title: REM sleep reorganizes hippocampal excitability.
abstract: Sleep is composed of an alternating sequence of REM and non-REM episodes, but their respective roles are not known. We found that the overall firing rates of hippocampal CA1 neurons decreased across sleep concurrent with an increase in the recruitment of neuronal spiking to brief "ripple" episodes, resulting in a net increase in neural synchrony. Unexpectedly, within non-REM episodes, overall firing rates gradually increased together with a decrease in the recruitment of spiking to ripples. The rate increase within non-REM episodes was counteracted by a larger and more rapid decrease of discharge frequency within the interleaved REM episodes. Both the decrease in firing rates and the increase in synchrony during the course of sleep were correlated with the power of theta activity during REM episodes. These findings assign a prominent role of REM sleep in sleep-related neuronal plasticity.
authors.affiliation: Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, 197 University Avenue, Newark, NJ 07102, USA.
authors.forename: Andres D
authors.initials: AD
authors.lastname: Grosmark
authors.forename: Kenji
authors.initials: K
authors.lastname: Mizuseki
authors.forename: Eva
authors.initials: E
authors.lastname: Pastalkova
authors.forename: Kamran
authors.initials: K
authors.lastname: Diba
authors.forename: György
authors.initials: G
authors.lastname: Buzsáki
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology* / Q000502:physiology; D004558:Electric Stimulation; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology*; D013057:Spectrum Analysis; D013826:Theta Rhythm / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness