Abstract
Purpose: :
To evaluate retinal ganglion cell morphology after induction of experimental glaucoma and optic nerve crush in mice.
Methods: :
Transgenic mice that express yellow fluorescent protein (YFP) in a small subset of RGCs were used (strain B6.Cg-Tg(Thy1-YFPH)2Jrs/J, The Jackson Laboratory, Bar Harbor, Maine). Experimental glaucoma was induced using bead injection and the animals were sacrificed one week after the initial bead injection. The optic nerve crush group was sacrificed 4 days after the surgery. Individual YFP-positive cells were imaged using confocal microscopy. The morphology of RGCs was analysed using our new method (Kalesnykas et al., abstract submitted, ARVO 2011) with MetaMorph Offline version 7.7.0.0 image analysis software (Molecular Devices, Downington, PA). Ultrathin cross-sections of the optic nerves from the optic nerve crush group were evaluated.
Results: :
RGCs from bead glaucoma eyes had lower neurite outgrowth and Sholl analysis’ values than RGCs from contralateral eyes without statistical significance. In contrast, the parameters of the neurite outgrowth and Sholl analysis were significantly lower in the optic nerve crush eyes when compared to contralateral controls.
Conclusions: :
A 4-day optic nerve crush causes significant morphological alterations in RGCs as measured by neurite outgrowth and dendritic tree complexity. Conversely, 1-week bead glaucoma caused only mild RGC morphological alterations.
Keywords: ganglion cells • degenerations/dystrophies • optic nerve