scholarly journals Mild Intraocular Pressure Elevation in Mice Reveals Distinct Retinal Ganglion Cell Functional Thresholds and Pressure-Dependent Properties

2019 ◽  
Vol 39 (10) ◽  
pp. 1881-1891 ◽  
Author(s):  
Xiaofeng Tao ◽  
Jasdeep Sabharwal ◽  
Robert L. Seilheimer ◽  
Samuel M. Wu ◽  
Benjamin J. Frankfort
Keyword(s):  
Intraocular Pressure ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Retinal Ganglion ◽  
Pressure Elevation ◽  
Intraocular Pressure Elevation

scholarly journals Intraocular Pressure Elevation Compromises Retinal Ganglion Cell Light Adaptation

2020 ◽  
Vol 61 (12) ◽  
pp. 15
Author(s):  
Xiaofeng Tao ◽  
Jasdeep Sabharwal ◽  
Samuel M. Wu ◽  
Benjamin J. Frankfort
Keyword(s):  
Intraocular Pressure ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Light Adaptation ◽  
Retinal Ganglion ◽  
Pressure Elevation ◽  
Intraocular Pressure Elevation

scholarly journals Retinal ganglion cell dysfunction in mice following acute intraocular pressure is exacerbated by P2X7 receptor knockout

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Y. M. Wang ◽  
Vickie H. Y. Wong ◽  
Pei Ying Lee ◽  
Bang V. Bui ◽  
Stefanie Dudczig ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
P2x7 Receptor ◽  
Field Size ◽  
Multielectrode Arrays ◽  
Retinal Ganglion ◽  
Post Injury ◽  
Genetic Ablation ◽  
Iop Elevation

AbstractThere is increasing evidence for the vulnerability of specific retinal ganglion cell (RGC) types in those with glaucoma and in animal models. In addition, the P2X7-receptor (P2X7-R) has been suggested to contribute to RGC death following stimulation and elevated IOP, though its role in RGC dysfunction prior to death has not been examined. Therefore, we examined the effect of an acute, non-ischemic intraocular pressure (IOP) insult (50 mmHg for 30 min) on RGC function in wildtype mice and P2X7-R knockout (P2X7-KO) mice. We examined retinal function using electroretinogram recordings and individual RGC responses using multielectrode arrays, 3 days following acute IOP elevation. Immunohistochemistry was used to examine RGC cell death and P2X7-R expression in several RGC types. Acute intraocular pressure elevation produced pronounced dysfunction in RGCs; whilst other retinal neuronal responses showed lesser changes. Dysfunction at 3 days post-injury was not associated with RGC loss or changes in receptive field size. However, in wildtype animals, OFF-RGCs showed reduced spontaneous and light-elicited activity. In the P2X7-KO, both ON- and OFF-RGC light-elicited responses were reduced. Expression of P2X7-R in wildtype ON-RGC dendrites was higher than in other RGC types. In conclusion, OFF-RGCs were vulnerable to acute IOP elevation and their dysfunction was not rescued by genetic ablation of P2X7-R. Indeed, knockout of P2X7-R also caused ON-RGC dysfunction. These findings aid our understanding of how pressure affects RGC function and suggest treatments targeting the P2X7-R need to be carefully considered.

scholarly journals Neuroprotective and Anti-Inflammatory Effects of a Hydrophilic Saffron Extract in a Model of Glaucoma

2019 ◽  
Vol 20 (17) ◽  
pp. 4110 ◽  
Author(s):  
Jose A. Fernández-Albarral ◽  
Ana I. Ramírez ◽  
Rosa de Hoz ◽  
Nerea López-Villarín ◽  
Elena Salobrar-García ◽  
...  
Keyword(s):  
Cell Death ◽  
Intraocular Pressure ◽  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Retinal Ganglion Cell Death ◽  
Saffron Extract ◽  
Anti Inflammatory ◽  
Ganglion Cell Death

Glaucoma is a neurodegenerative disease characterized by the loss of retinal ganglion cells (RGCs). An increase in the intraocular pressure is the principal risk factor for such loss, but controlling this pressure does not always prevent glaucomatous damage. Activation of immune cells resident in the retina (microglia) may contribute to RGC death. Thus, a substance with anti-inflammatory activity may protect against RGC degeneration. This study investigated the neuroprotective and anti-inflammatory effects of a hydrophilic saffron extract standardized to 3% crocin content in a mouse model of unilateral, laser-induced ocular hypertension (OHT). Treatment with saffron extract decreased microglion numbers and morphological signs of their activation, including soma size and process retraction, both in OHT and in contralateral eyes. Saffron extract treatment also partially reversed OHT-induced down-regulation of P2RY12. In addition, the extract prevented retinal ganglion cell death in OHT eyes. Oral administration of saffron extract was able to decrease the neuroinflammation associated with increased intraocular pressure, preventing retinal ganglion cell death. Our findings indicate that saffron extract may exert a protective effect in glaucomatous pathology.

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