Inhibitory control of sequential neuronal activity underlying motor output
Final Report Abstract
Sequential activation of neurons has been observed during various behavioral and cognitive processes, but the underlying circuit mechanisms remain poorly understood. Here we investigate premotor sequences in HVC (proper name) of the adult zebra finch forebrain that are central to the performance of the temporally precise courtship song. We use high-density silicon probes to measure song-related population activity, and we compare these observations with predictions from a range of network models. Our results support a circuit architecture in which heterogeneous delays between sequentially active neurons shape the spatiotemporal patterns of HVC premotor neuron activity. We gauge the impact of several delay sources, and we find the primary contributor to be slow conduction through axonal collaterals within HVC, which typically adds between 1 and 7.5 ms for each link within the sequence. Thus, local axonal ‘delay lines’ can play an important role in determining the dynamical repertoire of neural circuits.
Publications
- (2017). EM connectomics reveals axonal target variation in a sequence-generating network. Elife, 6. pii: e24364
Kornfeld J, Benezra SE, Narayanan RT, Svara F, Egger R, Oberlaender M, Denk W, Long MA
(See online at https://doi.org/10.7554/eLife.24364) - (2018). Morphological characterization of HVC projection neurons in the zebra finch (Taeniopygia guttata). Journal of Comparative Neurology, 526:1673–1689
Benezra SE, Narayanan RT, Egger R, Oberlaender M, Long MA
(See online at https://doi.org/10.1002/cne.24437) - (2020). Local Axonal Conduction Shapes the Spatiotemporal Properties of Neural Sequences. Cell, 183:537-548
Egger R, Tupikov Y, Elmaleh M, Katlowitz KA, Benezra SE, Picardo MA, Moll F, Kornfeld J, Jin DZ, Long MA
(See online at https://doi.org/10.1016/j.cell.2020.09.019)
