Just about all Nikon lenses you'll be wanting to use will employ the F mount, which has been around for more than 50 years.
AI, AI-S, and D types of lenses are all useable with a plain m4/3 to Nikon F adapter.
Newer, G type lenses need a mechanical adapter for aperture control, as they have no ring of their own on the lens barrel.
CX, DX, FX are codes for certain sensor sizes, referenced on modern Nikon digital cameras and lenses. In this case DX (APS-C) and FX (full-frame) are appropriate for adaptation.
CX is the new, small sensor format used in the Nikon 1 series. The lenses for this won't fit a m4/3 mount as their registration distance (between the mount and the sensor) is too short.
