Oxidative stress is one of the major characteristics in Alzheimer’s disease, and converging evidence indicates that cysteine S-nitrosylation might be related in AD pathology. My results demonstrated exogenous S-nitrosoglutathione was able to S-nitrosylate vAChT, vMAT2, vGluT1 and vGluT2. S-nitrosylation of these vesicular transporters inhibited the uptake of [3H]acetylcholine, [3H]dopamine and [3H]glutamate respectively. APP/PS1 transgenic mice were used to investigate neurotransmission dysfunctions of Alzheimer’s disease. Global protein S-nitrosylation was increased in the 9 and 12 month APP/PS1 mice. Further investigation demonstrated an increase of vAChT and vGluT1 S-nitrosylation in frontal cortex of 6, 9 and 12 month APP/PS1 mice and an increased vAChT and vGluT1 S-nitrosylation was found in hippocampus of 3 month APP/PS1 mice. These findings together suggest that S-nitrosylation of vesicular transporters inhibits the uptake of neurotransmitters, and S-nitrosylation of vAChT and might be associated with the neurotransmission dysfunction of acetylcholine and glutamate in Alzheimer’s disease.

<p>The lateral superior olive (LSO) is a binaural nucleus that is critical for azimuthal sound localization. Bipolar principal cells of the LSO compute interaural level differences (ILDs) by comparing converging excitatory and inhibitory inputs driven by either ear. More specifically, this computation relies on integrating excitatory inputs from the ipsilateral cochlear nucleus with inhibitory, GABA/glycinergic inputs from the medial nucleus of the trapezoid body (MNTB), which are driven by sound originating at the contralateral ear. In order to reliably compute ILDs, the converging inputs must represent sounds of the same frequency. This specificity emerges during the first few weeks of postnatal life in rats as a result of functional and anatomical refinement. Interestingly, significant refinement of this auditory circuit occurs in the absence auditory experience. We focused on changes in the subcellular location of MNTB inputs and the expression of vesicular proteins before hearing onset.</p> <p>The subcellular distribution of inputs onto a neuron heavily influences synaptic integration and the mature distribution likely emerges during a period of circuit refinement. Little is known about how the inputs are distributed onto LSO principal cells and how the mature distribution is achieved. We studied the distribution of inhibitory inputs onto LSO neurons and found that significant re- distribution occurs before hearing onset. The mechanisms underlying the refinement of the inhibitory MNTB projection are not well understood but could be related to the transient co-transmission of the excitatory neurotransmitter glutamate. We studied the expression of vesicular proteins that may regulate the release of GABA/glycine and glutamate at the immature MNTB terminal. We found that MNTB terminals transiently express two Ca++ sensors, which may be associated with the different release properties for GABA/glycine and glutamate. Lastly, we asked one specific example of what controls the expression and sorting of vesicular proteins at the immature MNTB terminal.</p> / Doctor of Philosophy (PhD)