Israel Smith Flores
Pronouns: He/Him
Research Mentor(s): Joseph Letner
Co-Presenter:
Research Mentor School/College/Department: Biomedical Engineering / Engineering
Presentation Date: April 20
Presentation Type: Poster
Session: Session 2 – 11am – 11:50am
Room: League Ballroom
Authors: Israel Smith Flores, Joseph Letner, Cynthia Chestek
Presenter: 74
Abstract
Neural electrodes are integral tools for brain-machine interfaces, which can restore function for tetraplegic individuals (Collinger et al., 2013). Despite the rapid increase in the use of implanted electrodes clinically and in research, there does not exist a standardized method of testing novel electrodes (Thompson et al., 2020). The development and assessment of new electrodes are needed because current silicon electrodes induce extremely negative tissue responses which can be harmful to the human brain (Szymanski et al., 2021). Carbon fiber electrodes have been shown to be promising next-generation electrodes because of their minimal negative foreign body response (Patel et al., 2016; Welle et al. 2020) This study focuses on a closeup histological assessment of carbon fiber neural probes chronically implanted in rats. One electrode was implanted in the right hemisphere of the brain in layer V of the motor cortex of each rat. The electrical activity of the motor neurons of the rats was recorded for 88 days in one rat and 91 days in the other. After the recording was finished, the rat brains were then stained with immunohistochemistry and imaged using a confocal microscope. The images were prepared using ImageJ. We used the ImageJ nTracer (Roossien et al., 2019) plugin to identify neurons around the implanted fibers and contralateral to the fibers. Preliminary histological analysis of the neurons shows some negative tissue response may be present, such as neuron stretching. However, the negative response overall is much less severe than the response that is caused by silicon electrodes, as we have seen in Patel et al. (2016). While current analysis shows that the carbon fiber electrodes elicit a less negative response than the silicon electrodes, more data processing needs to be performed.
Engineering
