Universität zu Köln

Alnawaiseh, Maged, Albanna, Walid ORCID: 0000-0001-9986-8739, Chen, Chien-Chang ORCID: 0000-0001-8850-4278, Campbell, Kevin P., Hescheler, Juergen, Lueke, Matthias and Schneider, Toni (2011). Two separate Ni2+-sensitive voltage-gated Ca2+ channels modulate transretinal signalling in the isolated murine retina. Acta Ophthalmol., 89 (7). S. E579 - 12. HOBOKEN: WILEY. ISSN 1755-3768

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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 NiCl2-sensitive component was attributed to reciprocal signalling by pharmacoresistant R-type voltage-gated Ca2+ channels, which similar to other voltage-dependent Ca2+ channels trigger and control neurotransmitter release. The murine retina has the great advantage that the effect of gene inactivation for Ni2+-sensitive Ca2+ channels can be analysed to prove or disprove that any of these Ca2+ channels is involved in retinal signalling. Methods: Superfused retinas from different murine genotypes lacking either one or both highly Ni2+-sensitive voltage-gated Ca2+ 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 Ca2+ channels were superfused with a NiCl2 (15 mu m) containing nutrient solution. The change in the b-wave amplitude and implicit time, caused by NiCl2, 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 Ni2+-mediated increase in the b-wave amplitude is significantly increased, probably due to a loss of reciprocal inhibition to photoreceptors. Thus, each of the Ni2+-sensitive Ca2+ channels contributes to specific features of the b-wave response. Conclusion: Both high-affinity Ni2+-sensitive Ca2+ channels contribute to transretinal signalling. Based on the results from the double knockout mice, additional targets for NiCl2 must contribute to transretinal signalling, which will be most important for the structurally similar physiologically more important heavy metal cation Zn2+.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Alnawaiseh, Maged UNSPECIFIED UNSPECIFIED UNSPECIFIED Albanna, Walid UNSPECIFIED orcid.org/0000-0001-9986-8739 UNSPECIFIED Chen, Chien-Chang UNSPECIFIED orcid.org/0000-0001-8850-4278 UNSPECIFIED Campbell, Kevin P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hescheler, Juergen UNSPECIFIED UNSPECIFIED UNSPECIFIED Lueke, Matthias UNSPECIFIED UNSPECIFIED UNSPECIFIED Schneider, Toni UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-486504
DOI:	10.1111/j.1755-3768.2011.02167.x
Journal or Publication Title:	Acta Ophthalmol.
Volume:	89
Number:	7
Page Range:	S. E579 - 12
Date:	2011
Publisher:	WILEY
Place of Publication:	HOBOKEN
ISSN:	1755-3768
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language ERG B-WAVE; SUPERFUSED VERTEBRATE RETINA; STATIONARY NIGHT BLINDNESS; CALCIUM-CHANNEL; RAT RETINA; BIPOLAR CELLS; NEUROTRANSMITTER RELEASE; DIFFERENTIAL EXPRESSION; RIBBON SYNAPSES; BOVINE RETINA Multiple languages Ophthalmology Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/48650