Aiden Crowley
Pronouns:
Research Mentor(s): Martin Myers Jr
Research Mentor School/College/Department: / Medicine
Program:
Authors: Aiden Crowley, Allison Duensing, Martin Myers, M.D., Ph.D
Session: Session 6: 3:40 pm – 4:30 pm
Poster: 28
Abstract
As cases of obesity and diabetes continue to rise worldwide, there is a heightened need for understanding these conditions to better inform therapeutic intervention. One signaling molecule implicated in obesity is leptin. Leptin is a hormone released by adipose tissue in proportion to fat levels in the body and is therefore indicative of stored energy in the system. Neurons in the brain that are responsive to leptin express the leptin receptor (gene-Lepr, protein-LepRb), and control hunger and systemic energy balance in response to leptin. LepRb neuronal dysfunction along with other lifestyle factors, such as mistimed eating, can lead to metabolic diseases in humans. Using transgenic mice, the Myers laboratory identified a population of LepRb neurons located in the dorsomedial hypothalamus (DMH) which also expresses the glucagon-like peptide-1 receptor (Glp1r) (LepRbGlp1r neurons). These neurons function to suppress body weight and inhibit food-seeking neurons; however, little is known about what activates LepRbGlp1rneurons to cause these responses. Other studies suggest that DMH LepRb neurons are crucial in the maintenance of diurnal mealtime and thermoregulation. Here, we will test the hypothesis that LepRbGlp1r neurons will have higher activation during resting hours. In this study, we will use Lepr-cre;Glp1r-flp; RCFL-GFP (n=8) transgenic mice and immunohistology to identify what time of day the neurons are active. To determine when the LepRbGlp1r neurons are active, brain tissue is collected every six hours, beginning at the onset of the light cycle. In our mouse model, the LepRbGlp1r neurons express GFP molecules, allowing us to use antibody staining for both GFP protein and FOS, a protein present in active cells. Our results show that LepRbGlp1r neurons activity is not robustly different over the 24-hour light/dark cycle, indicated by a lack of overlap between FOS and GFP.
