What mechanism underlies glutamate excitotoxicity?

• A. Ca2+ efflux through NMDA triggers protective pathways.
• B. Excess glutamate causes overactivation of NMDA/AMPA receptors, Ca2+ influx, activating enzymes leading to cell damage and death.
• C. Glutamate excitotoxicity is caused by oxidative stress in neurons.
• D. Reduced Ca2+ influx leading to neuron survival.

Answer: (C)