Instantaneous acceleration and amplification of hippocampal theta wave coincident with phasic pontine activities during REM sleep.
Rapid eye movement (REM) sleep is characterized by hippocampal theta waves and phasic spike-like waves originating from the pons, termed ponto-geniculo-occipital (PGO) waves in cats and pontine (P) waves in rats. While the theta wave and PGO/P wave have been suggested to participate in higher-order brain functions, their generation mechanisms and roles in brain functions have been studied independently. Therefore, the present study investigated instantaneous aspects of the relationship between theta waves and PGO/P waves in both cats and rats. Theta wave was instantaneously accelerated several hundred milliseconds before the negative peak of the PGO/P wave in both animals, and was also amplified just before PGO/P wave occurrence. Considering the integrated knowledge provided by studies of both animals, these results suggest that PGO/P wave-related activities in the pons are delivered to the theta wave generator. The activations of the theta wave coincident with PGO/P wave might facilitate cooperative contribution to higher-order brain functions in REM sleep.
Laboratory of Biomodeling, Graduate School of Information Sciences, Tohoku University, Aza Aoba 6-3-09, Aramaki, Aoba-ku, Sendai 980-8579, Japan. karashima@biomdl.ecei.tohoku.ac.jp
Akihiro
A
Karashima
Mitsuyuki
M
Nakao
Norihiro
N
Katayama
Kazuki
K
Honda
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002415:Cats; D005829:Geniculate Bodies / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology*; D011149:Pons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012895:Sleep, REM / Q000502:physiology*; D013826:Theta Rhythm