Presenter: Ulysses Duckler
Faculty Mentor: Mike Wehr, Aldis Weible
Presentation Type: Poster 92
Primary Research Area: Science
Major: Biochemistry
Funding Source: OURS Summer Research Program
Strong evidence supports that hearing loss and difficulty with speech comprehension in noisy environments for older adults is the result of temporal processing deficits in central auditory structures such as the auditory cortex. There is a general canonical circuit model of layer by layer serial information flow through the auditory cortex from the thalamus, before information is projected back into inferior colliculus neurons. However the specific cortical circuits and cell types which regulate temporal processing though the auditory cortex are still unknown and not linked to behavior. The auditory cortex is necessary for temporal acuity in receiving auditory stimulus. Temporal acuity is necessary for brief noise gap detection and discriminating between similar phonemes, causing speech perception deficits when impaired. In this study, I tested gap detection in mice by measuring their startle response to noise gaps in white noise, gaps which were paired with a startle stimulus in repeated behavioral trials. The presence of the noise gap attenuates startle response to the stimulus, so that measuring the startle response gives a measure of temporal acuity by assessing gap detection behavior. Optogenetics allows for the gaps to be paired with a laser signal that silences auditory cortex neurons and allowed me to see how gap detection is impaired by temporally precise auditory cortex neuron suppression. By probing cortex circuit mechanisms through layer specific optogenetic silencing before and after gap, I found that layer specific silencing of auditory cortex neuron populations in layers four and five suggests behavior in accordance with the canonical model.