article
Theta-associated high-frequency oscillations (110–160 Hz) in the hippocampus and neocortex
Fecha
2013Registro en:
TORT, A. B. L. ; SCHEFFER-TEIXEIRA, R ; Souza, B.C. ; DRAGUHN, A. ; BRANKACK, J. (2013)
Autor
Tort, Adriano Bretanha Lopes
Scheffer-Teixeira, Robson
Souza, Bryan C.
Draguhn, Andreas
Brankacˇk, Jurij
Resumen
We review recent evidence for a novel type of fast cortical oscillatory activity that occurs circumscribed
between 110 and 160 Hz, which we refer to as high-frequency oscillations (HFOs). HFOs characteristically
occur modulated by theta phase in the hippocampus and neocortex. HFOs can co-occur with
gamma oscillations nested in the same theta cycle, in which case they typically peak at different theta
phases. Despite the overlapping frequency ranges, HFOs differ from hippocampal ripple oscillations in
some key characteristics, including amplitude, region of occurrence, associated behavioral state, and
activity time-course (sustained vs intermittent). Recent in vitro evidence suggests that HFOs depend on
fast GABAergic transmission and may also depend on axonal gap junctions. The functional role of HFOs is
currently unclear. Both hippocampal and neocortical theta-HFO coupling increase during REM sleep,
suggesting a role for HFOs in memory processing