University Honors

Optogenetics is a powerful piece of technology that is highly utilized in neuroscienceresearch. It makes use of light and channelrhodopsin proteins to remotely manipulateneuronal circuits and behavior of organisms in vivo. Ecdysis Triggering Hormone (ETH) is apeptide hormone that is produced by endocrine Inka cells in arthropods. Previous workshowed that ETH injection inhibits courtship behavior in male Drosophila melanogaster,indicating a reproductive role in adult Drosophia melanogaster. The goal of this study is touse optogenetic manipulation to test the hypothesis that elevation of endogenouslyreleased ETH likewise inhibits courtship behavior. That is done using red light exposure ata wavelength of ~600nm and a dose dependent duration. That allows cuticle penetration,which should elevate endogenous ETH levels using light-gated CS-Chrimson channels. Redlight entry into the cell causes the channel to open and an influx of Na+ and Ca+,depolarizing the Inka cell and activating vesicular exocytosis of ETH. This exposure will bedone on progeny of GAL-4 ETH x UAS CS-CHRIMSON and we will focus on the malebehavior in this study. We will have two controls that consist of a female Canton S and maleGAL-4 or UAS respectively. Results will be measured by placing the male cross line x femaleCanton S. They will be allowed to court for 10 minutes and video recorded. These videoswill then be scored by recording expressed courtship behavior and calculating thecourtship index (CPI). While previous studies in the Adams lab show inhibition of courtshipbehavior by the injection of ETH, this approach is less invasive and allows physiologicallevels of ETH. but is expected to provide similar results. This knowledge of optogenetics isimportant to understand organisms’ behavior in a less invasive methodology to geneticmanipulation of behavior and its further uses in neuroscience research.2ACKNOWLEDGMENTSI would like to thank my faculty mentor and primary investigator, Dr. Michael Adams, for hiscontinued support throughout this project, in the lab, as well as in my academic career overthe past 3 years. I would also like to thank my lab peers Ramtin Ghafoori and CameronZappetta for explaining many concepts to me and keeping me motivated. Finally, I wouldlike to thank my partner throughout this project, Aiden Bryan, for dedicating countlesshours with me in the lab for the success of this project, even when I was unable to.