The lightning, when striking an aircraft, travels as it would on a car or any other conductive material. The electricity travels on the outer surface of the aircraft. Therefore there is no need to protect the objects within the aircraft.
That is if everything works like it is supposed to do, but you never know with lightning, some electrical surge might be present. But I´m not aware of any protective systems. I could imagine there being some kind of protection against electrical surges, protecting the electronics.
(please, correct me if wrong)
The only lightning"rods" I´m aware of are the one´s built in to propeller blades. On the Dowty blades it is actually more of a woven metal strip that runs along the whole blade.