Siarhei A Siapich1,2, Isha Akhtar1, Jürgen Hescheler1, Toni Schneider3, Matthias Lüke1,4. 1. Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, D-50931, Köln, Germany. 2. Department of Ophthalmology, RWTH Aachen University, Pauwelsstr. 30, D-52074, Aachen, Germany. 3. Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, D-50931, Köln, Germany. toni.schneider@uni-koeln.de. 4. University Eye Hospital, University of Lübeck, Ratzeburger Allee 160, D-23538, Lübeck, Germany.
Abstract
BACKGROUND: The model of the isolated and superfused retina provides the opportunity to test drugs and toxins. Some chemicals have to be applied using low concentrations of organic solvents as carriers. Recently, E-/R-type (Cav2.3) and T-type (Cav3.2) voltage-gated Ca(2+) channels were identified as participating in reciprocal inhibitory retinal signaling. Their participation is apparent, when low concentrations of NiCl2 (15 μM) are applied during superfusion leading to an increase of the ERG b-wave amplitude, which is explained by a reduction of amacrine GABA-release onto bipolar neurons. During these investigations, differences were observed for the solvent carrier used. METHODS: Recording of the transretinal receptor potentials from the isolated bovine retina. RESULTS: The pretreatment of bovine retina with 0.01 % (v/v) dimethylsulfoxide did not impair the NiCl2-mediated increase of the b-wave amplitude, which was 1.31-fold ± 0.03 of initial value (n = 4). However, pretreatment of the retina with the same concentration of ethanol impaired reciprocal signaling (0.96-fold ± 0.05, n = 4). Further, the implicit time of the b-wave was increased, suggesting that ethanol itself but not DMSO may antagonize GABA-receptors. CONCLUSION: Ethanol itself but not DMSO may block GABA receptors and cause an amplitude increase by itself, so that reciprocal signaling is impaired.
BACKGROUND: The model of the isolated and superfused retina provides the opportunity to test drugs and toxins. Some chemicals have to be applied using low concentrations of organic solvents as carriers. Recently, E-/R-type (Cav2.3) and T-type (Cav3.2) voltage-gated Ca(2+) channels were identified as participating in reciprocal inhibitory retinal signaling. Their participation is apparent, when low concentrations of NiCl2 (15 μM) are applied during superfusion leading to an increase of the ERG b-wave amplitude, which is explained by a reduction of amacrine GABA-release onto bipolar neurons. During these investigations, differences were observed for the solvent carrier used. METHODS: Recording of the transretinal receptor potentials from the isolated bovine retina. RESULTS: The pretreatment of bovine retina with 0.01 % (v/v) dimethylsulfoxide did not impair the NiCl2-mediated increase of the b-wave amplitude, which was 1.31-fold ± 0.03 of initial value (n = 4). However, pretreatment of the retina with the same concentration of ethanol impaired reciprocal signaling (0.96-fold ± 0.05, n = 4). Further, the implicit time of the b-wave was increased, suggesting that ethanol itself but not DMSO may antagonize GABA-receptors. CONCLUSION:Ethanol itself but not DMSO may block GABA receptors and cause an amplitude increase by itself, so that reciprocal signaling is impaired.
Authors: M Lüke; M Warga; F Ziemssen; F Gelisken; S Grisanti; T Schneider; C Lüke; M Partsch; K U Bartz-Schmidt; P Szurman Journal: Br J Ophthalmol Date: 2006-06-05 Impact factor: 4.638
Authors: Luis Bonet-Ponce; Sara Saez-Atienzar; Carmen da Casa; Miguel Flores-Bellver; Jorge M Barcia; Javier Sancho-Pelluz; Francisco J Romero; Joaquín Jordan; María F Galindo Journal: Biochim Biophys Acta Date: 2015-03-13
Authors: T Schneider; X Wei; R Olcese; J L Costantin; A Neely; P Palade; E Perez-Reyes; N Qin; J Zhou; G D Crawford Journal: Receptors Channels Date: 1994
Authors: Yuri A Blednov; Jillian M Benavidez; Mendy Black; Courtney R Leiter; Elizabeth Osterndorff-Kahanek; David Johnson; Cecilia M Borghese; Jane R Hanrahan; Graham A R Johnston; Mary Chebib; R Adron Harris Journal: PLoS One Date: 2014-01-16 Impact factor: 3.240