Don brain cells die after a few minutes without oxygen ?
No. The initial damage due to ischemia (loss of blood circulation causing deprivation of nutrient and oxygen) and reperfusion (restoration of circulation) is to blood vessels − and most of the damage is due to reperfusion, not ischemia. At low temperatures the brain can undergo much longer ischemic periods before experiencing damage − even to blood vessels. At room temperature brain cells can go many hours before dying − although they may be set onto a currently irreversible path of self-destruction (apoptosis) which will take many hours or a few days to complete. By lowering temperature the self-destructive process is greatly slowed, and may be eliminated when cryonicists can restore circulation after legal death. The apoptosis process that is irreversible by current technology could well be reversible by future molecular medicine. (For more information on this subject, see Minimizing Ischemic Damage to Cryonics Patients .
No. The initial damage due to ischemia (loss of blood circulation causing deprivation of nutrient and oxygen) and reperfusion (restoration of circulation) is to blood vessels − and most of the damage is due to reperfusion, not ischemia. At low temperatures the brain can undergo much longer ischemic periods before experiencing damage − even to blood vessels. At room temperature brain cells can go many hours before dying − although they may be set onto a currently irreversible path of self-destruction (apoptosis) which will take many hours or a few days to complete. By lowering temperature the self-destructive process is greatly slowed, and may be eliminated when cryonicists can restore circulation after legal death. The apoptosis process that is irreversible by current technology could well be reversible by future molecular medicine.
