Brain Structure and Function

, Volume 221, Issue 6, pp 2963–2984 | Cite as

Characterization of connexin36 gap junctions in the human outer retina

  • Orsolya Kántor
  • Zsigmond Benkő
  • Anna Énzsöly
  • Csaba Dávid
  • Angela Naumann
  • Roland Nitschke
  • Arnold Szabó
  • Emese Pálfi
  • József Orbán
  • Miklós Nyitrai
  • János Németh
  • Ágoston Szél
  • Ákos Lukáts
  • Béla VölgyiEmail author
Original Article


Retinal connexins (Cx) form gap junctions (GJ) in key circuits that transmit average or synchronize signals. Expression of Cx36, -45, -50 and -57 have been described in many species but there is still a disconcerting paucity of information regarding the Cx makeup of human retinal GJs. We used well-preserved human postmortem samples to characterize Cx36 GJ constituent circuits of the outer plexiform layer (OPL). Based on their location, morphometric characteristics and co-localizations with outer retinal neuronal markers, we distinguished four populations of Cx36 plaques in the human OPL. Three of these were comprised of loosely scattered Cx36 plaques; the distalmost population 1 formed cone-to-rod GJs, population 2 in the mid-OPL formed cone-to-cone GJs, whereas the proximalmost population 4 likely connected bipolar cell dendrites. The fourth population (population 3) of Cx36 plaques conglomerated beneath cone pedicles and connected dendritic tips of bipolar cells that shared a common presynaptic cone. Overall, we show that the human outer retina displays a diverse cohort of Cx36 GJ that follows the general mammalian scheme and display a great functional diversity.


Gap junction Electrical synapse Photoreceptor Cone Rod Bipolar cell 



The authors thank to Zsuzsanna Vidra for her technical help and are grateful to Dr. Mark Eyre for the assistance with the English language. The authors are thankful for providing the antibodies: Noga Vardi (mGluR6), Wilhelm Koch (recoverin), Alán Alpár (guinea pig calbindin), Norbert Hájos (GluA4N). Supported by OTKA K105247 to B.V. and OTKA 73000 Á.S. This research was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP-4.2.4.A/2-11/1-2012-0001 ‘National Excellence Program’.to B.V. Finally, B.V. was also supported by the Hungarian Brain Research Program (KTIA_NAP_13-2-2015-0008).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical standards

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee (number of permission: TUKEB 58/2006) and with the 1964 Helsinki declaration and its later amendments.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Orsolya Kántor
    • 1
  • Zsigmond Benkő
    • 2
    • 3
  • Anna Énzsöly
    • 4
    • 5
  • Csaba Dávid
    • 5
  • Angela Naumann
    • 6
    • 7
  • Roland Nitschke
    • 6
    • 7
  • Arnold Szabó
    • 5
  • Emese Pálfi
    • 1
  • József Orbán
    • 8
    • 9
  • Miklós Nyitrai
    • 8
    • 9
  • János Németh
    • 4
  • Ágoston Szél
    • 5
  • Ákos Lukáts
    • 5
  • Béla Völgyi
    • 9
    • 10
    • 11
    • 12
    Email author
  1. 1.Department of Anatomy, Histology and EmbryologySemmelweis UniversityBudapestHungary
  2. 2.Department of TheoryWigner Research Center for Physics of the Hungarian Academy of SciencesBudapestHungary
  3. 3.Semmelweis University School of Ph.D. StudiesBudapestHungary
  4. 4.Department of OphthalmologySemmelweis UniversityBudapestHungary
  5. 5.Department of Human Morphology and Developmental BiologySemmelweis UniversityBudapestHungary
  6. 6.Life Imaging Center, Center for Biological Systems AnalysisAlbert-Ludwigs UniversityFreiburgGermany
  7. 7.BIOSS Centre for Biological Signalling StudiesAlbert-Ludwigs-University FreiburgFreiburgGermany
  8. 8.Department of BiophysicsUniversity of PécsPécsHungary
  9. 9.János Szentágothai Research CenterUniversity of PécsPécsHungary
  10. 10.MTA-PTE NAP B Retinal Electrical Synapses Research GroupPécsHungary
  11. 11.Department of Experimental Zoology and NeurobiologyUniversity of PécsPécsHungary
  12. 12.Department of OphthalmologyNew York University Langone Medical CenterNew YorkUSA

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