title: An embedded subnetwork of highly active neurons in the neocortex.
abstract: Unbiased methods to assess the firing activity of individual neurons in the neocortex have revealed that a large proportion of cells fire at extremely low rates (<0.1 Hz), both in their spontaneous and evoked activity. Thus, firing in neocortical networks appears to be dominated by a small population of highly active neurons. Here, we use a fosGFP transgenic mouse to examine the properties of cells with a recent history of elevated activity. FosGFP-expressing layer 2/3 pyramidal cells fired at higher rates compared to fosGFP(-) neurons, both in vivo and in vitro. Elevated activity could be attributed to increased excitatory and decreased inhibitory drive to fosGFP(+) neurons. Paired-cell recordings indicated that fosGFP(+) neurons had a greater likelihood of being connected to each other. These findings indicate that highly active, interconnected neuronal ensembles are present in the neocortex and suggest these cells may play a role in the encoding of sensory information.
authors.affiliation: Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA.
authors.forename: Lina
authors.initials: L
authors.lastname: Yassin
authors.forename: Brett L
authors.initials: BL
authors.lastname: Benedetti
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Jouhanneau
authors.forename: Jing A
authors.initials: JA
authors.lastname: Wen
authors.forename: James F A
authors.initials: JF
authors.lastname: Poulet
authors.forename: Alison L
authors.initials: AL
authors.lastname: Barth
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D019579:Neocortex / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*