<?xml version='1.0' encoding='UTF-8'?><xml><records><record><source-app name="HighWire" version="7.x">Drupal-HighWire</source-app><ref-type name="Journal Article">17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Zheng, Chenguang</style></author><author><style face="normal" font="default" size="100%">Wood Bieri, Kevin</style></author><author><style face="normal" font="default" size="100%">Hwaun, Ernie</style></author><author><style face="normal" font="default" size="100%">Lee Colgin, Laura</style></author></authors><secondary-authors></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Fast gamma rhythms in the hippocampus promote encoding of novel object-place pairings</style></title><secondary-title><style face="normal" font="default" size="100%">eneuro</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2016</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2016-04-29 00:00:00</style></date></pub-dates></dates><elocation-id><style  face="normal" font="default" size="100%">ENEURO.0001-16.2016</style></elocation-id><doi><style  face="normal" font="default" size="100%">10.1523/ENEURO.0001-16.2016</style></doi><volume><style face="normal" font="default" size="100%"></style></volume><issue><style face="normal" font="default" size="100%"></style></issue><abstract><style  face="normal" font="default" size="100%">Hippocampal gamma rhythms increase during mnemonic operations (Johnson and Redish, 2007; Montgomery and Buzsaki, 2007; Sederberg et al., 2007; Jutras et al., 2009; Trimper et al., 2014) and may affect memory encoding by coordinating activity of neurons that code related information (Jensen and Lisman, 2005). Here, a hippocampal-dependent, object-place association task (Clark et al., 2000; Broadbent et al., 2004; Eacott and Norman, 2004; Lee et al., 2005; Winters et al., 2008; Barker and Warburton, 2011) was used in rats to investigate how slow and fast gamma rhythms in the hippocampus relate to encoding of memories for novel object-place associations. In novel object tasks, the degree of hippocampal dependence has been reported to vary depending on the type of novelty (Eichenbaum et al., 2007; Winters et al., 2008). Therefore, gamma activity was examined during three novelty conditions: a novel object presented in a location where a familiar object had been (NO), a familiar object presented in a location where no object had been (NL), and a novel object presented in a location where no object had been (NO+NL). The strongest and most consistent effects were observed for fast gamma rhythms during the NO+NL condition. Fast gamma power, CA3-CA1 phase synchrony, and phase-locking of place cell spikes increased during exploration of novel, compared to familiar, object-place associations. Additionally, place cell spiking during exploration of novel object-place pairings was increased when fast gamma rhythms were present. These results suggest that fast gamma rhythms promote encoding of memories for novel object-place associations.Significance Statement: This study provides the first evidence that links fast gamma rhythms in the hippocampus to encoding of novel object-place associations in a behavioral task. The results also relate these effects to firing patterns in place cells that resemble stimulation patterns that are routinely used to induce long-term potentiation, the presumed synaptic substrate of memory formation.</style></abstract></record></records></xml>