Processing of Magnetic Resonance Electrical Impedance Tomography data for the Direct Detection of Neural Activity in an Aplysia Model

Student:
Maame Abena Oforiwaa Afrifa

Project Mentors:
Dr. Rosalind Sadleir – SBHSE
Dr. Stephen Helms Tillery – SBHSE
Dr. James Abbas - SBHSE

YouTube Link:
View the video link below before joining the zoom meeting

Zoom link:
https://asu.zoom.us/j/92050894126

Zoom meeting time:
9am - 11am

Abstract

A sequence of experiments was performed in vitro to verify the existence of a new magnetic resonance imaging contrast using Magnetic Resonance Electrical Impedance Tomography (MREIT). MREIT is sensitive to changes in active membrane conductivity and can be used to perform functional studies. Functional MREIT may have promise as a more direct method of functional neuroimaging than existing methods that image correlates of blood flow such as BOLD fMRI.

In a previous study, standard deviations in MREIT phase data of spontaneously active Aplysia abdominal ganglia in an artificial seawater (ASW) background solution were compared before and after treatment with an excitotoxic solution (KCl). There was a significant increase in MREIT treatment cases, compared to control ganglia subject to extra ASW. This distinction was not found in phase images from the same ganglia using no imaging current or in analysis of standard deviations in image backgrounds. The conclusion was that our observations were linked to changes in cell conductivity caused by activity.

If activity increased after KCl treatment, it is expected that the Laplacian of phase data within Aplysia tissue should decrease. In this study, Laplacian data acquired from the earlier experiment was reanalyzed using MATLAB to determine if this change was distinguishable.