The N-methyl D-aspartate receptor is one of the key receptors in the human brain. As a result of radioligand analysis, it was found that the highest density of this receptor is located in the hippocampus, striatum, cortex, and amygdala. Associative memory, learning, and synaptic density are all directly related to the effective functioning of the NMDA receptor. Recent studies have shown that the number of NMDA receptors and their morphological structure decreases with age, in particular, some subunits change their shape, as well as the use of antidepressants, such as selective serotonin reuptake inhibitors, cause a delayed side effect, which manifests itself in the form of a quantitative decrease in NMDA in the brain. The antagonist of this receptor - memantine, inhibiting it can reduce the clinical picture of Alzheimer's disease, reducing tremor and papillary reflex. Another NMDA antagonist, ketamine, was used for anesthesia, but due to strong hallucinations during the period of recovery from anesthesia, it became less and less used. These substances also contribute to the work of the NMDA receptor in the future, and also affect synaptic density. Therefore, it is important to know the composition of the receptor, its downstream signaling pathways, and age-related changes in order to effectively prevent neurodegenerative diseases of the brain.