Table 2.

Acidic extracellular pH increases the contribution of AMPA–kainate receptors to oxygen–glucose deprivation injury

Treatment	% Neuronal death ± SEM
pH 7.4
OGD (50 min)	65  ± 3
OGD (50 min) + NBQX	66  ± 5
pH 6.4
OGD (75 min)	84  ± 6
OGD (75 min) + NBQX	63  ± 6*

Addition of 30 μm NBQX did not reduce neuronal death in cultures exposed to 50 min of oxygen-glucose deprivation at pH 7.4 but did partially reduce neuronal death in cultures exposed to oxygen–glucose deprivation at pH 6.4. Because reducing pH reduced NMDA receptor-mediated toxicity and overall neuronal death, in the latter condition the duration of oxygen–glucose deprivation was increased to 75 min to recover widespread neuronal death comparable to corresponding injury with 50 min oxygen–glucose deprivation at pH 7.4. Data are mean ± SEM (n = 8). Neuronal cell death was quantitated by measuring LDH released into the bathing medium 24 hr later.

*Difference at p < 0.05 from 75 min oxygen–glucose deprivation at pH 6.4, by Student’s two-tailed independentt test.