title: Firing rates of hippocampal neurons are preserved during subsequent sleep episodes and modified by novel awake experience.
abstract: What determines the firing rate of cortical neurons in the absence of external sensory input or motor behavior, such as during sleep? Here we report that, in a familiar environment, the discharge frequency of simultaneously recorded individual CA1 pyramidal neurons and the coactivation of cell pairs remain highly correlated across sleep-wake-sleep sequences. However, both measures were affected when new sets of neurons were activated in a novel environment. Nevertheless, the grand mean firing rate of the whole pyramidal cell population remained constant across behavioral states and testing conditions. The findings suggest that long-term firing patterns of single cells can be modified by experience. We hypothesize that increased firing rates of recently used neurons are associated with a concomitant decrease in the discharge activity of the remaining population, leaving the mean excitability of the hippocampal network unaltered.
authors.affiliation: Center for Molecular and Behavioral Neuroscience, Rutgers, State University of New Jersey, 197 University Avenue, Newark, NJ 07102, USA.
authors.forename: H
authors.initials: H
authors.lastname: Hirase
authors.forename: X
authors.initials: X
authors.lastname: Leinekugel
authors.forename: A
authors.initials: A
authors.lastname: Czurkó
authors.forename: J
authors.initials: J
authors.lastname: Csicsvari
authors.forename: G
authors.initials: G
authors.lastname: Buzsáki
mesh_terms: D000818:Animals; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*