Neurobiology

Electrical synapses

Electrical synapses (gap junctions) permit fast transmission of electrical signals and passage of metabolites by means of channels, which directly connect the cytoplasm of adjoining cells. A functional gap junction channel consists of two hemichannels (one provided by each of the cells), each comprised of a set of six protein subunits, termed connexins. These building blocks exist in a variety of different subtypes, and the connexin composition determines permeability and gating properties of a gap junction channel, thereby enabling electrical synapses to meet a diversity of physiological requirements.

In the retina, various connexins are expressed in different cell types. We study the cellular distribution of different connexins as well as the modulation induced by transmitter action or change of ambient light levels, which leads to altered electrical coupling properties.

 

Related Publications

Meyer A, Hilgen G, Dorgau B, Sammler EM, Weiler R, Monyer H, Dedek K, Hormuzdi SG. 2014. AII amacrine cells discriminate between heterocellular and homocellular locations when assembling connexin36-containing gap junctions. J Cell Sci. PubMed

Kranz K, Paquet-Durand F, Weiler R, Janssen-Bienhold U, Dedek K. 2013. Testing for a gap junction-mediated bystander effect in retinitis pigmentosa: secondary cone death is not altered by deletion of connexin36 from cones. PLoS One. 8, e57163. PubMed

Hilgen G, von Maltzahn J, Willecke K, Weiler R, Dedek K. 2011. Subcellular distribution of connexin45 in OFF bipolar cells of the mouse retina. J Comp Neurol. 519, 433-450. PubMed

Pérez de Sevilla Müller L, Dedek K, Janssen-Bienhold U, Meyer A, Kreuzberg MM, Lorenz S, Willecke K, Weiler R. 2010. Expression and modulation of connexin 30.2, a novel gap junction protein in the mouse retina. Vis Neurosci. 27, 91-101. PubMed

Janssen-Bienhold U, Trümpler J, Hilgen G, Schultz K, Pérez de Sevilla Müller L, Sonntag S, Dedek K, Dirks P, Willecke K, Weiler R. 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, 363-374. PubMed

Dedek K, Schultz K, Pieper M, Dirks P, Maxeiner S, Willecke K, Weiler R, Janssen-Bienhold U. 2006. Localization of heterotypic gap junctions composed of connexin45 and connexin36 in the rod pathway of the mouse retina. Eur J Neurosci. 24, 1675-1686. PubMed

Urschel S, Höher T, Schubert T, Alev C, Söhl G, Wörsdörfer P, Asahara T, Dermietzel R, Weiler R, Willecke K. 2006. Protein kinase A-mediated phosphorylation of connexin36 in mouse retina results in decreased gap junctional communication between AII amacrine cells. J Biol Chem. 281, 33163-33171. PubMed

Shelley J, Dedek K, Schubert T, Feigenspan A, Schultz K, Hombach S, Willecke K, Weiler R. 2006. Horizontal cell receptive fields are reduced in connexin57-deficient mice. Eur J Neurosci. 23, 3176-3186. PubMed