Neuropeptide Y-Mediated Control of Appetitive and Consummatory Ingestive Behaviors in Siberian Hamsters (Phodopus sungorus)

During the past few decades, obesity has risen significantly in the United States with recent estimates showing that 65% of Americans are overweight and 30% are obese. This increase is a major cause for concern because obesity is linked to many secondary health consequences that include type II diabetes, heart disease, and cancer. Current approaches to the obesity problem primarily have focused on controls of food intake and have been largely unsuccessful. Food, however, almost always has to be acquired (foraging) and frequently is stored for later consumption (hoarding). Therefore, a more comprehensive approach that includes studying the underlying mechanisms in human foraging and food hoarding behaviors could provide an additional target for pharmaceutical or behavioral manipulations in the treatment and possibly prevention of obesity. Neuropeptide Y (NPY) is a particular peptide that provides a potent orexigenic drive to alter foraging, food hoarding (appetitive ingestive behaviors) and food intake (consummatory ingestive behaviors) in variety of species. NPY is predominantly produced in the arcuate nucleus of the hypothalamus (ARC) and has extensive efferent projections throughout the brain. Two target nuclei of ARC-NPY, the paraventricular nucleus of the hypothalamus (PVH) and perifornical area (PFA), have been shown to mediate the effect of NPY on food intake in laboratory rats and mice, but nothing is known about the effect of ARC-NPY on foraging and food hoarding. In addition, the action of specific NPY receptor subtypes within these two nuclei for these behaviors is unknown. Even though ARC-NPY is one of the main sources of input into the PVH and PFA, it is not known if this NPY fiber projection mediates alterations in appetitive and consummatory ingestive behaviors. Therefore, the purpose of this dissertation is to test 1) if NPY within the PVH or PFA controls appetitive, as well as, consummatory ingestive behaviors, 2) if NPY Y1 receptors within the PVH or PFA differentially control appetitive or consummatory ingestive behaviors, and 3) if NPY from the ARC is necessary for the control of appetitive and consummatory ingestive behaviors

Neuroanatomical Tracing of the Gut -- Brain Axis

This poster summarizes a variety of methods to further characterize the gut-brain axis by tracing motor and sensory nerves between the gut and brain and identifying cell bodies in the sensory ganglia. Determines the meth method to trace the sensory and motor nerves was through fluorescence and the best method to identify sensory neuron cell bodies was the Nissi stain

Sex differences on the effect of obesity on the morphology of the intestinal epithelium

It is known that obesity causes the morphology of lining of the small intestine, the epithelium, to change. It causes the villi, the finger like projections responsible for nutrient absorption, to be longer. It also causes the crypts, which contain the stem cells, to be deeper. The differences of morphology between male and female mice have not been previously studied. This project involves inducing obesity in mice using a high fat diet and then observing the effect on the length of the villi and crypts of in the small intestine. Results from this study can contribute to the understanding of the mechanisms of nutrient triggered cellular adaption of the intestine and can also provide insight to intestinal diseases.Ope

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Alpha2A Adrenoreceptor Influence on Intestinal Epithelial Stem Cell Proliferation

The intestinal epithelium is critical for nutrient absorption, immune function, and hormone release. The mature cell types that are responsible for these functions are produced by crypt base columnar (CBC) stem cells located within the intestinal crypts. These stem cells constitutively divide to produce complete turnover of the entire intestinal epithelial layer every few days. The division of the CBCstem cells can be influenced by a variety of factors, including nutrient availability. There is research that suggests the sympathetic nervous system can contribute to changes in stem cell proliferation. However, it is not known whether this effect is direct via the CBC stem cells, or instead through an indirect mechanism. Thus, we tested whether CBC stem cells express alpha2Aadrenoreceptors (α2A-ARs), a receptor subtype utilized by norepinephrine (NE; the primary neurotransmitter of the SNS) and whether NE induces proliferation of intestinal epithelial organoids in vitro. Results showed that α2A-ARs mRNA is expressed in CBC stem cells and that there is a trend towards higher expression of α2A-AR mRNA in CBC stem cells compared with other cells of the crypt. We also found a significant decrease in proliferation after application of NE to organoids in vitro(p<.05). These data support a role for the SNS in regulation of CBC stem cells proliferation, which may influence intestinal epithelial size and function as a whole.Ope