Introduction In 1998, the Calorie Control Council estimated that 144 million American adults regularly consume low-calorie, sugar-free products. To date the U.S. Food and Drug Administration have approved five sugar substitutes, one of them being aspartame. Purpose The purpose of this study, is to determine the effects of aspartame consumption on fat deposition in C. elegans as a potential indication of aspartame activation of the cephalic response. Hypotheses Hypothesis #1: The starved (lean) C. elegans will demonstrate no difference in fat deposition between groups. Hypothesis #2: Supplementation of aspartame will lead to an increase in fat deposition due to a cephalic response. Cephalic Phase Response Giduck (1987) found that oropharyngeal - stimulated responses are reliably initiated by the taste and smell of food. Nicolaidis (2003) suggests that cephalic responses play an important role in the regulation of both digestive and metabolic processes and act to optimize the utilization of the ingested nutrients. Salivary Secretions The sight, smell, thought or taste of food initiates the cephalic response through salivating. Blood sugar levels decrease. The sight, smell, thought or taste of food initiates the cephalic response through salivating. Blood sugar levels decrease. Gastric Secretions Dive – like mechanism is stimulated in the brain which creates a greater desire for food. Originates from the cerebral cortex and appetite centers of the brain which are mediated by the vagus nerve. Dive – like mechanism is stimulated in the brain which creates a greater desire for food. Originates from the cerebral cortex and appetite centers of the brain which are mediated by the vagus nerve. Literature Review Ashrafi (2007) and Rankin (2005) found that due to the chemo sensitivity and cephalic response system in C. elegans, they are an ideal organism for the study of energy balance (fat deposition).

Methodology Sudan Black Staining & Nomarski Optics Used for the identification of fat deposits in C.elegans intestines Glucose Supplemented N2 Aspartame Supplemented N2 Control Starved N2 N2 Strain Caenorhabditis elegans (n=30) Pilot Studies Conducted prior to experimentation in order to determine the needed concentrations of glucose and aspartame for the axenic liquid medium (10%). Statistical Analysis - ANOVA (Sheffe Post Hoc) (p<.05) Mean + SD Fat Deposition Measurements (Photoshop) Relative Luminosity Evaluation This bar graph demonstrates the dark pixel mean (from the Adobe Photoshop Histogram Function) of the control group ( ), glucose supplemented group ( ) and the aspartame supplemented group ( ). Images of the stained C. elegans were evaluated for relative luminosity. Regions of black pixels in the image (representing areas of fat deposition) were compared to the lighter areas of negligible fat deposition. The dark pixel mean of the image was reported and used for statistical analysis of the overall fat deposition.

Control Starved C. elegans (Mean = dark pixels) Glucose Supplemented C. elegans (Mean = dark pixels) Aspartame Supplemented C. Elegans (Mean = dark pixels) Discussion I An early limitation of the study included a non- sterile laboratory environment. Contamination of C. elegans cultures created a food source from which the worms would feed, essentially prolonging their lifespan. Additionally, there was an inability to precisely record the absorption of the glucose and the aspartame by the C. elegans. Discussion II The mean fat deposition of each group reflects the starved worms compensating for negligible calories by storing more fat. The glucose supplemented worms deposited fat by consuming excess calories from the glucose. The aspartame supplemented worms deposited the least amount of fat since aspartame is not a source of energy which the C. elegans could feed off of. The one-way ANOVA followed by a Sheffe Post Hoc (p<.05) revealed a significant difference between the control and glucose supplemented groups and the glucose and aspartame supplemented groups. No significant differences were found between the control and glucose supplemented groups. Conclusion This study rejects hypothesis #1 due to differences in fat deposition found between the C. elegans groups as previously mentioned. This study also rejects hypothesis #2 since supplementation of aspartame does not lead to increased fat deposition. It is believed that this may be due to a lack of available energy sources in the aspartame group. Future Studies Possible future studies could include…  Incorporating the no-calorie sweetener Sucralose (Splenda) into future trials and observing subsequent fat deposition.  Training C. elegans in an aspartame feeding environment and transferring them into a glucose feeding environment to measure fat deposition. Bibliography Abegaz, Eyassu G. "Aspartame Not Linked to Cancer." The Free Library Aginomoto Corporate.. "Artificial Sweeteners: No Calories... Sweet!" FDA Consumer Magazine July-Aug "Artificial Sweetener." The Columbia Encyclopedia Columbia UP.. Ashrafi, Kaveh. "Obesity and the Regulation of Fat Metabolism." Worm Book - the Online Review of C. elegans Biology. 9 Mar Aspartame Information Center Calorie Control Council.. Blundell, JE. "Paradoxical Effects of an Intense Sweetener (Aspartame) on Appetite." Pub Med 1 (1986): Denoon, Daniel J. "Study Links Aspartame to Cancer." CBS News WebMD.. Fushiki, Tohru. "Chemical Reception of Fats in the Oral Cavity and the Mechanism of Addiction to Dietary Fat." Chemical Senses 30 (2005): Giduck, Sharon A. "Cephalic Reflexes: Their Role in Digestion and Their Possible Roles in Absorption and Metabolism." Journal of Nutrition 117 (1987): Gold, Mark D. "The Bitter Truth About Artificial Sweeteners." Nexus Magazine Gorman, Christine. "A Web of Deceit." Time Magazine 8 Feb Lavin, JH. "The Effect of Sucrose- and Aspartame- Flavored Drinks on Energy Intake, Hunger, and Food Choice of Female, Moderately Restrained Eaters." International Journal of Obesity 17 (1997): Li, Yang. "Mapping Determinants of Gene Expression Plasticity by Genetical Genomics in C. Elegans." PLOS Genetics (2006). Nicolaidis, S. "Early Systemic Responses to Orogastric Stimulation in the Regulation of Food and Water Balance: Functional and Electrophysiological Data." The New York Academy of Sciences 157 (1969): Sarles, H. "Cephalic Phase of Pancreatic Secretion in Man." Gut 9 (1968): Selim, Jocelyn. "The Chemistry of Artificial Sweeteners." Discovery Magazine 6 Aug