title: Sleep-wakefulness cycle and behavior in pannexin1 knockout mice.
abstract: Pannexins are membrane channel proteins that play a role in a number of critical biological processes (Panchin et al., 2000; Shestopalov, Panchin, 2008). Among other cellular functions, pannexin hemichannels serve as purine nucleoside conduits providing ATP efflux into the extracellular space (Dahl, 2015), where it is rapidly degraded to adenosine. Pannexin1 (Panx1) is abundantly expressed in the brain and has been shown to contribute to adenosine signaling in nervous system tissues (Prochnow et al., 2012). We hypothesized that pannexin1 may contribute to sleep-wake cycle regulation through extracellular adenosine, a well-established paracrine factor in slow wave sleep. To investigate this link, EEG and movement activity throughout the light/dark cycle were compared in Panx1-/-and Panx1+/+mice. We found a significant increase in waking and a correspondent decrease in slow wave sleep percentages in the Panx1-/-animals. These changes were especially pronounced during the dark period. Furthermore, we found a significant increase in movement activity of Panx1-/-mice. These findings are consistent with the hypothesis that extracellular adenosine is relatively depleted in Panx1-/-animals due to the absence of the ATP-permeable hemichannels. At the same time, sleep rebound after a 6-h sleep deprivation remained unchanged in Panx1-/-mice as compared to the control animals. Behavioral tests revealed that Panx1-/-mice were significantly faster during their descent along the vertical pole but more sluggish during their run through the horizontal pole as compared to the control mice.
authors: Severtsov Institute Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: V M
authors: VM
authors: Kovalzon
authors: Severtsov Institute Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: L S
authors: LS
authors: Moiseenko
authors: Severtsov Institute Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
authors: A V
authors: AV
authors: Ambaryan
authors: Bascom Palmer Eye Institute, University of Miami School Medicine, Miami, Florida, USA.
authors: S
authors: S
authors: Kurtenbach
authors: Bascom Palmer Eye Institute, University of Miami School Medicine, Miami, Florida, USA; Vavilov Institute for General Genetics, Russian Academy of Sciences, Moscow, Russia.
authors: V I
authors: VI
authors: Shestopalov
authors: Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia; Belozersky Institute for Physicochemical Biology, Lomonosov Moscow State University, Moscow, Russia. Electronic address: ypanchin@yahoo.com.
authors: Y V
authors: YV
authors: Panchin
mesh_terms: D000818:Animals; D017630:Connexins / Q000235:genetics / Q000502:physiology*; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D017440:Photoperiod; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
chemical_list: D017630:Connexins; D009419:Nerve Tissue Proteins; C503631:Panx1 protein, mouse
keywords: ATP; Adenosine; Gene knockout models; Hemichannels; Pannexin; Purinergic signaling; Sleep