[Hypoxic preconditioning enhances hypoxic tolerance of hippocampal neurons and synaptic function of rat].

Hypoxic preconditioning with different simulated altitudes (3,000 m and 5,000 m) was performed on Wistar rats and the evoked population spikes were recorded from the hippocampal slices of these rats. The results showed that the appearance of hypoxic injury potential (HIP) and the disappearance of presynaptic volley (PV) were significantly delayed in response to acute lethal hypoxia. HIP and PV delay became more apparent when the hypoxic preconditioning altitude was increased from 3,000 m to 5,000 m. After reoxygenation, the recovery rate of PV in hypoxic preconditioning groups at 3,000 m and 5,000 m was apparently higher than that of control. The above results suggest that hypoxic preconditioning of animals in vivo increases hypoxic tolerance of hippocampal neurons.