Investigation of the Synergistic Nature of Traumatic Brain Injury and Opioid Exposure on Generation of Reactive Oxygen Species

Alexander R. Woznicki, Rachel E. Godfrey, Scott C. Lloyd, Dr. Kelly E. Bosse, and Dr. Alana C. Conti John D. Dingell VA Medical Center and Dept. of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI

Although opioids are commonly used for post-injury pain management, their effects on traumatic brain injury (TBI)-induced pathology remain unclear. TBI or morphine alone can generate reactive oxygen species (ROS), which can result in oxidative stress and inflammation. Therefore, we hypothesize that morphine exposure post-TBI may exacerbate ROS induction. This work aimed to localize and compare the extent of ROS generation across brain regions after exposure to TBI and/or morphine by quantifying dichlorofluorescein (DCF), which fluoresces upon contact with ROS.

Male mice (10-12 weeks old, n = 3-4/group) were exposed to moderate, closed-skull TBI or sham (control) surgery. Starting 24 hours after injury, mice received repeated morphine or saline (control) injections in an escalating dose pattern. Frozen coronal brain slices (12 um) were slide-mounted, incubated in 20 uM DCF, washed in PBS, and coverslipped with fluorescent mounting medium. After 96 hours, tissue sections were imaged using fluorescence microscopy and analyzed using ImageJ software.

Preliminary results show an effect of combined morphine and TBI on ROS levels compared to those in control tissues throughout the cortex, hippocampus, and nucleus accumbens. A similar profile of regional changes have been observed in tissue processed with in vitro ROS/Reactive Nitrogen Species (RNS) biochemical assays that are the present gold standard. The data collected by the ROS/RNS assay further validate this novel technique of DCF staining in whole brain slices for enhanced spatial resolution.

Our data suggest that post-TBI opioid exposure may exacerbate TBI pathology, supporting a role for development of non-opioid based therapies useful for post-injury pain management. 

Funding Source: This work was supported with resources and the use of facilities at the John D. Dingell VA Medical Center, Detroit, MI, SPIRE Award RX003198 (KEB), VA Merit Award RX003267 (ACC), and the Richard Barber Interdisciplinary Research Program (ACC, ARW, REG). 

Additional Abstract Information

Presenter: Alexander Woznicki

Institution: Wayne State University

Type: Poster

Subject: Biology

Status: Approved

Time and Location

Session: Poster 2
Date/Time: Mon 3:00pm-4:00pm
Session Number: 2571