Robert Fyffe (Advisor)
Master of Science (MS)
This experiment analyzes synaptic differences in the central auditory pathway between normal hearing and congenitally deaf (dn/dn) mice, and provides valuable insight into central changes that correspond with human congenital deafness. Specifically, this experiment analyzes developmental expression of the Calcium (Ca2+)-binding proteins Calretinin (CR), Calbindin D-28k (CB) and Parvalbumin (PV) in large excitatory synapses in the anteroventral cochlear nucleus (AVCN) and the medial nucleus of the trapezoid body (MNTB) of normal and dn/dn mice. Immunofluorescence imaging with primary antibodies detecting CR, CB or PV was used to analyze the expression of each at 9 days, 13 days, 20 days, 30 days and 49 days postnatal in normal and dn/dn mice. Results indicated that Ca2+-binding expression was similar at each location in normal and dn/dn mice at 9 days postnatal, prior to opening of the ear canal and the onset of hearing (which occurs around 11 days postnatal) . In normal mice, patterns of Ca2+-binding protein expression changed progressively after the onset of hearing. In dn/dn mice (which completely lack auditory nerve activity), however, patterns of expression did not change after the onset of hearing, suggesting that patterns of Ca2+-binding protein expression change during development in normal mice in response to evoked auditory nerve activity, and that patterns of Ca2+-binding protein expression do not change during development in dn/dn mice due to lack of evoked auditory nerve activity. As a result, Ca2+ buffering is impaired in synapses located in the AVCN and MNTB of dn/dn mice.
Department or Program
Department of Neuroscience, Cell Biology & Physiology
Year Degree Awarded
Copyright 2006, all rights reserved. This open access ETD is published by Wright State University and OhioLINK.