Volume 16 Supplement 1
Understanding short-timescale neuronal firing sequences via bias matrices
© Roth et al. 2015
Published: 18 December 2015
The brain generates persistent neuronal firing sequences across varying timescales. The short-timescale (~100ms) sequences are believed to be crucial in the formation and transfer of memories. Large-amplitude local field potentials known as sharp-wave ripples (SWRs) occur irregularly in hippocampus when an animal has minimal interaction with its environment, such as during resting, immobility, or slow-wave sleep. SWRs have been long hypothesized to play a critical role in transferring memories from the hippocampus to the neocortex . While sequential firing during SWRs is known to be biased by the previous experiences of the animal, the exact relationship of the short-timescale sequences during SWRs and longer-timescale sequences during spatial and non-spatial behaviors is still poorly understood. One hypothesis is that the sequences during SWRs are "replays" or "preplays" of "master sequences", which are sequences that closely mimic the order of place fields on a linear track [2, 3]. Rather than particular hard-coded "master" sequences, an alternative explanation of the observed correlations is that similar sequences arise naturally from the intrinsic biases of firing between pairs of cells. To distinguish these and other possibilities, one needs mathematical tools beyond the center-of-mass sequences and Spearman's rank-correlation coefficient that are currently used.
- Girardeau G, Benchenane K, Wiener SI, Buzsáki G, Zugaro MB: Selective suppression of hippocampal ripples impairs spatial memory. Nat Neurosci. 2009, 12 (10): 1222-1223.PubMedView ArticleGoogle Scholar
- Diba K, Buzsáki G: Forward and reverse hippocampal place-cell sequences during ripples. Nat Neurosci. 2007, 10 (10): 1241-1242.PubMedPubMed CentralView ArticleGoogle Scholar
- Dragoi G, Tonegawa S: Preplay of future place cell sequences by hippocampal cellular assemblies. Nature. 2011, 469 (7330): 397-401.PubMedPubMed CentralView ArticleGoogle Scholar
- Wang Y, Romani S, Lustig B, Leonardo A, Pastalkova E: Theta sequences are essential for internally generated hippocampal firing fields. Nat Neurosci. 2015, 18 (2): 282-288.PubMedView ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.