CORRELATION BETWEEN CORTICAL EEG AND STRIATAL MICRODIALYSIS IN SOMAN-INTOXICATED RATS

In vivo microdialysis and EEG recording have been used in order to stu dy the combined neurochemical and electrophysiological events during i ntoxication with soman (o-1,2,2-trimethylpropyl methylphosphono-fluori date), a potent inhibitor of acetylcholinesterase (AChE), in the freel y moving rat. All rats exposed to soman exhibited signs of AChE inhibi tion. The duration of EEG recorded seizures after soman intoxication a veraged 43 +/- 24 min. The extracellular striatal levels of dopamine a nd GABA, increased significantly during the EEG seizure periods. Using an EEG based differentiation between seizure and non-seizure conditio ns, we found that intrastriatal release of dopamine, but not glutamate , during soman intoxication is highly correlated with seizures. Our re sults suggest that excitatory amino acids (EAA) involvement in soman-i nduced seizures, as demonstrated in hippocampus, may not be relevant i n the striatum. Our data, instead, may indicate the importance of dopa mine as a neurotoxic agent. (C) 1997 Elsevier Science Ireland Ltd.