Artikel
Intrinsic choroidal neurons (ICN) in human: non-nitrergic subpopulation
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Nitrergic intrinsic choroidal neurons (ICN) innervate vascular and stromal non-vascular smooth muscle cells, hence influencing choroidal blood flow and choroidal thickness. Studies of ICN topography with different markers (NADPH-d: Bergua et al., 2003; neurofilament-staining: Trivino et al., 2002) revealed different ICN densities in temporal versus nasal quadrants. This suggested the existence of a significant non-nitrergic subpopulation. Therefore, the aim of ths study was to quantify subpopulations of ICN with different neuronal markers, as well as to search for an overall marker of ICN.
Methods
11 choroidal wholemounts from donor eyes (53-84 years of age; 1-16 hrs p.m.) were processed for immunohistochemical single and double stainings for the following markers: NADPH-d, cocktail of neurofilament 160/200kD (NF), protein-gene product 9.5 (PGP9.5), and neuronal nitric oxide synthase (nNOS), respectively. For documentation, light-, fluorescence- and confocal laserscanning microscopy were used.
Results
The combination of NADPH-d and PGP 9.5 revealed that about 6% of the total population of ICN were positive for PGP 9.5 only, without preferential topography. Double labelling with NF and nNOS revealed, that about 20% of the total population of ICN were positive for NF only and about 6% for nNOS only, respectively, again without topographical preference.
Conclusions
Our results show, that there is a hitherto unrecognized NF+ non-nitrergic subpopulation of ICN, the chemical nature and targets of which have to be further elucidated. Differences in ICN topography published up to now may indicate age or desease related alterations within the choroid.