NYU Neuroscience Institute and Department of Otolaryngology, New York University Langone Medical Center, New York, United States; Center for Neural Science, New York University, New York, United States
Rajeevan T Narayanan
Computational Neuroanatomy Group, Max Planck Institute for Biological Cybernetics, Tübingen, Germany; Bernstein Center for Computational Neuroscience, Tübingen, Germany; Center of Advanced European Studies and Research, Bonn, Germany
Fabian Svara
Max Planck Institute of Neurobiology, Martinsried, Germany
NYU Neuroscience Institute and Department of Otolaryngology, New York University Langone Medical Center, New York, United States; Center for Neural Science, New York University, New York, United States
Marcel Oberlaender
Computational Neuroanatomy Group, Max Planck Institute for Biological Cybernetics, Tübingen, Germany; Bernstein Center for Computational Neuroscience, Tübingen, Germany; Center of Advanced European Studies and Research, Bonn, Germany
NYU Neuroscience Institute and Department of Otolaryngology, New York University Langone Medical Center, New York, United States; Center for Neural Science, New York University, New York, United States
The sequential activation of neurons has been observed in various areas of the brain, but in no case is the underlying network structure well understood. Here we examined the circuit anatomy of zebra finch HVC, a cortical region that generates sequences underlying the temporal progression of the song. We combined serial block-face electron microscopy with light microscopy to determine the cell types targeted by HVC(RA) neurons, which control song timing. Close to their soma, axons almost exclusively targeted inhibitory interneurons, consistent with what had been found with electrical recordings from pairs of cells. Conversely, far from the soma the targets were mostly other excitatory neurons, about half of these being other HVC(RA) cells. Both observations are consistent with the notion that the neural sequences that pace the song are generated by global synaptic chains in HVC embedded within local inhibitory networks.
