Journal of Molecular Neuroscience

, Volume 58, Issue 2, pp 178–192 | Cite as

Expression and Localization of Connexins in the Outer Retina of the Mouse

  • Petra Bolte
  • Regina Herrling
  • Birthe Dorgau
  • Konrad Schultz
  • Andreas Feigenspan
  • Reto Weiler
  • Karin DedekEmail author
  • Ulrike Janssen-BienholdEmail author


The identification of the proteins that make up the gap junction channels between rods and cones is of crucial importance to understand the functional role of photoreceptor coupling within the retinal network. In vertebrates, connexin proteins constitute the structural components of gap junction channels. Connexin36 is known to be expressed in cones whereas extensive investigations have failed to identify the corresponding connexin expressed in rods. Using immunoelectron microscopy, we demonstrate that connexin36 (Cx36) is present in gap junctions of cone but not rod photoreceptors in the mouse retina. To identify the rod connexin, we used nested reverse transcriptase polymerase chain reaction and tested retina and photoreceptor samples for messenger RNA (mRNA) expression of all known connexin genes. In addition to connexin36, we detected transcripts for connexin32, connexin43, connexin45, connexin50, and connexin57 in photoreceptor samples. Immunohistochemistry showed that connexin43, connexin45, connexin50, and connexin57 proteins are expressed in the outer plexiform layer. However, none of these connexins was detected at gap junctions between rods and cones as a counterpart of connexin36. Therefore, the sought-after rod protein must be either an unknown connexin sequence, a connexin36 splice product not detected by our antibodies, or a protein from a further gap junction protein family.


Connexin Electrical synapse Gap junction Photoreceptor Retina Rod–cone coupling 



We thank Bettina Kewitz and Susanne Wallenstein for excellent technical assistance and gratefully acknowledge the following funding: European Commission FP7 Grant RETICIRC HEALTH-F2-2009-223156 and MWK 99-20/08 (I/83 876) (to R.W.), Deutsche Forschungsgemeinschaft DE1154/5-1 (to K.D), and Deutsche Forschungsgemeinschaft JA854/1-2 and JA854/3-1 (to U.J.B).

Supplementary material

12031_2015_654_Fig7_ESM.gif (75 kb)
Fig. S1

RT-PCR with intron-spanning rhodopsin primers. PCRs confirmed successful reverse transcription of photoreceptor (PR) and mouse retinal (MR) cDNA and that none of the samples contained genomic DNA. The rhodopsin specific primer set revealed an amplicon with a predicted size of 332 bp on cDNA and 453 bp when the amplification is based on genomic DNA (gen). Negative controls (NC) were performed with water. (GIF 75 kb)

12031_2015_654_MOESM1_ESM.tif (850 kb)
High resolution image (TIFF 849 kb)


