Dear Ananya,

Are you working on neuronal cultures, on slice preps (like above), or in vivo?

I only have experience with excitotoxicity in mouse cortical cultures, and that was a very long time ago.  I believe there are detailed methods available in Methods in Neuroscience (I can't link at this time).  There are also the classic papers from Dennis Choi's lab, which we used as the basis for our protocols.

If you are working on cortical cultures derived from E14-E18 mice, the neurons must mature in vitro to be responsive to NMDA (that is, undergo death due to excitotoxicity)  We would start testing the cultures at about 10 DIV with an NMDA challenge. We usually reliably used our cultures at 14 DIV for our work.

Good Luck!

Jill