| Reference code: | PT/FB/BL-2004-168.04 |
| Location: | Arquivo PCA - Pasta 13/2004
|
Title:
| Increased parahippocampal delta activity characterises virtual navigation and REM sleep in humans
|
| Publication year: | 2006
|
URL:
| http://fens2006.neurosciences.asso.fr/abstracts/R1/A018_3.html
|
| Abstract/Results: | ABSTRACT:
Hippocampal theta or rhythmic slow activity (RSA) occurring during exploratory behaviours and rapid-eye-movement (REM) sleep is a characteristic and salient oscillatory rhythm in animals. By contrast, much controversy exists regarding the existence and the characteristics of this activity in humans. Some studies argued that human hippocampal theta activity appears in short and phasic bursts. On the contrary, earlier we showed that REM-dependent RSA recorded from the parahippocampal region is continuous like in animals but instead of the theta it falls in the delta frequency range. Here, we examined parahippocampal activity in 10 epilepsy patients implanted with foramen ovale electrodes while they were engaged in a virtual navigation task. Navigation was tested according to three conditions: an acquisition, a recall and a non-learning route-following condition. Recordings were also sampled from resting and REM sleep. For analyses, spectral power densities (SPD) were calculated for each 1 Hz wide frequency bin up to 10 Hz. During acquisition, SPD significantly increased in the 1 Hz, 2 Hz and the 3 Hz frequency bins when compared with resting. A similar but more robust increase was present in the 1 Hz, 2 Hz, 3 Hz, 4 Hz and 5 Hz frequency bins during REM sleep. Thus, increase was present in similar frequencies during the two conditions and these frequency ranges were below the traditional theta band. At the same time, other features of this activity, such as state-dependency and tonicity made this activity comparable to that seen in animals and suggest this activity to be the human analogue hippocampal theta in animals.
|
| Accessibility: | Document does not exist in file
|
Language:
| eng
|
Author:
| Clemens, Z.
|
Secondary author(s):
| Borbély, C., Fabó, D., Halász, P.
|
Document type:
| Online abstract
|
Number of reproductions:
| 1
|
Reference:
| Clemens, Z., Borbély, C., Fabó, D., & Halász P. (2006). Increased parahippocampal delta activity characterises virtual navigation and REM sleep in humans. FENS Abstr., vol.3, A018.3, 2006. Abstract retrieved from http://fens2006.neurosciences.asso.fr/abstracts/R1/A018_3.html
|
| Indexed document: | No
|
| Keywords: | Parahippocampal activity / Epilepsy / Virtual navigation / Sleep / Learning
|
|