Marina Silveira, Ph.D.
The Research
University of Texas at San Antonio
Age-related changes in neuromodulatory signaling in the auditory midbrain
Age-related hearing loss is the most common form of hearing loss in older adults. Age-related hearing loss causes difficulty understanding speech in noisy environments. Consequently, hearing loss has a major negative impact on quality of life and leads to social isolation, loneliness, and is a significant risk factor for dementia and Alzheimer’s. It is well known that age-related hearing loss shifts the excitatory-inhibitory balance in the inferior colliculus to favor excitability. This enhancement in excitability can contribute to pathological conditions such as tinnitus and poor temporal processing. However, the mechanisms that regulate this enhanced excitability in the inferior colliculus are unclear. A major neuromodulator called serotonin has been shown to regulate the excitatory-inhibitory balance in other brain regions. In preliminary studies for this proposal, we found that serotonin strongly influences the activity of a class of inhibitory neurons in the inferior colliculus that express neuropeptide Y. Here, we will test the hypothesis that dysfunction in serotonergic and neuropeptide Y signaling underlies enhanced excitability in the inferior colliculus in age-related hearing loss. Because the serotonergic system is a common target for pharmaceuticals, our results will also provide foundational insights that might guide future pharmacological interventions for age-related hearing loss.
Long-term goal: Our long-term goal is to determine how neuromodulatory inputs alter neural networks in the central auditory pathway, providing a mechanistic foundation for the development of neuromodulatory therapeutic agents that aim to improve hearing for the hearing-impaired.
Generously funded by Royal Arch Research Assistance