  1. Abascal F, Zardoya R (2012) LRRC8 proteins share a common ancestor with pannexins, and may form hexameric channels involved in cell-cell communication. BioEssays News Rev Mol Cell Dev Biol 34:551–560CrossRefGoogle Scholar
  2. Asteriti S, Gargini C, Cangiano L (2014) Mouse rods signal through gap junctions with cones. eLife 3:e01386PubMedCentralCrossRefPubMedGoogle Scholar
  3. Balen D, Ljubojevic M, Breljak D et al (2008) Revised immunolocalization of the Na+-D-glucose cotransporter SGLT1 in rat organs with an improved antibody. Am J Physiol Cell Physiol 295:C475–C489CrossRefPubMedGoogle Scholar
  4. Ball AK, McReynolds JS (1998) Localization of gap junctions and tracer coupling in retinal Müller cells. J Comp Neurol 393:48–57CrossRefPubMedGoogle Scholar
  5. Beyer EC, Paul DL, Goodenough DA (1987) Connexin43: a protein from rat heart homologous to a gap junction protein from liver. J Cell Biol 105:2621–2629CrossRefPubMedGoogle Scholar
  6. Boassa D, Ambrosi C, Qiu F et al (2007) Pannexin1 channels contain a glycosylation site that targets the hexamer to the plasma membrane. J Biol Chem 282:31733–31743CrossRefPubMedGoogle Scholar
  7. Dang L, Pulukuri S, Mears AJ et al (2004) Connexin 36 in photoreceptor cells: studies on transgenic rod-less and cone-less mouse retinas. Mol Vis 10:323–327PubMedGoogle Scholar
  8. Deans M, Völgyi B, Goodenough D et al (2002) Connexin36 is essential for transmission of rod-mediated visual signals in the mammalian retina. Neuron 36:703–12PubMedCentralCrossRefPubMedGoogle Scholar
  9. Dedek K, Breuninger T, de Sevilla Müller LP et al (2009) A novel type of interplexiform amacrine cell in the mouse retina. Eur J Neurosci 30:217–228CrossRefPubMedGoogle Scholar
  10. Dedek K, Schultz K, Pieper M et al (2006) Localization of heterotypic gap junctions composed of connexin45 and connexin36 in the rod pathway of the mouse retina. Eur J Neurosci 24:1675–86CrossRefPubMedGoogle Scholar
  11. DeVries SH, Qi X, Smith R et al (2002) Electrical coupling between mammalian cones. Curr Biol 12:1900–1907CrossRefPubMedGoogle Scholar
  12. Dorgau B, Herrling R, Schultz K et al (2015) Connexin50 couples axon terminals of mouse horizontal cells by homotypic gap junctions. J Comp Neurol. doi: 10.1002/cne.23779 PubMedGoogle Scholar
  13. Feigenspan A, Janssen-Bienhold U, Hormuzdi S et al (2004) Expression of connexin36 in cone pedicles and OFF-cone bipolar cells of the mouse retina. J Neurosci 24:3325–34CrossRefPubMedGoogle Scholar
  14. Feigenspan A, Teubner B, Willecke K, Weiler R (2001) Expression of neuronal connexin36 in AII amacrine cells of the mammalian retina. J Neurosci 21:230–239PubMedGoogle Scholar
  15. Foote CI, Zhou L, Zhu X, Nicholson BJ (1998) The pattern of disulfide linkages in the extracellular loop regions of connexin 32 suggests a model for the docking interface of gap junctions. J Cell Biol 140:1187–1197PubMedCentralCrossRefPubMedGoogle Scholar
  16. Güldenagel M, Söhl G, Plum A et al (2000) Expression patterns of connexin genes in mouse retina. J Comp Neurol 425:193–201CrossRefPubMedGoogle Scholar
  17. Han Y, Massey SC (2005) Electrical synapses in retinal ON cone bipolar cells: subtype-specific expression of connexins. Proc Natl Acad Sci USA 102:13313--13318Google Scholar
  18. Hilgen G, von Maltzahn J, Willecke K et al (2011) Subcellular distribution of connexin45 in OFF bipolar cells of the mouse retina. J Comp Neurol 519:433–450CrossRefPubMedGoogle Scholar
  19. Hombach S, Janssen-Bienhold U, Söhl G et al (2004) Functional expression of connexin57 in horizontal cells of the mouse retina. Eur J Neurosci 19:2633–40CrossRefPubMedGoogle Scholar
  20. Hornstein EP, Verweij J, Li PH, Schnapf JL (2005) Gap-junctional coupling and absolute sensitivity of photoreceptors in macaque retina. J Neurosci 25:11201–11209CrossRefPubMedGoogle Scholar
  21. Hornstein EP, Verweij J, Schnapf JL (2004) Electrical coupling between red and green cones in primate retina. Nat Neurosci 7:745–750CrossRefPubMedGoogle Scholar
