Excitotoxicity is a process in which neuronal synapses are destroyed by overstimulation by excessive release of the neurotransmitter glutamate. In the brain this can result in the death of neurons. Loud noise can cause excitotoxic destruction of synatpses (“synaptopathy”) in the cochlea by excessive release of glutamate from the auditory sensory cells. This results in hearing impairment. The synapses can be protected from pharmacological protection from sudden loud noise and preliminary experiments using mice have yielded promising results. To expedite these studies, the Green lab has developed an in vitro system for studying excitotoxic trauma in the cochlea by a brief application of the glutamate agonist kainic acid (KA) in culture. In our current experiments we are optimizing this system by identifying the optimal concentration of KA. In these experiments, we add KA at different concentrations and subsequently fix the cultures, label the synapses by immunofluorenscence and count remaining synapses.