@article{2acf1795891d44fca8dd5940a08d2504,
title = "Sound exposure dynamically induces dopamine synthesis in cholinergic LOC efferents for feedback to auditory nerve fibers",
abstract = "Lateral olivocochlear (LOC) efferent neurons modulate auditory nerve fiber (ANF) activity using a large repertoire of neurotransmitters, including dopamine (DA) and acetylcholine (ACh). Little is known about how individual neurotransmitter systems are differentially utilized in response to the ever-changing acoustic environment. Here we present quantitative evidence in rodents that the dopaminergic LOC input to ANFs is dynamically regulated according to the animal{\textquoteright}s recent acoustic experience. Sound exposure upregulates tyrosine hydroxylase, an enzyme responsible for dopamine synthesis, in cholinergic LOC intrinsic neurons, suggesting that individual LOC neurons might at times co-release ACh and DA. We further demonstrate that dopamine down-regulates ANF firing rates by reducing both the hair cell release rate and the size of synaptic events. Collectively, our results suggest that LOC intrinsic neurons can undergo on-demand neurotransmitter re-specification to re-calibrate ANF activity, adjust the gain at hair cell/ANF synapses, and possibly to protect these synapses from noise damage.",
keywords = "Auditory nerve fiber, Dopamine, Noise damage, Olivocochlear lateral efferents",
author = "Wu, {Jingjing Sherry} and Eunyoung Yi and Marco Manca and Hamad Javaid and Lauer, {Amanda M.} and Elisabeth Glowatzki",
note = "Funding Information: Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic Funding Information: This work is supported by a National Institute on Deafness and Other Communication Disorders grant P30 DC005211 to the Center for Hearing and Balance at Johns Hopkins. Additional support for the statistical analysis is from the National Center for Research Resources and the National Center for Advancing Translational Sciences (NCATS) of the National Institutes of Health through Grant Number 1UL1TR001079. We thank Brian McGuire for contributing to sample processing and data analysis. We thank Kristina Jones for contributing to the quantification of the TH+ LOC intrinsic neurons. We thank Timothy Phelps for making the illustrations in Figure 1. This work was supported by a National Institute on Deafness and Other Communication Disorders grants R01DC006476 and R01DC012957 to EG; R01DC017620 and R01DC016641 to AML; the David M. Rubenstein Fund for Hearing Research, the Capita Foundation to AML. This work is also supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI17C0952) to EY. Funding Information: This work is supported by a National Institute on Deafness and Other Communication Disorders Funding Information: Grant Number 1UL1TR001079. We thank Brian McGuire for contributing to sample processing Funding Information: also supported by a grant of the Korea Health Technology R&D Project through the Korea Health Publisher Copyright: {\textcopyright} 2020, eLife Sciences Publications Ltd. All rights reserved.",
year = "2020",
month = jan,
doi = "10.7554/eLife.52419",
language = "English (US)",
volume = "9",
journal = "eLife",
issn = "2050-084X",
publisher = "eLife Sciences Publications",
}