There are some differences:
- There is only one gate and it cannot be open at will. You cannot learn it by any means possible.
- There are not any levels to it.
- It is more of a study about pain relief and understanding pain.
This theory explains about a pain-modulating system in which a neural gate present in the spinal cord can open and close thereby modulating the perception of pain.
However, if you mean something different than me (as it seems so, but I´m unable to find it), I would like to read about it. This one I know about is "Gate control theory (of pain) by Melzack and Wall. Care to provide a link?