04/01/2021
By Susan Pryputniewicz

The Biomedical Engineering and Biotechnology program invites you to attend a doctoral dissertation defense by Mary Guaraldi on “Development and Refinement of a Novel Interface and Software Program ("Raptor") that Provides Bi-directional Interaction of Computers and Neuronal Networks."

Ph.D. Candidate: Mary Guaraldi
Date: Thursday, April 15, 2021
Time: 3 – 5 p.m.
Location: This will be a virtual defense via Zoom. Those interested in attending should contact the candidate and committee advisor at least 24 hours prior to the defense to request access to the meeting.

Committee Chair (Advisor): Thomas B. Shea, Ph.D., Department of Biological Sciences, University of Massachusetts Lowell

Committee Members:

  • Frederic Chain, Ph.D., Assistant Professor, Department of Biological Sciences, University of Massachusetts Lowell
  • Peter Gaines, Ph.D., Professor, Department of Biological Sciences, University of Massachusetts Lowell
  • Jeffery Moore, Ph.D., Professor, Professor, Department of Biological Sciences, University of Massachusetts Lowell

Abstract:
Diets high in saturated fat and cholesterol have been implicated in contributing to cognitive decline and neuronal degeneration observed with aging and with diseases such as Alzheimer’s Disease. These diets are associated with free radical formation leading to oxidative stress, metabolic inflammation, insulin resistance, impaired integrity of blood brain barrier, elevation of cerebral amyloid deposition, and tau hyperphoshorylation. All of these factors may contribute to the progression of neuronal damage. Animal models, including transgenic mice, have been employed to evaluate the effect of diet on neuronal health and function.

In order to assess the effects of a diet high in fat and cholesterol, wild-type and transgenic mice were exposed to normal and high fat/high cholesterol diets and markers of oxidation were measured in brain homogenates. Neuronal function was assessed via behavioral studies following chronic high fat/cholesterol exposure. These studies demonstrated that the diet increased oxidative species over time, but functional decline was not seen.

To evaluate neuronal function at the cellular level, multi-electrode arrays (MEAs) were employed to measure changes in the electrical activity of dissociated cells and hippocampal slices and assess the effects of nutrition and environmental oxidizers on them.

Commercial MEA systems are available but require a level of financial investment that is prohibitive for laboratories that require extramural support, since preliminary data justifying such support cannot be obtained in the absence of a computer-neural network interface. In efforts to address this need, the MEA recording system described herein was compiled using components that were commercially available and assembled using a custom interface. The program (“Raptor”) designed to operate the system was written specifically for ease of use and is adaptable to several types of studies. Herein, we demonstrate that this custom system is capable of recording of spontaneous signals of neuronal networks, analysis and manipulation of network development, monitoring of the influence of environmental toxins on network activity, and finally, embodiment of ex vivo neuronal networks via video-based sensory input and prosthetic motor output.

The Raptor system was used to record signals in a variety of research areas including:

  • Neuronal network development
  • Neuronal network signaling in models of disease
  • Neuronal network control of robotics

This system has been a powerful tool to study neuronal networks and has provided several students with data that has been published in peer- reviewed journals. Proposed studies are included that will demonstrate the usefulness of the Raptor system and may provide insight on the effects of nutrition on neuronal degeneration and models of disease. The Raptor system also has functionality built-in which allows it to be an interface between cells and robotic hardware.

All interested students and faculty members are invited to attend the online defense via remote access.