Dissertation
Glucose and Serotonin Modulation of Catecholamine Neurons in the Nucleus of the Solitary Tract
Doctor of Philosophy (PhD), Washington State University
01/2015
Handle:
https://hdl.handle.net/2376/117983
Abstract
Catecholamine (CA) neurons in the nucleus of the solitary tract (NTS) are situated in the hindbrain and receive direct peripheral innervation from vagal afferent neurons, which relay information from the gut and cardiovascular system to the rest of the brain. NTS-CA neurons are modulated by a myriad of neurotransmitters and pre- and post-synaptic receptors. This dissertation aims to elucidate the mechanism(s) of action for serotonin and glucose onto NTS-CA neurons, and the impacts a high fat diet has on these mechanisms. First, we found that the 5-HT3R is found on vagal afferents and acts by increasing presynaptic glutamate release onto NTS-CA neurons. Secondly, we discovered that D-glucose effects on NTS-CA neurons occurs via a presynaptic mechanism that is dependent on glutamate release and this is mediated by presynaptic 5-HT3R activity. Third, low glucose concentrations blunted serotonin induced inward currents in nodose ganglia (NG) cells, the cell bodies of vagal afferent fibers. Fourth, glucokinase inhibitors mimic low glucose suggesting a role of glucokinase in glucose sensing. Lastly, we found that the mechanisms behind 5-HT and glucose sensing in NTS-CA neurons did not differ in animals held on a high-fat diet when compared to control animals. These findings contribute to our understanding of an important neural circuit involved in stress, food intake, cardiovascular function, and motivational behaviors.
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Details
- Title
- Glucose and Serotonin Modulation of Catecholamine Neurons in the Nucleus of the Solitary Tract
- Creators
- Brandon Lee Roberts
- Contributors
- Suzanne M Appleyard (Advisor)Jaak Panksepp (Committee Member)James H Peters (Committee Member)Robert C Ritter (Committee Member)Sue J Ritter (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Program in Neuroscience
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 142
- Identifiers
- 99900581531801842
- Language
- English
- Resource Type
- Dissertation