Display options
Share it on

Front Physiol. 2014 May 07;5:172. doi: 10.3389/fphys.2014.00172. eCollection 2014.

Roles of gap junctions, connexins, and pannexins in epilepsy.

Frontiers in physiology

Shanthini Mylvaganam, Meera Ramani, Michal Krawczyk, Peter L Carlen

Affiliations

  1. Neurobiology, Toronto Western Research Institute, University Health Network and University of Toronto Toronto, ON, Canada.

PMID: 24847276 PMCID: PMC4019879 DOI: 10.3389/fphys.2014.00172

Abstract

Enhanced gap junctional communication (GJC) between neurons is considered a major factor underlying the neuronal synchrony driving seizure activity. In addition, the hippocampal sharp wave ripple complexes, associated with learning and seizures, are diminished by GJC blocking agents. Although gap junctional blocking drugs inhibit experimental seizures, they all have other non-specific actions. Besides interneuronal GJC between dendrites, inter-axonal and inter-glial GJC is also considered important for seizure generation. Interestingly, in most studies of cerebral tissue from animal seizure models and from human patients with epilepsy, there is up-regulation of glial, but not neuronal gap junctional mRNA and protein. Significant changes in the expression and post-translational modification of the astrocytic connexin Cx43, and Panx1 were observed in an in vitro Co(++) seizure model, further supporting a role for glia in seizure-genesis, although the reasons for this remain unclear. Further suggesting an involvement of astrocytic GJC in epilepsy, is the fact that the expression of astrocytic Cx mRNAs (Cxs 30 and 43) is several fold higher than that of neuronal Cx mRNAs (Cxs 36 and 45), and the number of glial cells outnumber neuronal cells in mammalian hippocampal and cortical tissue. Pannexin expression is also increased in both animal and human epileptic tissues. Specific Cx43 mimetic peptides, Gap 27 and SLS, inhibit the docking of astrocytic connexin Cx43 proteins from forming intercellular gap junctions (GJs), diminishing spontaneous seizures. Besides GJs, Cx membrane hemichannels in glia and Panx membrane channels in neurons and glia are also inhibited by traditional gap junctional pharmacological blockers. Although there is no doubt that connexin-based GJs and hemichannels, and pannexin-based membrane channels are related to epilepsy, the specific details of how they are involved and how we can modulate their function for therapeutic purposes remain to be elucidated.

Keywords: animal models; connexins; epilepsy; gap junctions; glia; human cerebral tissue; neurons; pannexins

