Calpain...

..AND HIS TRUSTY BLADE FUBARING, SWORD OF MAYHEM

We have seen that, during early ischemia, calcium floods into the cell from the interstitium and endoplasmic reticulum due to the loss of ATP and cellular pumps. And we have seen that this flood of calcium triggers lipolysis and the vicious sequelae of oxidative stress. But the damage of calcium flux goes beyond all that.  The surge in calcium transforms the protease calpain from an essential player in the remodeling of neurites and synapses to a badass berserker with an attitude.