Unit Test Debugging with Selenium for MVC applicaiton

When trying to debug a unit test, I am able to hit a breakpoint in the test code itself. However, any breakpoints I have set within my MVC application (ie: controller code) are not getting hit. As soon as the test is running, the breakpoints in the MVC application say No symbols loaded. It's not clear to me how Selenium loads the web application. I have a reference to the MVC project in my test code, but it makes no difference. It is clear the assembly is not loaded (as viewed in the Modules window). How can I hit breakpoints outside of the actual unit test project? Simple example, each test performs a login. I add a breakpoint to the validation, and it never gets hit.