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Basal ganglia, thalamic and cortical circuitry underlying vocal babbling in the songbird| old_uid | 10037 |
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| title | Basal ganglia, thalamic and cortical circuitry underlying vocal babbling in the songbird |
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| start_date | 2011/05/30 |
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| schedule | 15h-16h |
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| online | no |
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| location_info | Salle de réunion du LNP |
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| summary | Before they develop mature songs, young songbirds produce exploratory vocalizations, or babbling, which are thought to underlie a process of trial-and-error learning. We have recently found that exploratory variability during babbling is actively added to the song by a frontal cortical nucleus that forms the output of a basal ganglia (BG) thalamocortical loop. Using a combination of lesions and electrophysiology in singing juvenile birds, we have examined the roles of the BG and motor thalamus in vocal exploration. We find that the BG-recipient thalamus, but not the BG itself, is required for vocal variability during babbling. During singing, thalamic spike timing is controlled by BG inputs with submillisecond precision, but, surprisingly, song-locked thalamic rate modulations are not driven by BG inputs and even persist following BG lesion. Instead, we find that thalamic rate modulations can be driven by inputs from a primary motor cortical nucleus also necessary for vocal babbling. Together, our data suggest that a reverberant cortico-thalamocortical loop may generate vocal variability during babbling. More generally, these results suggest a role for the thalamus in mediating interactions between frontal and motor cortical areas that drive exploratory behavior during learning.
Joint work with Michale S. Fee |
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| responsibles | <not specified> |
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