Selective rapid eye movement sleep deprivation impairs the maintenance of long-term potentiation in the rat hippocampus

Rapid eye movement (REM) sleep deprivation (RSD) is known to impair learning and memory. Previous studies have demonstrated that RSD induces an impairment of hippocampal long-term potentiation (LTP). In most of these studies, RSD was set up prior to LTP induction. In this work, we focused on RSD after LTP induction. We investigated the effect of RSD for 24-48 h after induction of LTP in the dentate gyrus on LTP maintenance and whether a REM rebound after 48 h RSD affected LTP. RSD rats were deprived of REM sleep by stroking their backs using a brush, whereas control rats were allowed to sleep freely. Another control group of rats was awoken during non-REM sleep (NRS) under the same conditions (NRS group). REM-deprived rats displayed a faster decay of population spike amplitudes compared with the control and NRS groups over a 24-h recording time. After 48 h RSD, there was no difference in the population spike amplitudes before or after 4 h of release from RSD. These results suggest that REM sleep after LTP induction in the dentate gyrus plays an essential role in LTP maintenance, whereas a REM rebound does not restore the RSD-induced impairment of LTP.