Glutamate decarboxylase (GAD) plays a key role in the inner ear by regulating levels of the neurotransmitter GABA, which is synthesized from glutamate. GABA acts as the primary inhibitory neurotransmitter in the nervous system. This is especially relevant in the cochlea and vestibular organs, where overactivation of glutamate receptors can damage hair cells and neurons, contributing to hearing loss and balance disorders. This project is an extension of training at the Massachusetts Eye and Ear (NIDCD National Temporal Bone, Hearing, and Balance Pathology Resource Registry.