Hooked on Sweetness: Testing Light Attraction in Planaria with Alternative Sweeteners

Artificial sweeteners are a common additive to the human diet, with products like Splenda and Equal marketed as healthier alternatives to traditional sugars. These sweeteners that have been examined for their rewarding and withdrawal effects in planarian flatworms. Planaria are photophobic organisms that typically swim away from light. Previous research suggests that planaria can learn through conditioning when exposed to Splenda, Equal, and sucrose in both light and dark environments. This experiment differs as it seeks to test whether planaria can be conditioned to swim toward the light when exposed to alternative sweeteners such as Stevia and a Stevia-Splenda blend. It also tests whether these sweeteners have similar rewarding effects and how the chemical contents compare to those in the earlier studies. During the conditioning period, planaria were exposed to a sweetener in the light for a period of time, followed by a transfer to unsweetened water in the dark for the same time. If the conditioning is successful, the planaria would go against their typical behavior and swim toward the light when given the choice of either dark or light. They would successfully be taught through conditioning to associate the light environment with a rewarding sweetener. The results of this experiment suggest that after conditioning, there was no significant effect on the time spent in the light. Future research questions focus on the neurological effects of sucrose on planaria when used for conditioning.