
The present invention is concerned with radiolabelled quinoline and quinolinone derivatives according Formula (I-A)* or (I-B)* showing metabotropic glutamate receptor antagonistic activity, in particular mGlu1 receptor activity, and their preparation; it further relates to compositions comprising them, as well as their use for marking and identifying metabotropic glutamate receptor sites and for imaging an organ. ##STR00001## In a preferable embodiment, X represents O; R.sup.1 represents C.sub.1...