References

  1. Am J Physiol Cell Physiol. 2008 Sep;295(3):C752-60 - PubMed
  2. Proc Natl Acad Sci U S A. 2007 May 15;104(20):8322-7 - PubMed
  3. FEBS Lett. 2014 Apr 17;588(8):1379-88 - PubMed
  4. Epilepsia. 2000;41 Suppl 6:S185-9 - PubMed
  5. Neuroscience. 2001;105(3):589-98 - PubMed
  6. J Med Genet. 2004 Jul;41(7):e93 - PubMed
  7. Iran Biomed J. 2012;16(1):25-32 - PubMed
  8. Mol Med Rep. 2008 Sep-Oct;1(5):721-7 - PubMed
  9. Ann N Y Acad Sci. 1986;481:72-86 - PubMed
  10. J Neurosci. 2006 May 17;26(20):5438-47 - PubMed
  11. J Physiol. 1993 Sep;469:639-52 - PubMed
  12. Brain Res Brain Res Rev. 2004 Dec;47(1-3):216-26 - PubMed
  13. Trends Cell Biol. 2010 Feb;20(2):92-101 - PubMed
  14. Cell Commun Adhes. 2009 Dec;16(5-6):131-7 - PubMed
  15. Science. 2008 Dec 5;322(5907):1555-9 - PubMed
  16. Brain Res. 2012 Dec 3;1487:107-22 - PubMed
  17. Neurosci Bull. 2011 Dec;27(6):389-406 - PubMed
  18. Eur J Neurosci. 2000 Jun;12(6):2087-96 - PubMed
  19. Neurotherapeutics. 2010 Oct;7(4):424-38 - PubMed
  20. J Neurosurg. 2006 Jul;105(1):77-87 - PubMed
  21. Mol Biol Cell. 2005 Jul;16(7):3100-6 - PubMed
  22. J Physiol. 2003 Aug 1;550(Pt 3):873-87 - PubMed
  23. Mol Pharmacol. 2003 Jun;63(6):1389-97 - PubMed
  24. Nature. 2012 May 27;486(7403):410-4 - PubMed
  25. Proc Natl Acad Sci U S A. 2007 Jul 24;104(30):12548-53 - PubMed
  26. Glia. 2012 Aug;60(8):1192-202 - PubMed
  27. Nat Rev Neurol. 2009 Jul;5(7):380-91 - PubMed
  28. Exp Neurol. 2008 Apr;210(2):762-75 - PubMed
  29. Nan Fang Yi Ke Da Xue Xue Bao. 2010 Dec;30(12):2738-41 - PubMed
  30. Cell Biol Toxicol. 2006 Mar;22(2):119-25 - PubMed
  31. J Biol Chem. 2008 Apr 18;283(16):10347-56 - PubMed
  32. J Pharmacol Exp Ther. 2001 Sep;298(3):1033-41 - PubMed
  33. J Neurosci. 2003 Feb 1;23(3):1013-8 - PubMed
  34. Nat Rev Neurosci. 2006 Mar;7(3):194-206 - PubMed
  35. Eur J Neurosci. 2000 Jun;12(6):2039-48 - PubMed
  36. Neuroscience. 2002;115(4):1067-78 - PubMed
  37. Rev Neurosci. 2002;13(1):1-30 - PubMed
  38. Epilepsy Res. 1996 Dec;26(1):163-75 - PubMed
  39. Neuroscientist. 2002 Jun;8(3):254-67 - PubMed
  40. Brain Res Brain Res Rev. 2000 Apr;32(1):308-15 - PubMed
  41. FEBS Lett. 2004 Aug 13;572(1-3):65-8 - PubMed
  42. Glia. 2006 Nov 15;54(7):700-15 - PubMed
  43. Eur J Neurosci. 2007 Apr;25(7):2170-81 - PubMed
  44. Prog Biophys Mol Biol. 2007 May-Jun;94(1-2):245-64 - PubMed
  45. Epilepsia. 2006 Jul;47(7):1169-75 - PubMed
  46. Mol Cell Neurosci. 2002 Sep;21(1):94-113 - PubMed
  47. J Neurosci. 2009 Jun 17;29(24):7743-52 - PubMed
  48. Neurobiol Dis. 2009 May;34(2):291-9 - PubMed
  49. Glia. 2011 Jul;59(7):1064-74 - PubMed
  50. Eur J Neurosci. 2003 Oct;18(7):1807-27 - PubMed
  51. Dev Neurosci. 2001;23(6):420-31 - PubMed
  52. Adv Exp Med Biol. 2004;548:110-22 - PubMed
  53. Curr Pharm Des. 2010;16(28):3056-70 - PubMed
