| Neuroscience Cluster
Scientific Retreat Marina Grand Resort, New Buffalo, MI September 10-11, 2007 |
| Sylvan Shank Graduate Student Department of Psychology The role of singing and tutor song exposure in shaping
nighttime sleep activity during early vocal development in the zebra
finch
In mammals, sleep states are associated with neuronal
plasticity subserving learning and memory. In the zebra finch, neural
activity throughout the “song system” is strongly modulated by sleep
and wake states. Cells in the premotor robust nucleus of the
arcopallium (RA), display spontaneous high frequency bursts during
sleep, some of which recapitulate the highly stereotyped premotor burst
patterns observed during singing. Premotor bursting patterns in adult
RA are also particularly susceptible to modification across periods of
sleep. In juvenile zebra finches, behavioral data have also
demonstrated a sleep-dependent component of song learning during the
sensitive period, but the underlying neural mechanisms of sleep in
plastic changes in the song system are unknown. To investigate the
hypothesis that sleep activity in the song system premotor pathway
participates in song learning, we recorded the entire vocal ontogeny of
individual birds, as well as more limited infrared video of sleep
behavior, electroencephalograms and spiking activity of individual
cells in RA in juveniles during nighttime sleep on multiple nights
prior to and following the onset of tutor song exposure. Results from
these experiments demonstrate that bursting activity in RA during
nighttime sleep reflects information specific to the particular song
model a bird is exposed to, is strongly influenced by auditory feedback
during singing, and that RA bursting activity reflects the structure of
the bird’s own vocalizations. As well, the first changes in RA sleep
activity induced by tutor song exposure appear to precede the first
changes in vocal output. These results support the hypothesis that the
widely observed high frequency bursting activity during sleep in the
song system premotor pathway plays an active role in song learning.
08/31/07 |