D-serine is an amino acid that plays a crucial role in the brain as a co-agonist of the N-methyl-D-aspartate (NMDA) receptor. It helps facilitate the transmission of signals between nerve cells, which is essential for processes like learning and memory. D-serine is produced naturally in the body and can also be found in certain foods. Research suggests that it may be involved in various neurological conditions, including schizophrenia and Alzheimer's disease, making it a topic of interest for scientists studying brain health and function.