[Zope] Handling object changes

Hi all, I'm looking for some method to handle changes on my objects. I'm interested in persistence changes. I know I should be able to handle some changes writting a __setattr__ method, but I'm also interested into handle changes even if they are done in a list attribute, or in a dictionary attribute. That's it, I would be able to handle any changed market in the "self._p_changed = 1" way, but I'm not able to find the piece of code doing this work. Anybody knows if it is possible ? If not, anybody knows where is the logic doing this work in Zope (Connection, Storage, Persistence, ...) ? Thanks in advance Santi Camps