SLEEP AND PSYCHEDELIC STATES IN THE RAT BRAIN: BEHAVIORAL, ELECTROPHYSIOLOGICAL AND MOLECULAR STUDIES
5-MeO-DMT, NN-DLS, serotonergic agonists, hippocampus, prefrontal cortex, theta rhythm, phase-amplitude modulation, rat, sleep, proteomics
Psychedelics or classic hallucinogens are substances known for altering consciousness. Early experiments on several hallucinogens demonstrated that this effect is dependent on 5-HT2A and 1A serotonergic receptors, but due to the long prohibition of the recreational and research use of these drugs little is known about their electrophysiological effects on the brain. In the current work, we investigate the effects of 5-MeO-DMT and NN-DLS, two strong serotonergic agonists, on the hippocampus and prefrontal cortex of rats. We found typical behavioural alterations following ~15 min after drug injection such as increased locomotion and arena occupancy and stereotyped behaviours (wetdog shake, uncoordinated walking). Similar to previous results, we found alterations in the local field potentials in prefrontal areas (PF), as well as in the hippocampus (HP). While the power in the low gamma band (20-50 Hz) decreased in the two areas in the first 30 min, delta (0-5 Hz) band showed an increase in PF and a mixed dynamic in HP, with a delayed increase. At last, theta (5-10 Hz) power showed a tendency to decrease in HP. We also found that hippocampal-cortical LFP synchrony can be altered in the time course following injection, showing increased coherence in the theta band despite its lower power levels in the HP. While some of those results corroborate with previous literature (e.g., the decrease in gamma power in PF), we also found divergent ones, such as the increase in PF delta power. Additionally, we also describe novel results that promote a better understanding of the electrophysiological alterations caused by classic hallucinogens in the brain.