AUTHOR=Peyrache Adrien , Benchenane Karim , Khamassi Mehdi , Wiener Sidney I., Battaglia Francesco P.
TITLE=Sequential reinstatement of neocortical activity during slow oscillations depends on cells' global activity
JOURNAL=Frontiers in Systems Neuroscience
VOLUME=Volume 3 - 2009
YEAR=2010
URL=https://www.frontiersin.org/journals/systems-neuroscience/articles/10.3389/neuro.06.018.2009
DOI=10.3389/neuro.06.018.2009
ISSN=1662-5137
ABSTRACT=During Slow Wave Sleep (SWS), cortical activity is dominated by endogenous processes modulated by slow oscillations (0.1-1 Hz): cell ensembles fluctuate between states of sustained activity (UP states) and silent epochs (DOWN states). We investigate here the temporal structure of ensemble activity during UP states by means of multiple single unit recordings in the prefrontal cortex of naturally sleeping rats. As previously shown, the firing rate of each PFC cell peaks at a distinct time lag after the DOWN/UP transition in a consistent order. We show here that, conversely, the latency of the first spike after the UP state onset depends primarily on the session-averaged firing rates of cells (which can be considered as an indirect measure of their intrinsic excitability). This latency can be explained by a simple homogeneous process (Poisson model) of cell firing, with sleep averaged firing rates employed as parameters. Thus, at DOWN/UP transitions, neurons are affected both by a slow process, possibly originating in the cortical network, modulating the time course of firing for each cell, and by a fast, relatively stereotyped reinstatement of activity, related mostly to global activity levels.