Experimental Rats Induced Eeg And Epileptic Eeg Study

Electroencephalogram (EEG) is the intracranial or cortex potential change formed by cerebral neurons'electrical activities. Without any stimulation, the potential change recorded on the cortex or scalp by unipolar or bipolar electrode is named electroencephalogram (EEG). Correspondingly, a sort of specific cerebral electrical signals caused by some stimulation is named evoked potentials (EPs). With the development of signal processing and computer technologies, EEG signal processing has been developed rapidly.Clinical data recorded on human scalp can hardly reflect the electrical activity of cerebral neurons accurately. However, in the animal experiments, we can record intracranial EEG signal, which has high spatial resolution but few interference; they can reflect the electrical activities deep in the brain. So, we establish animal model for EEG record and analysis. In this paper, our research is focused on EPs from somatosensory evoked potential rat model and electrocorticogram (ECoG) and electrohippocampogram (EHG) from epilietiform discharges rat model. EEG is widely studied in psychophysiology, where EPs analysis is a vital part. To explain the form of EPs, we establish somatosensory evoked potential rat model and analyze the relationship between signals before and after the electric stimulation. The result shows, post-stimuli amplitudes are related with stimulation signals'amplitude rather than pre-stimuli amplitudes. According to experiments, as the amplitudes of stimulation signals increase, that of post-stimuli will grow synchronously. Pre-stimulus phase angle and post-stimuli latencies are inversely related, and partial phase resetting is clearly revealed. By using the method of outlying cases test in linear regression, we can quantitatively analyze the degree of phase resetting. The results demonstrate that there is partial phase resetting from pre- to post-stimuli signal.We also notice epileptic discharges EEG evoked by brain's injury of structure or lack of function, which has especial figure. We study epileptic and non-epileptic EEG signals from Pilocarpine-induced epileptic rat's ECoG and EHG by bispectrum analysis method. The results show that the bispectrum analysis is sensitive to the epileptic and non-epileptic EEG. The peak value of the bispectrum of normal EEG appears near the coordinate (0, 0), while the bispectrum apexes of the continual epileptiform discharges EEG appear in the high-frequency of the bi-frequency area.