Dr Marco Canepari visits Marco Capogna’s lab to optically record back-propagating action potential with calcium and voltage-imaging in interneurons of hippocampal slices. This ongoing collaboration joins visitor’s expertise in high-resolution imaging techniques with the expertise of Marco Capogna on synaptic inhibition and interneuron physiology. Marco Canepari is a senior scientist at the Grenoble Institute of Neuroscience, Inserm, France. His visit to Oxford is supported by a short-term travel grant by the Physiological Society UK.