The goals of this study will be to investigate the synaptic properties of auditory cortical synapses, in order to assess their putative roles in auditory information processing. The broad objectives of this research are to understand the functional contributions of these projections to auditory perception and behavior and how changes in these synaptic properties manifest with age and in disease processes. I have already identified several anatomical and physiological properties of glutamatergic synapses in the central auditory system, which forms the basis for the proposed investigation. This study will utilize an in vitro slice preparation in the mouse, which has been developed for the auditory cortical pathways. Whole-cell recordings in cortical neurons will be used to record responses to minimal electrical stimulation, photostimulation by uncaging of glutamate, and photostimulation of channelrhodopsin expressing fibers in order to characterize their topographic organization and physiological properties. In addition, a novel method of optical imaging of responses revealed by autofluorescence will be employed to help trace the output patterns of auditory cortical projections. Morphological correlates will be sought using intracellular injections of biocytin. The proposed experiments should lead to further insight on the information-bearing roles of the auditory cortical projections, as well as help to establish their relative weights in the organization of central processing in the auditory system.

Public Health Relevance

This study should enhance our knowledge and perspective of the normal modes of information processing in the auditory system. It should provide a foundation for the further exploration of abnormal processing in auditory neurological diseases and aging, which will eventually lead to improved diagnostics and treatments for patients with disorders of the auditory system.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Small Research Grants (R03)
Project #
5R03DC011361-04
Application #
8374413
Study Section
Special Emphasis Panel (ZDC1-SRB-Y (56))
Program Officer
Platt, Christopher
Project Start
2010-12-01
Project End
2014-11-30
Budget Start
2012-12-01
Budget End
2014-11-30
Support Year
4
Fiscal Year
2013
Total Cost
$140,600
Indirect Cost
$45,600
Name
Louisiana State University A&M Col Baton Rouge
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
075050765
City
Baton Rouge
State
LA
Country
United States
Zip Code
70803
Venkatadri, Pooja S; Lee, Charles C (2014) Differential expression of mGluR2 in the developing cerebral cortex of the mouse. J Biomed Sci Eng 7:1030-1037
Lee, Charles C (2014) Two types of auditory glutamatergic synapses and their implications for repairing damaged central auditory pathways. Neural Regen Res 9:1000-2
Lee, Charles C (2013) Thalamic and cortical pathways supporting auditory processing. Brain Lang 126:22-8
Lee, Charles C; Kishan, Amar U; Winer, Jeffery A (2011) Wiring of divergent networks in the central auditory system. Front Neuroanat 5:46
Lee, Charles C; Sherman, S Murray (2011) On the classification of pathways in the auditory midbrain, thalamus, and cortex. Hear Res 276:79-87
Lee, Charles C; Winer, Jeffery A (2011) Convergence of thalamic and cortical pathways in cat auditory cortex. Hear Res 274:85-94