title: Firing rate homeostasis in visual cortex of freely behaving rodents.
abstract: It has been postulated that homeostatic mechanisms maintain stable circuit function by keeping neuronal firing within a set point range, but such firing rate homeostasis has never been demonstrated in vivo. Here we use chronic multielectrode recordings to monitor firing rates in visual cortex of freely behaving rats during chronic monocular visual deprivation (MD). Firing rates in V1 were suppressed over the first 2 day of MD but then rebounded to baseline over the next 2-3 days despite continued MD. This drop and rebound in firing was accompanied by bidirectional changes in mEPSC amplitude measured ex vivo. The rebound in firing was independent of sleep-wake state but was cell type specific, as putative FS and regular spiking neurons responded to MD with different time courses. These data establish that homeostatic mechanisms within the intact CNS act to stabilize neuronal firing rates in the face of sustained sensory perturbations.
authors.affiliation: Department of Biology, Brandeis University, Waltham, MA 02454, USA.
authors.forename: Keith B
authors.initials: KB
authors.lastname: Hengen
authors.forename: Mary E
authors.initials: ME
authors.lastname: Lambo
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Van Hooser
authors.forename: Donald B
authors.initials: DB
authors.lastname: Katz
authors.forename: Gina G
authors.initials: GG
authors.lastname: Turrigiano
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D008297:Male; D055369:Miniature Postsynaptic Potentials / Q000502:physiology; D018670:Monitoring, Ambulatory / Q000379:methods; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D051381:Rats; D012683:Sensory Deprivation / Q000502:physiology*; D012890:Sleep / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology