Vasopressin V1a receptor neurons represent a specialized population of hypothalamic neurons that express the V1a subtype of vasopressin receptors. These neurons play critical roles in regulating osmotic homeostasis, cardiovascular function, stress responses, and social behavior. The V1a receptor (AVPR1A) is a G protein-coupled receptor (GPCR) that activates phospholipase C signaling pathways, leading to increased intracellular calcium and diverse physiological effects. Recent research has revealed important connections between vasopressinergic signaling and neurodegenerative processes in conditions such as Alzheimer's disease and Parkinson's disease.