The p75 neurotrophin receptor (p75^NTR) is a versatile receptor involved in regulating neuronal growth, survival, and apoptosis, primarily through its interaction with neurotrophins like NGF, BDNF, NT-3, and NT-4. It plays a critical role in nervous system development and response to injury, often modulating the effects of the Trk receptor family and influencing cellular outcomes based on the cellular context and ligand availability.