Séminaire de Adrienne Fairthall
vendredi 4 février à 14h30
Adrienne Fairthall (Washington )
invitée par Ivo Vanzetta
Online on zoom / on site INT
ID de réunion : 926 9616 6287 ; Code secret : @vBNxSSl45
“Variability, learning and robustness in birdsong”
The songbird zebra finch is an exemplary model system in which to study trial-and-error learning, as the bird learns its single song gradually through the production of many noisy renditions. It is also a sound system to study the maintenance of motor skills, as the adult bird actively maintains its song and retains some residual plasticity. Motor learning occurs by association with timing within the music, represented by sparse firing in nucleus HVC, with motor output driven by nucleus RA. Here we show through modeling that the trim level of the observed variability in HVC can result in a network that is more easily able to adapt to change and is most robust to cell damage or death than an unperturbed network. In collaboration with Carlos Lois’ lab, we also consider the effect of directly perturbing HVC through viral injection of toxins that affect the firing of projection neurons. The song is profoundly affected following these perturbations but can almost perfectly recover. We characterize the changes in song acoustics and syntax and propose models for HVC architecture and plasticity to account for some of the observed effects. Finally, we suggest a potential role for inputs from nucleus Uva in helping to control timing precision in HVC.
- HVC (High vocal center) : is part of the premotor pathway necessary for song production and is also a primary source of input to the anterior forebrain pathway (AFP), a basal ganglia-related circuit essential for vocal learning.
- RA (the robust nucleus of the arcopallium) : HVC project to RA and, in the adult, fire in a rapid burst exactly once during the song.
- Uva (Nucleus Uvaeformis of the thalamus) : sends input to two forebrain nuclei (NIf and HVC) but has not been thought to be important for song production.