But at an hour and twenty minutes you've really gotta be dedicated (OK, obsessed) so, here is the synoposis-

Neurons don't just die. They sort of have bad days where a series of things go wrong. Normally they can recover from, say, that whiff of pesticide. Or that hypoglycemic episode. Or half-a-dozen other "insults."

Each of those insults is actually a short chain of events (the ever-popular "cascade"), maybe five or six. But we can usually handle it. However, if we are awash in gluccocorticoids (i.e. cortisol) each of those events is amplified and once each step in the chain is ramped up you no longer have a recovering neuron you have a dead one. So, chill!