The aim of this research was to determine the influence of anesthesia, drugs, and neurosurgical trauma on the permeability of the blood-brain barrier (BBB) for macromolecules. Protein markers of oligodendrocytes and astroglia were used. The research methods were unique. Two groups of patients were formed: with neurosurgical brain trauma and without it. Everyone in both groups was subjected to anesthesia. The results were unexpected and did not depend on surgery: 1. Neurosurgical brain trauma did not change the permeability of BBB. 2. Anesthesia resulted in increasing permeability of BBB with peak upon 24-48 h. 3. High blood levels of neurospecific proteins proved protein synthesis in glial cells. 4. Massive transferring of brain antigens into blood did not stimulate antibody synthesis during a period of 21 d. According to the high blood levels of neural proteins, the antigen-antibody reaction took place in blood and autoimmune complexes were eliminated before penetration into the brain. A new mechanism of brain autoimmune safety is discussed.