CNQX is widely used in neuroscience research as a selective antagonist for AMPA receptors, which are crucial for fast synaptic transmission in the central nervous system. By blocking these receptors, CNQX helps scientists study the role of AMPA receptors in various neurological processes, including synaptic plasticity, learning, and memory. It is also utilized in experiments to investigate excitotoxicity, a process where excessive glutamate activity leads to neuronal damage, which is relevant in conditions like stroke and neurodegenerative diseases. Additionally, CNQX is employed in electrophysiological studies to isolate and analyze other types of glutamate receptors, such as NMDA receptors, by selectively inhibiting AMPA receptor activity. This makes it a valuable tool for understanding the complex mechanisms of brain function and dysfunction.