Hindbrain glucagon-like peptide 1 (GLP-1) neurons project to numerous feeding-relevant forebrain areas. One such region is the lateral septum (LS), which plays a role in learning,
motivation, and stress. We hypothesized that stimulation of GLP-1R in the LS affects food intake. Rats were implanted with unilateral cannulas targeting the LS, and intra-LS injections were
made 30 min before dark cycle onset. We examined the effects of the GLP-1R agonist Exendin 4 (Ex4) at doses subthreshold for effect when delivered to the lateral ventricle (0.01 or 0.025 µg).
Ex4 had no effect on feeding at 2 and 4 h into the dark phase, but the 0.025 µg dose suppressed overnight intake. We then assessed the effects of ventricle-subthreshold doses (1.0, 2.5, 5.0,
or 10.0 µg) of the GLP-1R antagonist Exendin (9-39) (Ex9) vs vehicle injected into the LS. Ex9 increased chow intake at 2, 4, and 20 hours post-dark onset relative to vehicle. We assessed the
role of LS GLP-1R in motivation for food by examining operant responding for sucrose on progressive ratio (PR) schedule. Intra-LS injections of Ex9 (10.0 µg) or vehicle were made 45 min prior
to the start of the PR session. We also tested PR responding after a nutrient preload designed to maximize GLP-1 neuron activation. The preload strongly suppressed PR responding, but blockade
of LS GLP-1R did not affect motivation for sucrose in either preload condition. The Ensure preload significantly suppressed 24-hour chow intake relative to no preload condition. However,
intra-LS Ex9 treatment significantly reduced this compensatory reduction in chow intake after the preload. These experiments suggest that the LS is a relevant site for neuronal GLP-1
influence on food intake. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester, 2014. / October 1, 2014. / Food Intake, GLP-1, Lateral Septum / Includes bibliographical references. / Diana Williams, Professor Directing Thesis; Alan Spector, Committee Member; Colleen Kelley, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_253415 |
| Contributors | Terrill, Sarah J. (authoraut), Williams, Diana L. (professor directing thesis), Spector, Alan C. (committee member), Kelley, Colleen M. (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Psychology (degree granting department) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource (33 pages), computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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