Fast Retrograde Access to Projection Neuron Circuits Underlying Vocal Learning in Songbirds
Daniel N. Düring, Falk Dittrich, Mariana Diales Rocha, Ryosuke O. Tachibana, Chihiro Mori, Kazuo Okanoya, Roman Boehringer, Benjamin Ehret, Benjamin F. Grewe, Stefan Gerber, Shouwen Ma, Melanie Rauch, Jean‐Charles Paterna, Robert Kasper, Manfred Gahr, Richard H. R. Hahnloser
Abstract
Understanding the structure and function of neural circuits underlying speech and language is a vital step toward better treatments for diseases of these systems. Songbirds, among the few animal orders that share with humans the ability to learn vocalizations from a conspecific, have provided many insights into the neural mechanisms of vocal development. However, research into vocal learning circuits has been hindered by a lack of tools for rapid genetic targeting of specific neuron populations to meet the quick pace of developmental learning. Here, we present a viral tool that enables fast and efficient retrograde access to projection neuron populations. In zebra finches, Bengalese finches, canaries, and mice, we demonstrate fast retrograde labeling of cortical or dopaminergic neurons. We further demonstrate the suitability of our construct for detailed morphological analysis, for in vivo imaging of calcium activity, and for multi-color brainbow labeling.