  54. Eur J Neurosci. 2012 Jan;35(1):76-82 - PubMed
  55. Epilepsy Res. 2006 Oct;71(2-3):223-8 - PubMed
  56. Histol Histopathol. 2005 Jan;20(1):253-9 - PubMed
  57. J Neurophysiol. 2002 Oct;88(4):1893-902 - PubMed
  58. Am J Pathol. 2012 Sep;181(3):746-52 - PubMed
  59. Neuroscience. 2009 Jan 12;158(1):137-48 - PubMed
  60. J Pharmacol Exp Ther. 1991 Oct;259(1):235-40 - PubMed
  61. Epilepsia. 2003 Dec;44(12):1596-600 - PubMed
  62. Matrix Biol. 2012 Apr;31(3):170-7 - PubMed
  63. Epilepsy Res. 2010 Dec;92(2-3):153-62 - PubMed
  64. J Clin Invest. 2011 May;121(5):2037-47 - PubMed
  65. Ann Neurol. 2004 Jul;56(1):108-15 - PubMed
  66. Brain Res Mol Brain Res. 2000 Nov 10;83(1-2):44-51 - PubMed
  67. J Neurophysiol. 2011 Jan;105(1):172-87 - PubMed
  68. Mol Chem Neuropathol. 1998 Aug-Dec;35(1-3):23-37 - PubMed
  69. Mol Med Rep. 2013 Dec;8(6):1801-6 - PubMed
  70. Brain Res Brain Res Rev. 2000 Apr;32(1):57-71 - PubMed
  71. Science. 2005 Oct 7;310(5745):113-6 - PubMed
  72. Neurochem Int. 2004 Sep;45(4):453-66 - PubMed
  73. Pflugers Arch. 2009 Apr;457(6):1207-26 - PubMed
  74. Neuropharmacology. 2007 Feb;52(2):362-7 - PubMed
  75. PLoS One. 2012;7(11):e51124 - PubMed
  76. Nature. 1998 Jul 9;394(6689):189-92 - PubMed
  77. Biochem Biophys Res Commun. 2011 Jun 17;409(4):603-9 - PubMed
  78. Trends Neurosci. 2010 Feb;33(2):93-102 - PubMed
  79. Neuroscience. 2011 Sep 29;192:11-9 - PubMed
  80. Mol Cell Biochem. 2008 Aug;315(1-2):41-9 - PubMed
  81. Brain Res Brain Res Rev. 2000 Apr;32(1):235-41 - PubMed
  82. Acta Physiol Scand. 2003 Sep;179(1):5-8 - PubMed
  83. Brain Res. 2008 Jan 2;1187:74-81 - PubMed
  84. Mol Biol Cell. 2008 Aug;19(8):3501-13 - PubMed
  85. J Neurol. 2002 May;249(5):584-95 - PubMed
  86. Genomics. 2004 Apr;83(4):706-16 - PubMed
  87. J Biol Chem. 2007 Oct 26;282(43):31733-43 - PubMed
  88. Eur J Neurosci. 2014 Jan;39(1):46-60 - PubMed
  89. J Cereb Blood Flow Metab. 2011 Mar;31(3):819-31 - PubMed
  90. Neurobiol Dis. 2006 Jun;22(3):496-508 - PubMed
  91. J Gen Physiol. 2008 Sep;132(3):315-27 - PubMed
  92. J Neurochem. 2010 Jan;112(1):92-102 - PubMed
  93. Science. 2008 Dec 5;322(5907):1551-5 - PubMed
  94. J Neural Transm (Vienna). 2014 Aug;121(8):837-46 - PubMed
  95. Curr Opin Neurobiol. 2011 Apr;21(2):353-9 - PubMed
  96. Electroencephalogr Clin Neurophysiol Suppl. 1978;(34):289-97 - PubMed
  97. Biochem Soc Trans. 2001 Aug;29(Pt 4):606-12 - PubMed
  98. Biochim Biophys Acta. 2005 Jun 10;1711(2):215-24 - PubMed
  99. Biophys J. 1994 Nov;67(5):1816-22 - PubMed
  100. PLoS One. 2011;6(9):e25178 - PubMed
  101. Epilepsia. 2005 Apr;46(4):470-2 - PubMed
  102. Nat Rev Neurosci. 2014 Apr;15(4):250-63 - PubMed
  103. J Neurophysiol. 2003 Apr;89(4):2046-54 - PubMed
  104. Epilepsia. 2009 Aug;50(8):1971-8 - PubMed
  105. Dev Biol. 1996 Apr 10;175(1):50-6 - PubMed
  106. Biol Chem. 2002 May;383(5):725-37 - PubMed
