N-methyl-D-aspartate (NMDA) receptors are a type of glutamate receptor found in the brain. They play a crucial role in synaptic plasticity, which is essential for learning and memory. NMDA receptors are unique because they require both the binding of the neurotransmitter glutamate and a change in voltage across the cell membrane to become activated. These receptors are also involved in various neurological processes and can influence the development of certain conditions, such as Alzheimer's disease and schizophrenia. Dysfunction in NMDA receptor activity can lead to impaired cognitive functions and has been a target for research in developing new treatments for these disorders.