Effects of acidosis on the post-hypoxic recovery of synaptic transmission in gerbil hippocampal slices

We investigated the effects of acidosis on the hypoxic neuronal damage usin g gerbil hippocampal slices. Acidosis has delayed the onset of harmful hypo xic depolarization. resulting in a decrease in the total hypoxic period and the hypoxic depolarization. This effect has been considered to be protecti ve. However, the synaptic recovery after reoxygenation was attenuated when acidosis (pH: 6.2-6.9) was sustained. Conversely, the synaptic recovery was potentiated when the acidosis was restored to the physiological milieu dur ing the reoxygenation period. These results suggest that acidosis plays a p rotective effect against the hypoxic neuronal damage only when rapid apprec iable pH recovery is achieved during reoxygenation. (C) 2000 Elsevier Scien ce B.V. All rights reserved.