Simultaneous Electrophysiology and Optical Recording of Neuronal Activity

• Main Author: McCullough, Connor M
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2022
• Subjects: Neurosciences; Optics
• ISBN: 9798358493926

Methods for measuring neuronal activity are the most essential tool for neuroscience research. Understanding how the activity of neural circuits contributes to perception and behavior requires recording neuronal activity in the awake animal. The oldest method for such recording is electrophysiology, whereby implanted electrodes can record changes in voltage induced by neuronal activity. Electrophysiology drove the field of neuroscience forward for two centuries, and greatly enriched our understanding of how neurons and the brain work. More recently, another avenue for recording neuronal activity has seen exciting development: optical methods.Optical methods for recording in vivo neuronal activity allow researchers to record the activity of large populations of neurons at single cell resolution using fluorescence microscopy. Additionally, optical methods for modulating neuronal activity allow researchers to further probe the role of specific neurons or neural circuits in behavior and perception. However, optical methods also have their limitations, and miss out on valuable data provided by electrophysiology. The goal of the work presented in this dissertation is to provide neuroscience researchers with a novel device that allows them to collect both data types, optical and electrical, and provide motivation for doing so.In this dissertation I describe the creation of a neural implant designed to provide simultaneous in vivo optical and electrical recording of neuronal activity in mice. The design of the neural implant allows for recording from head-fixed animals, as well as freely moving animal by coupling the imaging system to an optical fiber. Additionally, I perform correlation analysis which demonstrates positive correlation between optical and electrical recordings.The first two chapters of this dissertation provide background for the use of electrophysiology and neuronal imaging, and present motivation for the combination of these recording modalities. The third chapter covers the current state of bimodal recording methods. In the fourth chapter I present my work developing a neural implant to provide simultaneous multiphoton imaging and extracellular electrophysiology in head-fixed and fiber coupled freely moving mice, provide data demonstrating the successful use of this device, and provide correlation analysis between optically and electrically recorded data. The fifth chapter discusses conclusions and future directions, and further details the need for multimodal recording methods to investigate neural activity and continue pushing the field of neuroscience forward.