Behavioral Effects of L. plantarum in Drosophila and the Role of Intestinal Alpha-4 ACh Receptors
Discipline: Biological Sciences
Subcategory: Microbiology/Immunology/Virology
Session: 2
Room: 1 - Hanover DE
Geraldine M. Ortiz Sosa - University of Puerto Rico, Rio Piedras
Co-Author(s): Melanie Reinoso Arnaldi, University of Puerto Rico, Rio Piedras; Dr. Imilce A. Rodriguez Fernandez, University of Puerto Rico, Rio Piedras
The gut-microbiota-brain axis is a complex communication network that connects the brain, the gut, and its resident microbiota. While this axis is vital for maintaining gastrointestinal homeostasis, it influences behavior and mental activity. Besides the nervous system, neurotransmitters can also be produced by the intestinal epithelium and gut bacteria. Of interest is Lactiplantibacillus plantarum (L. plantarum), a probiotic and commensal bacteria that produces acetylcholine (ACh). Studies in Drosophila have shown that ACh receptors are expressed by gut enterocyte cells and ACh can arise from gut enteroendocrine cells and anti-inflammatory recovery-specific cholinergic enteric neurons. This project focuses on exploring the role of ACh signaling in the Drosophila gut and assesses whether L. plantarum could serve as a significant source of ACh, as well as test its potential to modify different behaviors. To do this, we generated transgenic flies in which we knocked down nicotinic acetylcholine receptor alpha 4 (nAChRa4) or control using RNAi in the gut for 11 days during adulthood. Then we administered L. plantarum (strain LpWF) or mock treatment and measured the climbing ability of treated control and transgenic flies 1, 3, 24, and 120 hours after treatment. Our data suggests that motor function in young Drosophila adults is altered by the administration of L. plantarum strain WF at 3 hours, with recovery observed after 24 hours. However, this effect is not observed when nAChRa4 is knocked down which suggests that this LpWF-mediated effect may require AChRɑ4 expression in the gut. We also developed a new protocol to detect neurotransmitters produced by bacteria biofilms growing on glass slides. Our preliminary immunostaining results suggest ACh could be detected in all bacteria biofilms tested: L. plantarum (two stains LpWF and Lp39) and E. coli. These results suggest that the changes in behaviors observed with L. plantarum administration may require intestinal ACh signaling and that L. plantarum could produce ACh. We will further characterize the effect of LpWF on other behaviors, such as social triangles and DAM2 Trikinetics Monitors, to determine whether gut-specific ACh signaling is required. Immunohistochemistry will be also performed on fly guts to assess potential ACh production by L. plantarum. We aim to characterize the molecular mechanism by which LpWF modifies climbing behavior and the role of acetylcholine signaling in this process.
Funder Acknowledgement(s): We thank the funding provided by the NSF Grant #2216584, UPRRP Start-Up funds, NIH-NIGMS COBRE (5P20GM103642), and the Catalyzer Research Grant (#2023-00056) Puerto Rico Science, Technology & Research Trust (PRST). Special thanks to Dr. Imilce Rodriguez Fernandez (PI), Dr. Andrew Seeds (Co-Mentor), and the IRF Lab.
Faculty Advisor: Dr. Imilce A. Rodriguez Fernandez, imilce.rodriguez1@upr.edu
Role: The research project outlined in the abstract is an independent research project that I am working on as a Post-Baccalaureate student. I generated the transgenic fly model through crosses of two different fly strains, administered the probiotic L. plantarum to the flies and conducted the behavioral climbing assays. Additionally, I developed the protocol for bacterial immunostainings and performed it for E. coli and L. plantarum (LpWF and Lp39 strains) biofilms. Thus, most of the experiments assigned have been carried out independently.