Poster 36 - Calcium in the Cortex: Decoding Neuronal Signals in Alzheimer’s Disease vs. Wild Type Cells

Saturday, October 26, 2024

10:00 AM - 12:00 PM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Nicole Ching

Volunteer Research Intern
Institute of Engineering in Medicine, United States

Co-Author(s)

HH

Huiying Huang, n/a

Undergraduate student
University of California, San Diego, United States

Co-Author(s)

Srirohan Pokuru (he/him/his)

Volunteer Research Intern
Institute of Engineering in Medicine, California, United States

Co-Author(s)

Krishna Vijay

Volunteer Research Intern
Institute of Engineering in Medicine
Camas, Washington, United States

Co-Author(s)

MA

Max Arola (he/him/his)

Volunteer Research Intern
Institute of Engineering in Medicine
San Diego, California, United States

Co-Author(s)

Maya K. Krishnan (she/her/hers)

Volunteer Research Intern
Institute of Engineering in Medicine
San Diego , California, United States
YM

Yolotzin M. Mendez (she/her/hers)

Volunteer Research Intern
Institute of Engineering in Medicine
Mojave, California, United States
CL

Connor Lee

Volunteer Research Intern
Institute of Engineering in Medicine, United States
Crystal Cheng (she/her/hers)

Student
Torrey Pines High School, California, United States
CW

Chengbiao Wu

Professor
UCSD School of Medicine Dept of Neuroscience, Outreach Program for Advancing Learning in STEM (OPALS), United States

Last Author(s)

Veronica Gomez-Godinez, PhD (she/her/hers)

Project Scientist
Institute of Engineering in Medicine, UCSD, United States

Primary Investigator(s)

Linda Shi, PhD (she/her/hers)

OPALS Program Director, Project Scientist, Co-director IEM
University of California, San Diego: Institute of Engineering in Medicine
La Jolla, California, United States

Introduction: Alzheimer’s Disease (AD) is a neurodegenerative disease that causes irreversible memory loss. It targets the hippocampus and entorhinal cortex of the brain causing synapse destruction, amyloid plaque, and cell death. Calcium (Ca2+) plays a central role in the proliferation, motility, and specialization of cells; it has been shown to have an increased presence at sites of injury, aiding in the recovery process. In this research, we simulated a traumatic brain injury (TBI) by using Laser-Induced Shockwave (LIS) and observed the immediate molecular events and Ca2+ response by using the fluorescent Ca2+ indicator Fluo-4 AM, a green dye to help visualize responses. Our objective was to contrast neurodegenerative diseased cells’ Ca2+ dynamics with wild-type (WT) cells in order to further understand how the brain responds to acute damage when it is diseased compared to healthy. Cells were treated with SARM-1 inhibitors to determine whether drug treatment had any effects on the calcium response. Both AD and WT cells were treated with DMSO, which is a protectant for the cells against harmful chemicals.

Materials and

Methods: Cortical neurons from mice with and without AD were cultured with cell medium under 37 degrees Celsius. Cells were loaded with Fluo-4 AM and LIS to study calcium levels. LIS uses a laser we fire at a group of brain cells, which then creates a cavitation bubble that expands and rapidly collapses causing subsequent death to cells in the bubble's vicinity. A 1032 nm laser was focused 10 µm above the substrate which contained the neurons. Imaged at various distances from the focus point, Six hundred frames of the cells were captured from this camera, both pre- and post-shockwave. FIJI/ImageJ was the application in which these images were uploaded, so we could circle 10 to 20 dead cells and all live cells that did not shift significantly after shockwave. These identified cells were then transferred manually to a MatLab application which could access a program analyzing the calcium levels of the regions of interest. We then collected important pieces of data such as raw intensities, distance, and peak location for data analysis and graph generation. [1]

Results, Conclusions, and Discussions: Results and

Discussion: For our graphs, we measured neuronal calcium changes in mean pixel intensity through peak values of different treated cells. Peak values, indicative of immediate calcium changes were extracted and combined for certain fields of view. We found no statistical differences between WT and AD cells or AD DMSO vs AD SARM1 inhibited cells. However, we found that WT SARM1-inhibited cells may have a lower calcium response than WT DMSO. Greater N-values of WT SARM1 inhibited cells are necessary to solidify our conclusions. Additionally, we did not observe differences in initial calcium levels between cell groups with current data.

Conclusion: Based on our results, we concluded that there is a statistical difference between the intracellular calcium peak value of WT SARM1-treated and WT DMSO-treated neurons. This means that WT SARM1 cells had lower peak values than WT with DMSO, suggesting that WT SARM1-inhibited neurons did not have as large of a calcium response as WT DMSO-treated ones. There were also no observed differences between AD and WT cells or the differently treated AD cells, DMSO and SARM1. In the future, we hope our research can inspire researchers to pursue the path to a cure for this disease.

Acknowledgements (Optional): This material was based upon work supported by a gift from Beckman Laser Institute Inc. to V. G. G. & LS. . The high school students (*) participated in UCSD OPALS internship. Special thanks to Dr. Shu Chien from UCSD Bioengineering and Dr. Lizhu Chen from CorDx Inc. for their donations.

References (Optional): [1] Godinez, V. G., Morar, V., Carmona, C., Gu, Y., Sung, K., Shi, L. Z., Wu, C., Preece, D., & Berns, M. W. (2021). Laser-Induced Shockwave (LIS) to study neuronal CA2+ responses. Frontiers in Bioengineering and Biotechnology, 9. https://doi.org/10.3389/fbioe.2021.59889