Terri,
I would offer food for 24 hours then, if they still have not eaten remove the food and wait a couple days before trying again. after 2 weeks I would begin trying some of the more common feeding tricks...isolation feeding, scenting, etc.
If they are available to you, newborn(still sticky and wet) mice sometimes will stimulate a feeding response. Yeh I know sounds gross, but no worse than braining.
Good Luck!