In November 1970 he took over as Secretary for Sciences, Humanities and Arts ("Sekretär für Wissenschaft und Kultur") with the party sectional leadership team ("SED-Kreisleitung") at the Karl Marx University. That lasted till December 1977 when he took over as Party Regional Secretary for Sciences, Humanities, Popular education and Arts ("Sekretär für Wissenschaft und Kultur") in respect of the Leipzig party regional leadership team ("SED-Bezirksleitung"). By this time, seven years after receiving his doctorate, he had received his Habilitation for a piece of work on the postwar history of Leipzig University. Identified as a post-graduate student of significant promise, during 1982/83 he accepted the opportunity to study for a year at the Academy for Social Sciences run in Moscow by the Central Committee of the Soviet Communist Party. His lecturers in Moscow included the reformist historian Roy Medvedev who would emerge after 1991 as a leading proponent of Democratic socialism. Responding to an interviewer's question in 1990 Keller acknowledge that even as far back as 1982/83, when he was studying in Moscow, gentle breezes of what came to be known as Glasnost were already discernible in the Soviet capital, both one or two theatres and in some of the (little noticed by foreign observers) activities of Mikhail Gorbachev at the Agriculture Plenum of the Central Committee's Secretariat for Agriculture.