  107. Exp Neurol. 1991 Feb;111(2):198-203 - PubMed
  108. J Membr Biol. 2007 Jun;217(1-3):21-33 - PubMed
  109. Epilepsia. 2007;48 Suppl 5:35-40 - PubMed
  110. J Biol Chem. 2011 Aug 5;286(31):27639-53 - PubMed
  111. Biochim Biophys Acta. 2013 Jan;1828(1):23-34 - PubMed
  112. Nat Neurosci. 1998 Oct;1(6):494-500 - PubMed
  113. Neuroscience. 1999;92(2):407-26 - PubMed
  114. Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10942-7 - PubMed
  115. J Neurosci. 1994 Jul;14(7):4308-17 - PubMed
  116. J Cell Sci. 2007 Nov 1;120(Pt 21):3772-83 - PubMed
  117. Physiol Rev. 1995 Oct;75(4):689-723 - PubMed
  118. Proc Natl Acad Sci U S A. 2004 Aug 17;101(33):12364-9 - PubMed
  119. Eur J Pharmacol. 2002 Jul 5;447(2-3):227-37 - PubMed
  120. Biochim Biophys Acta. 2005 Dec 20;1719(1-2):36-58 - PubMed
  121. Biophys J. 2003 Jan;84(1):277-86 - PubMed
  122. Prog Neuropsychopharmacol Biol Psychiatry. 2010 Apr 16;34(3):510-5 - PubMed
  123. J Physiol. 2004 Aug 1;558(Pt 3):825-39 - PubMed
  124. Cell Commun Adhes. 2007 Nov-Dec;14(6):259-64 - PubMed
  125. Biochim Biophys Acta. 2005 Dec 20;1719(1-2):59-68 - PubMed
  126. Front Cell Neurosci. 2013 Jul 16;7:109 - PubMed
  127. J Physiol. 2003 Dec 15;553(Pt 3):729-45 - PubMed
  128. FEBS Lett. 2014 Apr 17;588(8):1372-8 - PubMed
  129. Neuroscience. 2009 Sep 29;163(1):202-12 - PubMed
  130. Brain Res. 2012 Dec 3;1487:54-60 - PubMed
  131. Neuroscience. 2001;105(3):579-87 - PubMed
  132. Cell Biol Int. 1998 Nov;22(11-12):793-805 - PubMed
  133. Brain Res. 2002 Mar 1;929(1):105-16 - PubMed
  134. Brain Res Rev. 2010 May;63(1-2):160-76 - PubMed
  135. Neurobiol Dis. 2013 Jun;54:68-81 - PubMed
  136. Nat Cell Biol. 2007 Aug;9(8):945-53 - PubMed
  137. Epilepsia. 2005 Aug;46(8):1188-97 - PubMed
  138. Epilepsy Behav. 2005 Sep;7(2):190-203 - PubMed
  139. Front Pharmacol. 2013 Jul 17;4:88 - PubMed
  140. J Membr Biol. 2007 Oct;219(1-3):9-17 - PubMed
  141. Neuron. 2001 Aug 16;31(3):487-95 - PubMed
  142. Acta Neuropathol. 2001 May;101(5):449-59 - PubMed
  143. Cell Res. 2008 May;18(5):558-65 - PubMed
  144. Mol Biol Cell. 2009 Oct;20(20):4313-23 - PubMed
  145. Cardiovasc Res. 2004 May 1;62(2):228-32 - PubMed
  146. J Neurosci. 1995 Jan;15(1 Pt 1):30-46 - PubMed
  147. Channels (Austin). 2008 Mar-Apr;2(2):81-6 - PubMed
  148. J Neurochem. 2003 Aug;86(3):687-99 - PubMed
  149. Neuron. 2009 Jun 11;62(5):612-32 - PubMed
  150. Exp Neurol. 1997 May;145(1):154-64 - PubMed
  151. Trends Neurosci. 2000 Feb;23(2):68-74 - PubMed
  152. Clin Neurophysiol. 2009 Apr;120(4):673-8 - PubMed
  153. J Clin Neurophysiol. 2005 Oct;22(5):330-42 - PubMed
  154. Trends Neurosci. 2003 Nov;26(11):610-7 - PubMed
  155. Neurobiol Dis. 2010 Dec;40(3):573-85 - PubMed
  156. J Neurochem. 2005 Mar;92(5):1033-43 - PubMed
  157. Neuroscience. 2000;100(4):789-96 - PubMed

Publication Types