[Changes in electroencephalograph and somatosensory evoked potential and their relationship with neuron apoptosis in rat after ischemic insult to brain].

Objective: To study the changes in electroencephalograph (EEG) and somatosensory evoked potential (SEP) and their relationship with neuron apoptosis in rat after ischemic insult to the brain.

Methods: Thirty-five SD rats were randomly divided into normal, sham operated and 3, 12, 24, 48, 72 hours after ischemia/reperfusion (I/R) groups with 5 rats in each group. The ischemia of brain was produced by clamping 4 vessels to the brain for various periods of time. Changes in EEG and SEP were recorded at different time after I/R, and the amounts of apoptotic neurons in hippocampus and cortex after I/R were assessed with terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL) and acridine orange ethidium bromide (AO/EB) fluorescence examination techniques.

Results: Compared with sham operated group, EEG amplitude decreased significantly (all P<0.05), and the proportion of Delta wave increased significantly after ischemia of the brain (all P<0.05). The latent period of P1 wave crest extended markedly (all P<0.05), and P1-N1 amplitude decreased significantly after I/R (all P<0.05). EEG and SEP changes were correlated with the apoptosis and loss of neurons, which started in the hippocampus and extended to frontal cortex and parietal cortex.

Conclusion: The combined analysis of EEG and SEP can reflect the process of neuron apoptosis, which is helpful for the diagnosis and evaluation of prognosis of patients suffering from cerebral ischemia.