Abstract
The changes in EEG and EP were investigated on the rat and the rabbit, in relation to the SP shift produced by DC application and repetitive brainstem stimulation.
1. EEG and EP changed correlatively very often, if not always, with the forced SP-shift generated by DC application.
2. In general, the cortical surface, in resting state, showed a slight positive steady potential relative to indifferent electrode placed on the nasal area. Therefore the application of slight negative DC was observed to supersede this positive steady potential. EP changed not only in amplitude, but also in polarity associated with the forced SP-shift, namely in positive direction by negative SP level and in negative direction by positive SP level.
3. The slow component in EEG and EP changed (mainly in amplitude) in many cases in proportion to the magnitude of SP-shift.
4. Repetitive stimulation of lower reticular formation caused sometimes the changes in SP, EEG and EP. However, there could not be found any consistent and regular correlation between them.
5. RF stimulation of very low frequency caused the arousal reaction in EEG, when it was very low or very high in intensity. When the stimulation was moderate in intensity, the arousal reaction could not be produced by lower frequency. However, with increase in intensity, even very low frequency showed the significant arousal effect on EEG.
