Purchase this article with an account.
J. D. Dapper, S. D. Crish, D. J. Calkins; Gene Expression Changes in Response to Age in the Superior Colliculus of the DBA/2J Mouse. Invest. Ophthalmol. Vis. Sci. 2010;51(13):2154.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Deficits in axonal transport between retinal ganglion cells and the brain increase with age (> or = 8 months) in the DBA/2J mouse model of glaucoma. In response to retinal deprivation, targets in the brain will often activate mechanisms in order to preserve or regain normal function. To determine how the superior colliculus (SC) may respond to loss of input from the retina, we examined expression of genes for the neuronal activity marker c-fos, brain-derived neurotrophic factor (BDNF), and the astrocyte marker glial fibrillary acidic protein (GFAP) in the DBA/2J SC before and during active transport loss.
To compare expression before and during transport loss, we used mice aged 3 months and 8 months, respectively. The SC of C57, DBA/2J-Gpnmb+/SjJ (D2; a non-glaucomatous DBA/2J mouse strain), and DBA/2J mice were freshly micro-dissected. Total RNA was extracted using a modified Trizol protocol. After cDNA synthesis, gene expression was assessed using quantitative polymerase chain reaction (qPCR) with gene-specific Taqman probes.
Expression levels for the c-fos, BDNF, and GFAP genes were each lower in DBA/2J mice compared to D2 controls at both ages examined. Ratios of the average expression of DBA/2J compared to D2 mice were c-fos=0.204, BDNF= 0.021, and GFAP=0.390 at 3 months and c-fos=0.877, BDNF=0.199, and GFAP=0.691 at 8 months. Although DBA/2J expression levels were lower for each age compared to the D2, a greater increase was seen in DBA/2J in average gene expression levels from 3 months to 8 months. Fold expression change was 1.21 for c-fos, 1.37 for BDNF, and 1.39 for GFAP in the D2 SC and 5.17 for c-fos, 12.68 for BDNF, and 2.46 for GFAP in the DBA/2J SC.
Expression levels of c-fos, BDNF, and GFAP were reduced in DBA/2J SC compared to SC in the non-glaucomatous control D2 mice both before (3 months) and during (8 months) transport depletion. While lowered transcription of these genes in the DBA/2J compared to the D2 suggests early dysfunction, the increase in gene expression from 3 to 8 months may be a compensatory mechanism to preserve RGC function in the SC.
This PDF is available to Subscribers Only