Perineuronal nets (PNNs) are specialized condensations of extracellular matrix that surround the somata of neurons throughout the brain. Because PNNs surround fast-spiking neurons and are highly negatively charged, it has been proposed that they act as a buffering system for cations, supporting fast and precise action potential generation. Electrophysiological recordings paired with enzymatic digestion of PNNs will allow me to test the role of PNNs in supporting fast-spiking and timing accuracy, and buffering potassium ions that contribute to fast repolarization of action potentials. These experiments will identify how PNNs contribute to neuronal function and how PNNs could contribute to pathologies of neuronal activity such as epilepsy.