Comparative analysis of the neurophysiological profile of group II metabotropic glutamate receptor activators and diazepam: Effects on hippocampal and cortical EEG patterns in rats

► Hippocampal theta is modulated similarly by diazepam and mGlu2/3 activators. ► mGlu2/3 receptor activators decrease the frequency of stimulated theta in rats. ► In freely moving rats mGlu2/3 activation decreases REM sleep. ► mGlu2/3 activators elicit EEG changes in freely moving rats opposite to diazepam.