Supported by a scholarship from the Boehringer-Ingelheim Foundation, he went as a post-doctoral researcher to the chair of Prof. Denis Noble, Department of Physiology at the University of Oxford, where - using a combination of experimental and theoretical models - he explored cardiac mechanobiology and heterocellular interactions.

Work from this time ranged from the mechanistic explanation of the Bainbridge effect (mechanically induced increase in heart rate) in isolated pacemaker cells stretched during patch clamp measurements with carbon fibres,[11] the description of a stretch-induced increase in calcium release from the sarcoplasmic reticulum as a mechanism contributing to the Frank–Starling law,[12] to the exploration of direct electrical coupling of cardiac fibroblasts and muscle cells.

[1][2][13] After two decades of research and teaching at Oxford, Kohl was appointed Inaugural Chair in Cardiac Biophysics and Systems Biology at Imperial College London.

Work during this time, funded by the ERC Advanced Grant CardioNECT, focused on the development and use of novel optogenetic and fluorometric techniques,[14] resulting in the first functional demonstration of heterocellular electrical cell coupling in native heart tissue.

[19][20] He served as co-founding director (with Peter Coveney, University College London) of the Virtual Physiological Human Network of Excellence (VPH NoE)[21] and he is the Speaker of the German national collaborative research centre SFB1425 'Make Better Scars'.