Figure 4

Effects of chronic glaucoma on retinal mIPSCs and GAD65/67 protein expression. (A) Representative traces of voltage clamp recordings of GABAergic mIPSCs in the presence of TTX (1 μM) in control and glaucomatous retinas. The baseline frequency of the mIPSCs is markedly reduced in the glaucomatous retina compared with the control retina. (B–E) Histograms showing the mean frequency, amplitude, decay time, and rise time of the mIPSCs for control and glaucomatous retinas. The mIPSC frequency (decreased by 68%, n = 4, **p < 0.01) and decay time (increased by 37%, n = 5, *p < 0.05) are significantly different between the control and glaucomatous retinas. (F) Western blotting of GAD65/67 protein expression in glaucomatous and control retinal homogenates. The full-length blots are presented in Supplementary Figure S1. (G) Densitometric analysis of GAD65/67, confirming the downregulation of GAD65/67 protein expression in the glaucomatous retina at 1 week (n = 4), 2 weeks (n = 4), and 3 weeks (n = 3) after inducing ocular hypertension. *p < 0.05 and **p < 0.01 (one-way analysis of variance). GAD65/67 expression was normalized to β-actin level and is shown relative to its expression in control retinas. The results in B–E and G are expressed as the mean ± SE. GAD, glutamic acid decarboxylase; OHT, ocular hypertension; w, week.