Presenter(s): Nadav Menashe
Faculty Mentor(s): Santiago Jaramillo
Poster 20
Session: Sciences
For years, researchers have been trying to uncover how different auditory areas in the brain allow us to segregate signals from a noise. The goal of this study was to use a mouse model to understand how two types of cortical inhibitory interneurons found in the auditory cortex, known as somatostatin-expressing (SOM) and parvalbumin-expressing (PV) interneurons, contribute to our perception of sound masked by noise. We hypothesized that suppressing the activity of auditory cortical SOM interneurons would decrease a mouse’s ability to detect a tone masked by noise when the background noise was composed of broadband signals. We expected a similar decrease when PV interneurons were suppressed when the background noise was composed of narrowband signals. To test these hypotheses, we taught transgenic SOM-ArchT and PV-ArchT mice how to perform a behavioral task where they had to determine if a pure tone was present in background noise. We then implanted optical fibers over their auditory cortex and they performed the same task while having their respective interneurons suppressed through an interaction between the light-sensitive ArchT protein and green light. We found that suppressing SOM interneurons decreased the percentage of trials in which the mice were able to detect a tone in all bandwidths of background noise, while suppressing PV interneurons did not affect performance, showing that they might not be important for mice to perform this task. These findings allow us to better understand the roles that different sources of inhibition play when detecting a sound masked by noise.