title: Feedback modulation of neural network synchrony and seizure susceptibility by Mdm2-p53-Nedd4-2 signaling.
abstract: BACKGROUND
  Neural network synchrony is a critical factor in regulating information transmission through the nervous system. Improperly regulated neural network synchrony is implicated in pathophysiological conditions such as epilepsy. Despite the awareness of its importance, the molecular signaling underlying the regulation of neural network synchrony, especially after stimulation, remains largely unknown.
  
  
  RESULTS
  In this study, we show that elevation of neuronal activity by the GABA(A) receptor antagonist, Picrotoxin, increases neural network synchrony in primary mouse cortical neuron cultures. The elevation of neuronal activity triggers Mdm2-dependent degradation of the tumor suppressor p53. We show here that blocking the degradation of p53 further enhances Picrotoxin-induced neural network synchrony, while promoting the inhibition of p53 with a p53 inhibitor reduces Picrotoxin-induced neural network synchrony. These data suggest that Mdm2-p53 signaling mediates a feedback mechanism to fine-tune neural network synchrony after activity stimulation. Furthermore, genetically reducing the expression of a direct target gene of p53, Nedd4-2, elevates neural network synchrony basally and occludes the effect of Picrotoxin. Finally, using a kainic acid-induced seizure model in mice, we show that alterations of Mdm2-p53-Nedd4-2 signaling affect seizure susceptibility.
  
  
  CONCLUSIONS
  Together, our findings elucidate a critical role of Mdm2-p53-Nedd4-2 signaling underlying the regulation of neural network synchrony and seizure susceptibility and reveal potential therapeutic targets for hyperexcitability-associated neurological disorders.
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Jewett
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.|Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Christian
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Bacos
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Kwan Young
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Jiuhe
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Molecular and Integrative Physiology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. nptsai@illinois.edu.|Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA. nptsai@illinois.edu.
authors.forename: Nien-Pei
authors.initials: NP
authors.lastname: Tsai
mesh_terms: D000818:Animals; D004198:Disease Susceptibility; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism*; D025461:Feedback, Physiological; D008297:Male; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D000075702:Nedd4 Ubiquitin Protein Ligases; D009415:Nerve Net / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism*; D012640:Seizures / Q000378:metabolism* / Q000473:pathology*; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D016159:Tumor Suppressor Protein p53; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618461:Nedd4l protein, mouse; C497207:Mdm2 protein, mouse; D051736:Proto-Oncogene Proteins c-mdm2; D044767:Ubiquitin-Protein Ligases
keywords: Mdm2; Multielectrode array; Nedd4-2; Network activity; Seizure; Synchrony; p53