Hi,
I don't think there is a specific list of brain structures that one is expected to know for the MCAT.
It's hard to say without context, but I find for the bio approaching things by memorizing a list didn't work for me as well as just reading and learning new content - if you look at the context of the AAMC section summaries (https://students-residents.aamc.org/applying-medical-school/article/whats-mcat-exam/), the focus of a lot of biological systems is to understand how they work together.
What you could do to familiarize yourself with more structures in the brain is search up nervous system in the Bio section pdf and learn more about the specific subsections that the MCAT syllabus describes.
I apologize that I don't have a more direct answer, I hope this helps and perhaps another instructor could weigh in with more specific information.