Our Research

Descending Auditory Pathways: A major advance over the past 25 years has been the discovery of extensive pathways from auditory cortex to many lower brainstem auditory regions. Many of our studies have focused on identifying the auditory circuits that are contacted directly by the descending projections from auditory cortex. Another important focus of this work is the interaction between descending auditory pathways and neuromodulatory pathways.

Cholinergic Circuits: Acetylcholine is a neurotransmitter that is important in normal hearing, development, aging, learning, and after damage to the nervous system. Understanding these functions is critical for developing approaches to help people with age-related hearing loss, difficulty understanding speech in noisy environments, learning to hear with cochlear implants or coping with hearing dysfunctions in disorders such as autism or schizophrenia. Our work will answer critical questions about the circuitry that underlies cholinergic function in the brainstem.

Types of Inhibitory Cells: Inhibitory neurons that use GABA or glycine as a neurotransmitter play key roles throughout the auditory system. Another area of emphasis in our lab focuses on several questions about these inhibitory cells: 1) are there specific molecular markers that distinguish subtypes of inhibitory cells that serve different functions in hearing? 2) do top-down circuits have direct connections with the inhibitory cells? 3) do cholinergic circuits have direct connections with the inhibitory cells?

Circuitry of Subclasses of Inferior Colliculus Cells: Recent collaborative work with the Roberts lab has shown that two markers, vasoactive intestinal peptide, or VIP, and neuropeptide Y, or NPY, can be used to identify distinct subclasses of cells in the inferior colliculus, an auditory hub. We are working to understand what brain regions send inputs to these cell types, and to find out what brain regions these cell types send projections to.