Button Press and release

How can I create a button in maya, and rig it to go into Unity. I am trying to create an effect of the button being pressed. This button is a similar button that you would see on old microwave. I want the button to animate with an indention into it like if a person pushed it. My main problem is that I am trying to animate particular vertices and not one mesh. Can you animate vertices in Unity, and If you can... how?

Yes but.

Using bones in a mnodeling program is far more safe for your sanity, since you can create an actual animation and junk.

If you need to alter vertices in code you can investigate the Mesh class in the scripting reference, but particularly for buttons I highly recommend bones.

Use bones. Weight all vertices of the button to the bone. Animate in Maya, and play the animation in Unity.