Journal article
Two separate Ni 2+ ‐sensitive voltage‐gated Ca 2+ channels modulate transretinal signalling in the isolated murine retina
Acta ophthalmologica (Oxford, England), Vol.89(7), pp.e579-e590
11/2011
DOI: 10.1111/j.1755-3768.2011.02167.x
PMID: 21883984
Abstract
Purpose: Light-evoked responses from vertebrate retinas were recorded as an electroretinogram (ERG). The b-wave is the most prominent component of the ERG, and in the bovine retina its NiCl(2) -sensitive component was attributed to reciprocal signalling by pharmacoresistant R-type voltage-gated Ca(2+) channels, which similar to other voltage-dependent Ca(2+) channels trigger and control neurotransmitter release. The murine retina has the great advantage that the effect of gene inactivation for Ni(2+) -sensitive Ca(2+) channels can be analysed to prove or disprove that any of these Ca(2+) channels is involved in retinal signalling.
Methods: Superfused retinas from different murine genotypes lacking either one or both highly Ni(2+) -sensitive voltage-gated Ca(2+) channels were used to record their ex vivo ERGs.
Results: The isolated retinas from mice lacking Ca(v)2.3 R-type or Ca(v)3.2 T-type or both voltage-gated Ca(2+) channels were superfused with a NiCl(2) (15 μm) containing nutrient solution. The change in the b-wave amplitude and implicit time, caused by NiCl(2), was calculated as a difference spectrum and compared to data from control animals. From the results, it can be deduced that Ca(v)2.3 contributes rather to a later component in the b-wave response, while in the absence of Ca(v)3.2 the gain of Ni(2+) -mediated increase in the b-wave amplitude is significantly increased, probably due to a loss of reciprocal inhibition to photoreceptors. Thus, each of the Ni(2+)-sensitive Ca(2+) channels contributes to specific features of the b-wave response.
Conclusion: Both high-affinity Ni(2+)-sensitive Ca(2+) channels contribute to transretinal signalling. Based on the results from the double knockout mice, additional targets for NiCl(2) must contribute to transretinal signalling, which will be most important for the structurally similar physiologically more important heavy metal cation Zn(2+).
Details
- Title: Subtitle
- Two separate Ni 2+ ‐sensitive voltage‐gated Ca 2+ channels modulate transretinal signalling in the isolated murine retina
- Creators
- Maged Alnawaiseh - Institute of Neurophysiology, University of Cologne, Koeln, GermanyWalid Albanna - Institute of Neurophysiology, University of Cologne, Koeln, GermanyChien‐Chang Chen - Molecular Physiology and Biophysics, The University of Iowa College of Medicine, Iowa City, Iowa, USAKevin P Campbell - Departments of Molecular Physiology and Biophysics, Neurology, and Internal Medicine, and the Howard Hughes Medical Institute, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa, USAJürgen Hescheler - Institute of Neurophysiology, University of Cologne, Koeln, Germany, Center of Molecular Medicine Cologne (CMMC), University of Cologne, Koeln, GermanyMatthias Lüke - Institute of Neurophysiology, University of Cologne, Koeln, Germany, University Eye Hospital, University of Lübeck, Ratzeburger Allee 160, Lübeck, GermanyToni Schneider - Institute of Neurophysiology, University of Cologne, Koeln, Germany, Departments of Molecular Physiology and Biophysics, Neurology, and Internal Medicine, and the Howard Hughes Medical Institute, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa, USA
- Resource Type
- Journal article
- Publication Details
- Acta ophthalmologica (Oxford, England), Vol.89(7), pp.e579-e590
- DOI
- 10.1111/j.1755-3768.2011.02167.x
- PMID
- 21883984
- NLM abbreviation
- Acta Ophthalmol
- ISSN
- 1755-375X
- eISSN
- 1755-3768
- Language
- English
- Date published
- 11/2011
- Academic Unit
- Neurology; Molecular Physiology and Biophysics; Iowa Neuroscience Institute
- Record Identifier
- 9984068386102771
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