What classes do you need to prepare you for becoming a NeuroScientist

I guess that would depend on what the Neuroscience program is like at your preferred graduate school. When I was getting my PhD, the program had an undergraduate research program that allowed students interested in grad/med school to come work in the lab. Those students then had a bit of an "in" with the professors. There is a definite aspect of acceptance into a program of someone 'wanting' you to be their doctoral student.