"The most interesting thing about heart transplants is that one completely loses his own heart and be replaced with someone else's yet still has the feelings for the same person he/she loves. This proves that love works in the minds of people and not in their hearts. Bottomline is, love is a state of mind. You'll learn how to forget only if you try doing so .." - Dr. Burke, Grey's Anatomy.
Hmmmm ... One does not completely forget love even if he/she tries doing so. Kahlil Gibran once said that love consumes itself. So even if the mind chooses to forget, the heart may continue to remember. And the mind will have no control of it. Even with a different heart.
This is how I see it. "Love is not a function of emotions but the decision of the will". I don't think there are any organs involved. Just soul, spirit, being.