Cell-Damaging Conditions Release More Taurine than Excitatory Amino Acids from the Immature Hippocampus
High concentrations of excitatory amino acids are neurotoxic and overstimulation of their receptors contributes to neuronal death during cerebral ischemia35. Excitatory amino acids are released from neural structures from adult animals during hypoxia and ischemia1,7,20,23. Oxygen-derived free radicals formed in hypoxic brain tissue also induce release of excitatory amino acids22 and thus contribute to ischemia-induced neuronal damage4. Of the various brain areas, the hippocampus is particularly vulnerable to ischemic injury25. In the newborn, however, the hippocampus is relatively well spared after hypoxia and ischemia3,5. The major part of excitatory innervation in the hippocampus is glutamatergic. Taurine also abounds in the hippocampus11 and taurine-like immunore-activity has been located in hippocampal interneurons, pyramidal neurons and dentate granule cells15. This inhibitory amino acid seems to be essential for the development and survival of neural cells8,34. We have now assessed the simultaneous release of endogenous excitatory amino acids, glutamate and aspartate, together with taurine, in the above cell-damaging conditions in hippocampal slices prepared from immature mice.
KeywordsHippocampal Slice Excitatory Amino Acid Basal Release Inhibitory Amino Acid Taurine Release
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