Principal component analysis of ensemble recordings reveals cell assemblies at high temporal resolution.
Simultaneous recordings of many single neurons reveals unique insights into network processing spanning the timescale from single spikes to global oscillations. Neurons dynamically self-organize in subgroups of coactivated elements referred to as cell assemblies. Furthermore, these cell assemblies are reactivated, or replayed, preferentially during subsequent rest or sleep episodes, a proposed mechanism for memory trace consolidation. Here we employ Principal Component Analysis to isolate such patterns of neural activity. In addition, a measure is developed to quantify the similarity of instantaneous activity with a template pattern, and we derive theoretical distributions for the null hypothesis of no correlation between spike trains, allowing one to evaluate the statistical significance of instantaneous coactivations. Hence, when applied in an epoch different from the one where the patterns were identified, (e.g. subsequent sleep) this measure allows to identify times and intensities of reactivation. The distribution of this measure provides information on the dynamics of reactivation events: in sleep these occur as transients rather than as a continuous process.
Peyrache
Adrien
A
Laboratoire de Physiologie de la Perception et de l'Action, Collège de France, CNRS, 11, place Marcelin Berthelot, 75231, Paris Cedex 05, France. adrien.peyrache@college-de-france.fr.
Benchenane
Karim
K
Laboratoire de Physiologie de la Perception et de l'Action, Collège de France, CNRS, 11, place Marcelin Berthelot, 75231, Paris Cedex 05, France.
Khamassi
Mehdi
M
Laboratoire de Physiologie de la Perception et de l'Action, Collège de France, CNRS, 11, place Marcelin Berthelot, 75231, Paris Cedex 05, France.|Institut des Systèmes Intelligents et de Robotique, Université Pierre et Marie Curie - Paris 6, CNRS FRE 2507, 4 Place Jussieu, 75252, Paris Cedex, France.
Wiener
Sidney I
SI
Laboratoire de Physiologie de la Perception et de l'Action, Collège de France, CNRS, 11, place Marcelin Berthelot, 75231, Paris Cedex 05, France.
Battaglia
Francesco P
FP
Laboratoire de Physiologie de la Perception et de l'Action, Collège de France, CNRS, 11, place Marcelin Berthelot, 75231, Paris Cedex 05, France.|Center for Neuroscience, Swammerdam Institute for Life Sciences, Faculty of Science, Universiteit van Amsterdam, P.O. Box 94084, Kruislaan 320, 1090GB, Amsterdam, The Netherlands.
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D025341:Principal Component Analysis; D011336:Probability; D012890:Sleep / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology