Developing an ACURE to Investigate the Effects of Manganese on Physiological Processes

Abstract

To engage freshman college students in research and STEM, we will utilize an authentic course-based undergraduate research experience (ACURE) approach through a focused research project. Introducing students to novel research projects within a course setting provides a structured way to expose participants to the process of scientific research. Involvement in the design and implementation of an experiential paradigm promotes creativity among students and encourages them to become more engaged. Through the process of gathering and analyzing data, students will gain a realistic perspective of scientific research. For this class project, we chose to focus on studying the effects of manganese on behavior, neural function and cardiovascular physiology of Drosophila melanogaster larvae and crayfish models. Emerging research has repeatedly demonstrated that overexposure to manganese in humans can lead to acute cardiovascular disorders and a series of symptoms manifesting in a manner similar to that of Parkinson's disease (PD). We have designed the class in order to gain a multifaceted understanding of these effects. To do so, the students will first examine larval crawling rate, mouth hook movement rate, and touch sensitivity of control larvae and larvae exposed to a maximum non-lethal dose of manganese in order to analyze the effect that manganese has on the behavior of D. melanogaster. Then, students will use optogenetics to activate and inactivate dopaminergic neurons in order to compare behavioral responses of the control group to the group exposed to manganese. In doing so, they will be able to gain understanding of another method of scientific investigation and further build upon the variety of data found throughout the study. Manganese also has the potential to block voltage-gated calcium channels of the heart, so the students will additionally study the effect of manganese exposure on D. melanogaster heart rate and rhythmicity in order to demonstrate the effect that manganese can have on other areas of the body. Finally, students will study the synaptic transmission at glutamatergic neuromuscular junctions by observing and recording data from the muscle fibers of both larval D. melanogaster and crayfish. Like the heart, these neuromuscular junctions contain voltage-gated calcium channels, so the students will be able to further explore the various effects of manganese exposure. The utilization of crayfish in this study will allow the students to gain a new perspective of the effect of manganese because of the ability to record crayfish action potentials intracellularly, something that is not possible to study in D. melanogaster. Overall, we believe that this student-driven research approach will promote student engagement and foster a deeper understanding of the scientific process while also widening the breadth of knowledge in the research field.