This question could be considered a follow-up question to Why is a lack of oxygen fatal to cells?, although the top answer there does not address why damage starts to pop in.
The answer says this:
Neurons are also highly metabolically active, which means they generate more waste products. A buildup of nitrogenous waste products in the cell (and bloodstream) can be potentially fatal due to it's effects on pH (screws up enzymes and a whole slew of biochemical reactions)
But when the brain is deprived of oxygen, metabolism shuts down. So waste products aren't being generated anymore.
Basically I'm wondering - what causes neurons, in particular, to die so quickly (relative to other cells, like kidney cells) after they're depleted of energy?