By John O'Toole, Neurobiology & Spanish; Carly Kelley, University of Cincinnati; Noe Alvarez, University of Cincinnati
Advisor: Elke Buschbeck
Abstract: The implantation of electrodes to measure changes in voltage has been used clinically and in research to further develop knowledge of neural activity. These electrodes typically consist of rigid, metallic fibers. Over time, it has been shown that such electrodes tend to become less efficient, possibly due to micro-lesions and scar-tissue formation in response to rigid materials interacting with the soft and moveable tissue of the nervous system. In this project we evaluate the use of carbon nanotube (CNT) electrodes, as a soft, and chemically inert material and test how efficient such electrodes are for long-term neural recordings. Specifically, we monitor neural responses from-long term implanted electrodes in insects using electroretinography (ERGs). In addition to neural recordings we use histological examination of the tissue-fiber interface of long-lived Madagascar Hissing Cockroaches, several month after implantations. Using inert and noninert metallic controls, silver and gold respectively, our preliminary findings suggest that carbon nanotube wires integrate particularly well with surrounding tissue. Our project focuses on testing fibers that have been further modified by functionalization with molecules that naturally occur in the nervous system, such as the neurotransmitter glutamate. Such treatments will enhance material properties including their hydrophobicity, and our studies on insects represent an important screening tool for further improvements of electrodes that maintain proper electron transfer with enhanced bio-cooperability.