Development and Function of Inhibitory Circuitry in the Avian Auditory Brainstem
The avian auditory system has provided an excellent model circuit to explore important features of acoustic processing. For example, in the chicken (Gallus gallus) system, in 1975 Parks and Rubel first confirmed the coincidence detection based delay line model of sound localization in vertebrates that was originally proposed by Jeffress in 1948. Further, the system provides an unmatched experimental substrate to investigate cellular physiology and morphology in light of computational function. Many anatomical and physiologically specialized features of auditory neurons have been identified first in birds, and often complementary properties are observed in mammals. These discoveries have contributed substantially to our general understanding of processing of acoustic signals, and the function of inhibition specifically. However, many mechanistic features of inhibitory physiology in the avian system contrast sharply with those of mammals, while achieving similar computational outcomes. This chapter reviews the major progress made toward understanding inhibitory roles in auditory function with a focus on three areas: (1) development of inhibitory circuitry, (2) functional organization of the inhibitory network, and (3) synaptic physiology of inhibition in birds. Although many specific mechanisms of inhibition in birds differ from those of mammals, these circuits exhibit remarkable convergence when viewed from a functional perspective.
KeywordsBinaural Corelease Depolarizing inhibition GABA Superior olivary nucleus
Above all, I would like to thank my mentor and friend, Ed Rubel. Thank you for demonstrating high expectations, while never losing sight of science as a joyful pursuit. I would also like to thank the many colleagues who have contributed the work referenced in this chapter for continuing to inspire my own.
Compliance with Ethics Requirements
R. Michael Burger declares that he has no conflict of interest.
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