Persistence of intact retinal ganglion cell terminals after axonal transport loss in the DBA/2J mouse model of glaucoma.

Title

Persistence of intact retinal ganglion cell terminals after axonal transport loss in the DBA/2J mouse model of glaucoma.

Creator

Smith Matthew A; Xia Christina Z; Dengler-Crish Christine M; Fening Kelly M; Inman Denise M; Schofield Brett R; Crish Samuel D

Publisher

The Journal of comparative neurology

Date

2016
2016-12

Description

Axonal transport defects are an early pathology occurring within the retinofugal projection of the DBA/2J mouse model of glaucoma. Retinal ganglion cell (RGC) axons and terminals are detectable after transport is affected, yet little is known about the condition of these structures. We examined the ultrastructure of the glaucomatous superior colliculus (SC) with three-dimensional serial block-face scanning electron microscopy to determine the distribution and morphology of retinal terminals in aged mice exhibiting varying levels of axonal transport integrity. After initial axonal transport failure, retinal terminal densities did not vary compared with either transport-intact or control tissue. Although retinal terminals lacked overt signs of neurodegeneration, transport-intact areas of glaucomatous SC exhibited larger retinal terminals and associated mitochondria. This likely indicates increased oxidative capacity and may be a compensatory response to the stressors that this projection is experiencing. Areas devoid of transported tracer label showed reduced mitochondrial volumes as well as decreased active zone number and surface area, suggesting that oxidative capacity and synapse strength are reduced as disease progresses but before degeneration of the synapse. Mitochondrial volume was a strong predictor of bouton size independent of pathology. These findings indicate that RGC axons retain connectivity after losing function early in the disease process, creating an important therapeutic opportunity for protection or restoration of vision in glaucoma. J. Comp. Neurol. 524:3503-3517, 2016. (c) 2016 Wiley Periodicals, Inc.

Subject

*Axonal Transport/physiology; *bouton; *mitochondria; *neurodegeneration; *retinal; *RRID:IMSRJAX:000671; *RRID:IMSRJAX:007048; *RRID:SCR002716; *RRID:SCR002865; *superior colliculus; *synapse; Animal; Animals; Disease Models; Electron; Glaucoma/metabolism/*pathology; Imaging; Inbred DBA; Mice; Microscopy; Mitochondria/pathology; Neuroanatomical Tract-Tracing Techniques; Regression Analysis; Retinal Ganglion Cells/metabolism/*pathology; Scanning; Superior Colliculi/metabolism/*pathology; Synapses/metabolism/*pathology; Three-Dimensional; Visual Pathways/metabolism/pathology

Identifier

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

3503–3517

Issue

17

Volume

524

Citation

Smith Matthew A; Xia Christina Z; Dengler-Crish Christine M; Fening Kelly M; Inman Denise M; Schofield Brett R; Crish Samuel D, “Persistence of intact retinal ganglion cell terminals after axonal transport loss in the DBA/2J mouse model of glaucoma.,” NEOMED Bibliography Database, accessed September 22, 2021, https://neomed.omeka.net/items/show/2987.

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