[The participation of the 5-HT1 and 5-HT2 subtypes of the serotonin receptors in the formation of the frequency component in the EEG of non-narcotized rats].

Experiments were conducted on 6 non-narcotized and non-immobilized rats with chronically implanted electrodes in the somatosensory area of the brain cortex and a cannula in the lateral cerebral ventricle to detect the dose-dependent EEG spectra changes after intracerebral injection of quipasin, agonist of 5-HT1--5-HT2-subtype serotonin receptors. The changes were displayed in a significant increase of the rhythms in the subranges 1.5; 4-6; 20-30 Hz and weakening of rhythms in 7-16 Hz in comparison to the corresponding parameters in control experiments with physiological solution. Preliminary injection of cyproheptadine (antagonist of 5-HT1--5-HT2 receptors) weakened significantly the EEG-effects of quipasin. Buspirone and ritanserine (agonist and antagonist of 5-HT1 receptors) induced EEG changes similar to the effects of cyprohetadine and quipasin, respectively. The possible mechanisms of the participation of various subtypes of serotonin receptors in the observed EEG effects are discussed.