The analysis of quantitative EEG (EEG power spectra and EEG coherence) in three pharmacological models of psychosis (ketamine 9 and 30 mg/kg i.p., amphetamine 1 and 4 mg/kg i.p. and 2C-B 10 and 50 mg/kg s.c.) in freely moving rats was performed. To verify that drugs are behaviorally active at doses we used, we have also analyzed locomotor activity and prepulse inhibition (PPI) of acoustic startle reaction. Male Wistar rats, b.w 200 – 300g were used in all experiments. Locomotion was registered in the open field test (Ethovision) and measurement of PPI was performed in a SR-LAB startle chamber. For the EEG study, rats were stereo-tactically implanted with 14 silver electrodes (12 active). EEG was recorded using a 21-channel BrainScope amplifier system and analyzed with Neuroguide Deluxe software v. 2.3.7. All drugs produced behavioral changes, hyper or hypolocomotion and/or deficits in the PPI, and induced specific changes in EEG spectra. EEG coherences massively increased in the ketamine model, on the contrary in amphetamine only a few changes have been observed. 2C-B had biphasic effect with mainly predominant decrease in fronto-temporal coherence initially, followed by reversal of these effects. EEG coherence revealed an overall increase in cortical functional connectivity after ketamine, on the contrary only a few changes, mainly a decrease, in the connectivity in the amphetamine model. The initial decrease in fronto-temporal coherence after 2C-B is similar to what has been frequently described in schizophrenics.

This work is supported by projects MEYSCR 1M0517, MHCR NR-8785-3, MHCR MZ0PCP2005 and MHCR NR-8792-3.