.
If not, then both choices you suggested are good options. Generally, biomedical science majors will have certain anatomy/physiology courses that cover neuroscience and the brain. If they don't, it would be wise to take such courses as electives.
The truth of the matter is, there's no wrong answer when it comes to major. Medical schools don't require you to have a certain major to apply (I know some History majors are are in medical school now). If you decide to become a neurosurgeon later on, you'll definitely get a chance to learn neuroscience in medical school. However, before you enter medical school, you do need to take certain premedical course requirements. And since biological science majors offer these requirements as part of their own requirements, a lot of students seeking to enter medical school end up majoring in biological sciences out of convenience.
This professional recommends the following next steps:
- Take a major that includes courses that cover neuroscience/anatomy/physiology (look at the course catalog).
- If that major does not include those courses, try to take these courses as electives.