Sharon Lu
Research Mentor: Not Available Not Available
Mentor Department: Not Available, Not Available
Author(s): Not Available
Session: Session 2 (10:00 AM – 10:50 AM)
Presentation Type: Poster 2
Abstract
The Inferior Colliculus (IC) is a central auditory structure located in the midbrain and plays a significant role in speech processing, sound localization, and sensory gating by integrating ascending sensory information and descending cortical feedback. Yet, we don’t fully understand how individual neurons or networks within the IC process sound or how neurotransmitters in this system contribute to sensory gating.
Acetylcholine (ACh) is a critical neuromodulator that functions as a gain controller for sensory stimuli in cortical regions (Kunnath et al., 2023). However, little is known about its potential modulation of the IC. ACh is released by cholinergic neurons and binds to either nicotinic (ionotropic) or muscarinic (metabotropic) receptors.
The goal of this project is to determine the adequate titration of a novel ACh sensor in the inferior colliculus. This virus is an adeno-associated viral (AAV) serotype 9 with a synapsin promoter, specifically known as AAV9-hSyn-GRAB_ACh3.0. GRABACh labels all neurons in the injection region with an artificial acetylcholine receptor sensor that drives the expression of GFP when ACh is bound. This enables acetylcholine to bind to the modified G-protein-coupled receptor and trigger a signaling cascade, causing a conformational change of GFP. And, from this conformational switch, we can detect changes in fluorescence intensity, which is correlated to ACh release in the region of interest. Because this novel GRABACh has yet to be utilized in the IC, we are exploring which concentration of viral particles will yield optimal brightness while maintaining neuronal health.
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