Date of Award
1994
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Biological Sciences
First Advisor
Buchanan, James T.
Second Advisor
Eddinger, Thomas
Third Advisor
Fitts, Robert H.
Abstract
In this project I have proposed to investigate the cellular and synaptic effects of dopamine on neurons within the lamprey spinal cord, including those related to locomotor behavior and sensory function, in an effort to further understanding of vertebrate neural network modulation. Dopamine has been shown to strongly affect the spinal locomotor network responsible for producing the neural correlate of swimming (fictive swimming) in lamprey, and dopaminergic cells and fibers have been localized in lamprey spinal cord immunocytochemically. However, the mechanisms by which dopamine modulates this neural output are not known. Therefore the following questions were addressed: 1) Does dopaminergic modulation affect locomotor behavior in intact lamprey? 2) What specific dopamine receptor subtypes are responsible for the effects of dopamine seen during fictive swimming in the isolated lamprey spinal cord? 3) What are the effects of dopamine on the cellular properties of locomotor pattern generating neurons and sensory neurons? 4) Does dopamine affect synaptic interactions between descending reticulospinal axons and motoneurons? 5) Does dopamine modulate synaptic interactions locally within the spinal cord? 6) Are the physiological changes seen following dopamine application sufficient to explain the modification of motor output caused by dopamine during fictive swimming...