The group of Prof. Hahnloser is very excited that the paper "Fast Retrograde Access to Projection Neuron Circuits Underlying Vocal Learning in Songbirds" is featured on the cover of the current issue of cell reports. In this study they describe fast and efficient viral vectors to dissect structure and function of neural circuits underlying learned vocalizations in multiple species of songbirds. The AAV variant provides retrograde access to projection neuron circuits including dopaminergic pathways in songbirds, additionally in mice, and allows for retrograde calcium imaging, and multispectral brainbow labeling. One really nice aspect of this study lies in the collaborative effort from within INI (Daniel Düring, Mariana Rocha, Richard Hahnloser, Roman Böhringer, Benjamin Ehret and Benjamin Grewe), with the viral vector facility of the ZNZ (Jean-Charles Paterna and Melanie Rauch), with the Max-Planck Institutes for Ornithology and Neuroscience and the University of Tokyo. https://doi.org/10.1016/j.celrep.2020.108364