Electrochemical methods were developed by analytical chemists in the late 1950’s to analyze the oxidation and reduction reactions of numerous electrochemical compounds reacting at the surface of various types of recording electrodes. Since then, these electrochemical recording techniques have become standard analytical methods for quantifying femto (10-15) to milli (10-3) molar concentrations of electrochemical compounds in both aqueous and non-aqueous solutions. It was not until the mid-1970’s that two electroanalytical chemists, Dr. Ralph (Buzz) Adams at the University of Kansas and Dr. Ross Lane at the University of California at Santa Barbara (my PhD mentor), investigated the possibility of applying electrochemical methods to measure the concentrations of electroactive neurochemicals in the mammalian brain (rodent) in vivo at the surface of micro-miniaturized carbon-tipped electrodes. These electroactive neurochemicals happened to be important classes of neurotransmitters, namely the catecholamines (dopamine and norepinephrine) and indolamines (serotonin), which are intimately involved in the normal regulation of motor control, mood, attention, motivation, and cognition, whereas dysregulation of these transmitters is associated with neuropsychiatric disorders (Parkinson’s disease, depression, and schizophrenia). These early studies provided an early lesson in the importance of selectivity and the need to identify and confirm the chemical source of oxidation currents recorded in the brain. By the late 1990’s the issue of chemical selectivity had been adequately addressed mainly by the development of new electrochemical (voltammetry) techniques and recording electrodes. This renaissance period has led to the present day application of voltammetry as the principle analytic method to quantify, in real time, neurotransmitter release in the mammalian brain. This tutorial will cover the history and electrochemical principles of in vivo voltammetry as they are applied to elucidate the role of catecholamines and indolamine neurotransmission in neurologic disease and normal and abnormal behaviors.
Charles D. Blaha, Ph.D.
Dr. Blaha is currently a Professor of Neurologic Surgery at the Mayo Clinic and was previously a long-time collaborator of the Mayo Clinic Neural Engineering Laboratories (NEL), a role that started in his former position as a distinguished full professor in the Department of Psychology at the University of Memphis in Tennessee since 2004. He has extensive research experience in the discipline of Systems Neuroscience and more specifically in the areas of neurochemistry, neuropharmacology, neuroanatomy, and electrochemical theory, methodology, and applications to quantifying neurotransmitter release in the brain. Over the last 30 years he has published over 130 papers on the development and application of state-of-the-art in vivo electroanalytical recording procedures to quantify drug-evoked and electrically stimulated neurotransmitter release in the mammalian central nervous system (rodents, swine, non-human primates, and humans). Dr. Blaha joined Mayo Clinic full time in 2015 as the Associate Director of Research for Mayo Clinic NEL.