Neural Circuits Facilitating Signal Detection in the Auditory Cortex

Abstract

The natural acoustic environment is very noisy, with sounds coming from many sources and containing many overlapping frequency components. To navigate this environment, it is necessary for animals to be able to decompose this auditory stream of information into behaviorally relevant signals and irrelevant background noise. However, the mechanisms by which this separation takes place in the auditory system is not fully understood. In this dissertation, I investigated the role of auditory cortical circuits in signal detection. In Chapter II, I describe our findings that somatostatin-expressing inhibitory interneurons mediate spectral surround suppression, a form of global integration that may be useful for suppression of responses to broadband noise. In Chapter III, I found that the auditory cortex plays an important role in the perception of stimuli immersed in noise, and that perturbation of inhibitory interneurons reduces an animal's ability to detect a masked signal. Together, these works expand our knowledge of the neural computations taking place in the sensory cortex that allow for the separation of signals from noise.

This dissertation includes previously published co-authored material.