Axons of retinal ganglion cells are insulted in the optic nerve early in DBA/2J glaucoma

GR Howell, RT Libby, TC Jakobs, RS Smith… - The Journal of cell …, 2007 - rupress.org
GR Howell, RT Libby, TC Jakobs, RS Smith, FC Phalan, JW Barter, JM Barbay, JK Marchant…
The Journal of cell biology, 2007rupress.org
Here, we use a mouse model (DBA/2J) to readdress the location of insult (s) to retinal
ganglion cells (RGCs) in glaucoma. We localize an early sign of axon damage to an
astrocyte-rich region of the optic nerve just posterior to the retina, analogous to the lamina
cribrosa. In this region, a network of astrocytes associates intimately with RGC axons. Using
BAX-deficient DBA/2J mice, which retain all of their RGCs, we provide experimental
evidence for an insult within or very close to the lamina in the optic nerve. We show that …
Here, we use a mouse model (DBA/2J) to readdress the location of insult(s) to retinal ganglion cells (RGCs) in glaucoma. We localize an early sign of axon damage to an astrocyte-rich region of the optic nerve just posterior to the retina, analogous to the lamina cribrosa. In this region, a network of astrocytes associates intimately with RGC axons. Using BAX-deficient DBA/2J mice, which retain all of their RGCs, we provide experimental evidence for an insult within or very close to the lamina in the optic nerve. We show that proximal axon segments attached to their cell bodies survive to the proximity of the lamina. In contrast, axon segments in the lamina and behind the eye degenerate. Finally, the Wlds allele, which is known to protect against insults to axons, strongly protects against DBA/2J glaucoma and preserves RGC activity as measured by pattern electroretinography. These experiments provide strong evidence for a local insult to axons in the optic nerve.
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