Hindbrain glucagon-like peptide 1 (GLP-1) neurons project to numerous forebrain areas, including the lateral septum (LS). Here, we propose this pathway represents a direct link between satiation processing and food reward, as LS-projecting GLP-1 neurons directly connect vagal afferent signaling to a reward-related brain region. The four studies presented in this dissertation broadly address the contribution of LS GLP-1 receptors (GLP-1R) in the control of feeding behavior under both non-stressed and stressed conditions in rats and mice. We first confirmed that pharmacologic activation of LS GLP-1R suppresses feeding. When we blocked these receptors rats and mice, we found that endogenous activation of LS GLP-1R promotes satiety. Because the LS is known to play a role in motivation, we next investigated the role of LS GLP-1R in motivation for food by examining operant responding for sucrose on a progressive ratio (PR) schedule. Our findings here suggest that GLP-1R in the dorsal subregion of the LS (dLS) affect motivation for food in both rats and mice. While we initially focused on the role of GLP-1 under normal, non-stressed conditions, central GLP-1 is also involved in behavioral and endocrine responses to stress. Here we demonstrated for the first time that restraint stress robustly activates hindbrain GLP-1-producing neurons in mice and found that LS GLP-1R blockade attenuates 30-min restraint stress-induced hypophagia in both rats and mice. LS neurons project to several other brain regions known to play a critical role in the control of food intake. In the final study, we determined the distinct axonal targets of LS GLP-1R bearing neurons. This anatomical analysis begins to unravel the downstream circuitry of GLP-1 signaling in the LS and has revealed candidate neural pathways through which LS GLP-1 signaling may alter food intake and other behavioral responses to stress. Together, the results presented in this dissertation provide clear evidence that there is in fact significant overlap in the neural pathways that mediate satiation signaling and food reward. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2019. / February 27, 2019. / food intake, food reward, glucagon-like peptide 1, lateral septum, obesity, stress / Includes bibliographical references. / Diana Williams, Professor Directing Dissertation; Lynn Panton, University Representative; Alan Spector, Committee Member; Debra Fadool, Committee Member; Chris Schatschneider, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_709839 |
| Contributors | Terrill, Sarah J. (Sarah Joyce) (author), Williams, Diana L. (Professor Directing Dissertation), Panton, Lynn B. (Lynn Bishop) (University Representative), Spector, Alan C. (Committee Member), Fadool, Debra Ann (Committee Member), Schatschneider, Christopher (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 (117 pages), computer, application/pdf |
Page generated in 0.0018 seconds