Sarah Wajdi
Pronouns: she/her
Research Mentor(s): Michael Roberts
Research Mentor School/College/Department: Otolaryngology-Head and Neck Surgery / Medicine
Program: UROPF
Session: Session 5 (2:40pm – 3:30pm)
Authors: Sarah Wajdi, Audrey Drotos, Michael Roberts
Abstract
The inferior colliculus (IC) plays a significant role in complex sound processing in the brain, where it integrates information in the auditory pathway. More specifically, the IC is important for processing complex sounds such as vocalizations and frequency-specific information, and IC neurons also show selectivity for directional frequency sweeps. These frequency sweeps are an important component of vocalizations, yet how selectivity in responses to frequency sweeps arises in the IC remains unknown. We hypothesize that neuron selectivity for frequency sweeps is generated due to asymmetries in a neuron’s frequency response area (FRA). To test this, we performed in vivo juxtacellular recordings from the IC in awake head fixed mice while playing frequency sweeps of different durations and speeds over varying octaves. We also assessed the frequency tuning of each neuron using pure tones played at different sound levels. Through these recordings, we found a wide variety of responses, with some IC neurons being tuned to upward or downward sweeps, some experiencing inhibition during sweep presentation, and others not responding at all. Additionally, we found that sweep selectivity can be predicted by the excitatory and inhibitory areas found in a neuron’s FRA. These observations provide a framework for understanding how certain IC neurons encode frequency sweeps in vocalizations, and highlight the importance of understanding tuning to frequency sweeps in complex sound processing.