  22. Janssen-Bienhold U, Dermietzel R, Weiler R (1998) Distribution of connexin43 immunoreactivity in the retinas of different vertebrates. J Comp Neurol 396:310–21CrossRefPubMedGoogle Scholar
  23. Janssen-Bienhold U, Trümpler J, Hilgen G et al (2009) Connexin57 is expressed in dendro-dendritic and axo-axonal gap junctions of mouse horizontal cells and its distribution is modulated by light. J Comp Neurol 513:363–74CrossRefPubMedGoogle Scholar
  24. Jeon CJ, Strettoi E, Masland RH (1998) The major cell populations of the mouse retina. J Neurosci 18:8936–46PubMedGoogle Scholar
  25. Katti C, Butler R, Sekaran S (2013) Diurnal and circadian regulation of connexin 36 transcript and protein in the mammalian retina. Invest Ophthalmol Vis Sci 54:821–9CrossRefPubMedGoogle Scholar
  26. Kihara AH, Mantovani de Castro L, Belmonte MA et al (2006) Expression of connexins 36, 43, and 45 during postnatal development of the mouse retina. J Neurobiol 66:1397–1410CrossRefPubMedGoogle Scholar
  27. Kolb H, Jones J (1985) Electron microscopy of golgi-impregnated photoreceptors reveals connections between red and green cones in turtle retina. J Neurophysiol 54:304--317Google Scholar
  28. Kreuzberg MM (2005) Functional properties of mouse connexin30.2 expressed in the conduction system of the heart. Circ Res 96:1169–1177PubMedCentralCrossRefPubMedGoogle Scholar
  29. Kumar NM, Gilula NB (1996) The gap junction communication channel. Cell 84:381–8CrossRefPubMedGoogle Scholar
  30. Lamb TD, Simon EJ (1976) The relation between intercellular coupling and electrical noise in turtle photoreceptors. J Physiol 263:257–286PubMedCentralCrossRefPubMedGoogle Scholar
  31. Lee E-J, Han J-W, Kim H-J et al (2003) The immunocytochemical localization of connexin 36 at rod and cone gap junctions in the guinea pig retina. Eur J Neurosci 18:2925–2934CrossRefPubMedGoogle Scholar
  32. Li H, Chuang AZ, O’Brien J (2009) Photoreceptor coupling is controlled by connexin 35 phosphorylation in zebrafish retina. J Neurosci 29:15178–15186PubMedCentralCrossRefPubMedGoogle Scholar
  33. Li H, Zhang Z, Blackburn MR et al (2013) Adenosine and dopamine receptors coregulate photoreceptor coupling via gap junction phosphorylation in mouse retina. J Neurosci 33:3135–3150PubMedCentralCrossRefPubMedGoogle Scholar
  34. Li PH, Verweij J, Long JH, Schnapf JL (2012) Gap-junctional coupling of mammalian rod photoreceptors and its effect on visual detection. J Neurosci 32:3552–3562PubMedCentralCrossRefPubMedGoogle Scholar
  35. Maxeiner S, Dedek K, Janssen-Bienhold U et al (2005) Deletion of connexin45 in mouse retinal neurons disrupts the rod/cone signaling pathway between AII amacrine and ON cone bipolar cells and leads to impaired visual transmission. J Neurosci 25:566–576CrossRefPubMedGoogle Scholar
  36. Meyer A, Hilgen G, Dorgau B et al (2014) AII amacrine cells discriminate between heterocellular and homocellular locations when assembling connexin36-containing gap junctions. J Cell Sci 127:1190–202PubMedCentralCrossRefPubMedGoogle Scholar
  37. O’Brien JJ, Chen X, Macleish PR et al (2012) Photoreceptor coupling mediated by connexin36 in the primate retina. J Neurosci 32:4675–4687PubMedCentralCrossRefPubMedGoogle Scholar
  38. O’Brien JJ, Li W, Pan F et al (2006) Coupling between A-type horizontal cells is mediated by connexin 50 gap junctions in the rabbit retina. J Neurosci 26:11624–11636CrossRefPubMedGoogle Scholar
  39. Pan F, Paul DL, Bloomfield SA, Völgyi B (2010) Connexin36 is required for gap junctional coupling of most ganglion cell subtypes in the mouse retina. J Comp Neurol 518:911–927PubMedCentralCrossRefPubMedGoogle Scholar
  40. Pérez De Sevilla Müller L, Dedek K, Janssen-Bienhold U et al (2010) Expression and modulation of connexin30.2, a novel gap junction protein in the mouse retina. Vis Neurosci 27:91–101CrossRefGoogle Scholar
  41. Postma FR, Keung J, Paul D, Massey SC (2010) Cone telodendria form the substrate for photoreceptor coupling. ARVO Meet Abstr 51:2046Google Scholar
