Zombie High (1987)

Andrea gets a scholarship to a prep school where only a few girls attend.  Her jealous boyfriend doesn't like that, but at least he doesn't know that one of the professors is interested in her.

The students seem to be kind of lifeless and dull, without any individual personalities.  Andrea figure out this is because the professors are replacing parts of the students brains with a crystal as they need the brain for a serum to retain their youth.

It's a harmless little movie that doesn't specifically have zombies in it.  It's more in reference to the mindless teens due to their partial lobotomies.  One thing that bothered me was that the school has lots of grates in the floors and sidewalks.  All were so flimsy that you'd fall through if you stepped on them.