The process of learning well-coordinated motor sequences is an essential aspect of human behavior. Learning to speak, play an
instrument, or swing a baseball bat requires the brain to encode a very specific sequence of motor activity. It is understood at the
descriptive level of analysis the environmental/experiential factors that contribute to learned motor sequences, but there is limited
understanding of the neural modifications underlying such learning. This dissertation explores how auditory experience shapes the intrinsic
physiology of premotor neurons during the process of learning vocal patterns. Understanding these neural modifications could help in
identifying ways to improve learning and identify processes that may account for learning disabilities. The hypothesis tested in this
dissertation is that learning involves plasticity of the intrinsic properties of neurons. This is tested by using in vitro patch clamp
electrophysiology to study the intrinsic physiology of the premotor area HVC, a brain area responsible for the vocal timing of song in zebra
finches. The first set of experiments test whether the intrinsic physiology of HVC changes over song learning and development. The results
show that there are systematic changes in projection neuron physiology as juvenile finches learn to sing. Biophysical models were made to
predict the changes in ion channel expression that underlie the change in physiology. Some observations included alterations in the response
of HVCX neurons to hyperpolarizing current pulses, including model-predicted changes in the Ih current and the T-type Ca2+ current.
Additional changes included a shift in the resting potential of HVCRA neurons. The second set of experiments tests the prediction that
auditory experience drives the observed changes in intrinsic physiology. The results show that tutor-deprivation has a direct effect on the
intrinsic physiology of HVC projection neurons. The results also show that limited tutor exposure can reverse the change in physiology that
resulted from tutor deprivation in a dose dependent fasion. These findings suggest that vocal-motor learning involves not only the alteration
of synaptic weighting between neurons, but also changes in the intrinsic physiology of the component neurons in the circuit. Consequently,
models of vocal learning should account for these intrinsic changes along with changes in synaptic connectivity. More broadly, models of
learning and memory should consider intrinsic plasticity of neurons as a possible contributor to how the nervous system encodes new
information or novel behaviors. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the
degree of Doctor of Philosophy. / Fall Semester 2017. / October 31, 2017. / Includes bibliographical references. / Richard L. Hyson, Professor Directing Dissertation; Richard Morris, University Representative; Frank
Johnson, Committee Member; Richard Bertram, Committee Member; Michael P. Kaschak, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_605010 |
| Contributors | Ross, Matthew T. (author), Hyson, Richard Lee (professor directing dissertation), Morris, Richard Jack, 1950- (university representative), Johnson, Frank (committee member), Bertram, R. (Richard) (committee member), Kaschak, Michael P. (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Psychology (degree granting departmentdgg) |
| Publisher | Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text, doctoral thesis |
| Format | 1 online resource (88 pages), computer, application/pdf |
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