Phase-locking of spontaneous and tone-elicited pontine waves to hippocampal theta waves during REM sleep in rats.
Temporal relationships between hippocampal theta waves and pontine waves (P waves) during rapid-eye-movement (REM) sleep were investigated in rats. P waves were phase-locked to the positive theta peak. The phase relationships of P waves elicited by a tone stimulus (P(E) waves) to hippocampal theta waves were also analyzed to qualitatively clarify the mechanism of phase-locking between these two phenomena. P(E) waves occurred at the positive theta peak, as seen for spontaneous P waves. This phase preference of P(E) waves could be understood as that of the response probability to tone stimulus. These data suggest that the P-wave generator receives inputs that mimic theta waves. As hippocampal theta waves and P waves are known to be involved in learning and memory processes during REM sleep, the present studies could help to clarify these functions.
Karashima
Akihiro
A
Laboratory of Biomodeling, Graduate School of Information Sciences, Tohoku University, Aoba-yama 6-3-09, Aramaki, Sendai 980-8579, Japan. karasima@biomdl.ecei.tohoku.ac.jp
Katayama
Norihiro
N
Nakao
Mitsuyuki
M
D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D006624:Hippocampus / Q000502:physiology*; D008954:Models, Biological; D011149:Pons / Q000502:physiology*; D011336:Probability; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D012895:Sleep, REM / Q000502:physiology*; D013826:Theta Rhythm / Q000528:radiation effects