  42. Raviola E, Gilula NB (1973) Gap junctions between photoreceptor cells in the vertebrate retina. Proc Natl Acad Sci U S A 70:1677–1681PubMedCentralCrossRefPubMedGoogle Scholar
  43. Ribelayga C, Cao Y, Mangel SC (2008) The circadian clock in the retina controls rod-cone coupling. Neuron 59:790–801CrossRefPubMedGoogle Scholar
  44. Ribelayga C, Mangel SC (2010) Identification of a circadian clock-controlled neural pathway in the rabbit retina. PloS One 5:e11020PubMedCentralCrossRefPubMedGoogle Scholar
  45. Schneeweis DM, Schnapf JL (1999) The photovoltage of macaque cone photoreceptors: adaptation, noise, and kinetics. J Neurosci 19:1203–1216PubMedGoogle Scholar
  46. Schubert T, Degen J, Willecke K et al (2005a) Connexin36 mediates gap junctional coupling of alpha-ganglion cells in mouse retina. J Comp Neurol 485:191–201CrossRefPubMedGoogle Scholar
  47. Schubert T, Maxeiner S, Krüger O et al (2005b) Connexin45 mediates gap junctional coupling of bistratified ganglion cells in the mouse retina. J Comp Neurol 490:29–39CrossRefPubMedGoogle Scholar
  48. Siebert AP, Ma Z, Grevet JD et al (2013) Structural and functional similarities of calcium homeostasis modulator 1 (CALHM1) ion channel with connexins, pannexins, and innexins. J Biol Chem 288:6140–6153PubMedCentralCrossRefPubMedGoogle Scholar
  49. Smith RG, Freed MA, Sterling P (1986) Microcircuitry of the dark-adapted cat retina: functional architecture of the rod-cone network. J Neurosci 6:3505–3517PubMedGoogle Scholar
  50. Söhl G, Güldenagel M, Traub O, Willecke K (2000) Connexin expression in the retina. Brain Res Brain Res Rev 32:138–145CrossRefPubMedGoogle Scholar
  51. Söhl G, Willecke K (2003) An update on connexin genes and their nomenclature in mouse and man. Cell Commun Adhes 10:173–80CrossRefPubMedGoogle Scholar
  52. Stöhr H, Molday LL, Molday RS et al (2005) Membrane-associated guanylate kinase proteins MPP4 and MPP5 associate with Veli3 at distinct intercellular junctions of the neurosensory retina. J Comp Neurol 481:31–41CrossRefPubMedGoogle Scholar
  53. Trümpler J, Dedek K, Schubert T et al (2008) Rod and cone contributions to horizontal cell light responses in the mouse retina. J Neurosci 28:6818–25CrossRefPubMedGoogle Scholar
  54. Tsukamoto Y, Morigiwa K, Ueda M, Sterling P (2001) Microcircuits for night vision in mouse retina. J Neurosci 21:8616–8623PubMedGoogle Scholar
  55. Völgyi B, Deans M, Paul D, Bloomfield S (2004) Convergence and segregation of the multiple rod pathways in mammalian retina. J Neurosci 24:11182–92PubMedCentralCrossRefPubMedGoogle Scholar
  56. Voss FK, Ullrich F, Münch J et al (2014) Identification of LRRC8 heteromers as an essential component of the volume-regulated anion channel VRAC. Science 344:634–638CrossRefPubMedGoogle Scholar
  57. White TW, Goodenough DA, Paul DL (1998) Targeted ablation of connexin50 in mice results in microphthalmia and zonular pulverulent cataracts. J Cell Biol 143:815–825PubMedCentralCrossRefPubMedGoogle Scholar
  58. Wu SM, Yang XL (1988) Electrical coupling between rods and cones in the tiger salamander retina. Proc Natl Acad Sci 85:275–278PubMedCentralCrossRefPubMedGoogle Scholar
  59. Zhang J, Wu SM (2004) Physiological properties of rod photoreceptor electrical coupling in the tiger salamander. J Physiol 564:849--862Google Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Petra Bolte
    • 1
    • 3
  • Regina Herrling
    • 1
  • Birthe Dorgau
    • 1
    • 5
  • Konrad Schultz
    • 1
  • Andreas Feigenspan
    • 1
    • 4
  • Reto Weiler
    • 1
    • 2
  • Karin Dedek
    • 1
    • 2
    Email author
  • Ulrike Janssen-Bienhold
    • 1
    • 2
    Email author
  1. 1.Neurobiology Group, Department for Neuroscience, School of Medicine and Health SciencesUniversity of OldenburgOldenburgGermany
  2. 2.Research Center Neurosensory ScienceUniversity of OldenburgOldenburgGermany
  3. 3.Animal NavigationUniversity of OldenburgOldenburgGermany
  4. 4.Animal Physiology, FAU Erlangen-NurembergErlangenGermany
  5. 5.Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK

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