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Beta2 oscillations (23–30 Hz) in the mouse hippocampus during novel object recognition
Author(s) -
França Arthur S. C.,
Nascimento George C.,
LopesdosSantos Vítor,
Muratori Larissa,
Ribeiro Sidarta,
LobãoSoares Bruno,
Tort Adriano B. L.
Publication year - 2014
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12739
Subject(s) - hippocampal formation , local field potential , neuroscience , hippocampus , novelty , memory consolidation , session (web analytics) , psychology , computer science , social psychology , world wide web
The oscillatory activity of hippocampal neuronal networks is believed to play a role in memory acquisition and consolidation. Particular focus has been given to characterising theta (4–12 Hz), gamma (40–100 Hz) and ripple (150–250 Hz) oscillations. Beyond these well‐described network states, few studies have investigated hippocampal beta2 (23–30 Hz) activity in vivo and its link to behaviour. A previous sudy showed that the exploration of novel environments may lead to the appearance of beta2 oscillations in the mouse hippocampus. In the present study we characterised hippocampal beta2 oscillations in mice during an object recognition task. We found prominent bursts of beta2 oscillations in the beginning of novel exploration sessions (four new objects), which could be readily observed by spectral analysis and visual inspection of local field potentials. Beta2 modulated hippocampal but not neocortical neurons and its power decreased along the session. We also found increased beta2 power in the beginning of a second exploration session performed 24 h later in a slightly modified environment (two new, two familiar objects), but to a lesser extent than in the first session. However, the increase in beta2 power in the second exploration session became similar to the first session when we pharmacologically impaired object recognition in a new set of experiments performed 1 week later. Our results suggest that hippocampal beta2 activity is associated with a dynamic network state tuned for novelty detection and which may allow new learning to occur.