Electroanalytical Tools and Biochemical Assays to Measure the Impact of Noise on Dopamine Neurotransmission in the Central Auditory Pathway

In the United States, loss of hearing impacts approximately 48.1 million people. The cumulative effects of noise are experienced in every area of society whether occupational, environmental, or through aging. Previous work has reported changes in dopamine receptor gene expression following acoustic trauma, suggesting a possible role of dopamine in auditory processing. This conclusion is supported by recent data that showed patients suffering from Parkinson’s disease (a condition associated with dopamine depletion) exhibit deficits in auditory processing. Thus, the present work focuses on the role of dopamine neurotransmission within the central auditory pathway and how it’s impacted by noise exposure. Characterizing the complexities of neurotransmission requires elegant methods of inquiry, regarding both the neurotransmitter and neuron physiology. Fast scan cyclic voltammetry (FSCV) with carbon fiber microelectrodes is uniquely well-suited for real time neurochemical measurement because it has the speed, selectivity, sensitivity, and the spatial resolution needed for such measurements. Immunoassays on the other hand provides information about the neural protein receptors distribution and levels. In this work, dopamine neurotransmission release and uptake events are characterized and quantified with FSCV in the inferior colliculus in vitro and in vivo comparing sound exposed and control groups. Additionally, immunocytochemistry (ICC) and Western blot are utilized to evaluate the effects that damaging sound on dopamine receptors within the inferior colliculus. The combination of FSCV and immunoassays provide a comprehensive examination of the role of dopamine and the repercussions of noise in the central auditory pathway.