How to change a WPF control's visibility from ViewModel

I've an WPF application where tried to implement MVVM pattern and Prism 2. I have a Usercontrol which has subscribed to an event fired from another Usercontrol. I would like to toggle visibility of few child elements in the subscribing control. Events are fired properly, even I am successfully able to bind data to some elements. How do I bind Visibility or any style property for that matter with the ViewModel and change them dynamically.