DL-AP3 is primarily used in neuroscience research as a selective antagonist for group I metabotropic glutamate receptors (mGluRs). It helps in studying the role of these receptors in synaptic transmission, plasticity, and neuronal excitability. By blocking mGluR1 and mGluR5, DL-AP3 allows researchers to investigate their involvement in various neurological disorders, such as epilepsy, Parkinson's disease, and chronic pain. Additionally, it is utilized in experimental models to understand the mechanisms underlying learning and memory processes. Its application is crucial for developing targeted therapies for conditions linked to glutamate receptor dysfunction.