Non-rapid eye movement sleep 3D maze. Participants were then trained in the maze for 4 hours and later, during the various sleep cycles of nonREM sleep, REM sleep and wakefulness, they were scanned twelve times using a PET scan during the night. The PET scan demonstrated a higher blood flow in the hippocampus during SWS/non-REM sleep due to the training from the previous day while the control group exhibited no increased blood flow and they had not received the training the prior day. The brain activity during sleep, according to this study, would show the events of the previous day do make a difference.
PGO waves and subthalamic nucleus (or subthalamus). This latter, glutamatergic nucleus is reciprocally connected with the PGO-transferring nuclei of the pons. In humans, subthalamic PGO-like waves, that resemble the PGO waves typically recorded in cats, can be recorded during pre-REM and REM sleep. This suggests that the subthalamus may play an active role in an ascending activating network implicated in the rostral transmission of PGO waves during REM sleep in humans. PGO waves are an integral part of rapid eye movement (REM) sleep. As stated earlier, the density of the PGO waves coincides with the amount of eye movement measured in REM