It has also been 7-8 years since I took my pre-requisites, or any science courses for that matter. When I decided that I was going to re-apply to medical school I sat down with a professor I got to know pretty well in undergrad. I did research with him for 3 semesters, and he also served as a pre-med advisor for me, as well as many others, in 1994. I spoke with him about whether I should re-take any of these courses or take new science courses before I applied. He thought it was completely unnecessary. However, I had a strong science GPA to begin with and I had received straight As in the prerequisite classes. I think that if you did not perform well when you orginally took those classes or if you had a weak science GPA, taking the prerequisites or other science courses might be in order. I also think it is important you score well in the science sections of the MCAT. I didn't do quite as well as dpark, but I think I scored well enough (10ps, 13bs) to show adcomms I have retained much of the science I knew in
1994-1995.
I did have a conversation with another pre-med advisor who urged me to take some recent science courses. I told her what the first professor told me; namely his reasoning that I already had a strong science GPA as well as solid MCAT scores. She said that although she agreed with his reasoning, she was concerned that some medical schools still might want recent science course work. I chose not to take any more science classes, chiefly because my current job barely gave me enough time to study for the MCAT or volunteer (although I have been slacking big time since I got my August MCAT scores and I expect one of the managing partners to give me a stearn talking to shortly). I hope this helps.
