Figure 1. Altered bodyweight was correlated with decreased retinal function and increased GFAP expression in leptin-deficient (ob/ob) mice. A: The ob/ob mice showed an approximate doubling in bodyweight (grams) at 90 postnatal days compared to the wild-type (wt) littermate controls (p<0.05, n=8). B, C: We observed no statistically significant changes in blood glucose (B) or glycated hemoglobin (HbA1c, C) levels in the ob/ob mice compared to the littermate wt control mice. D, E: No changes in outer nuclear layer (ONL) thickness were detected across the retina (B, n=5), with no difference between the superior and inferior retina observed (C, n=5). F–H: Functional studies showed a statistically significant decrease in a- (F) and b-wave (G) amplitudes in the ob/ob mice compared to the wt control mice. This difference was most noticeable at the highest stimulus intensity of 1.9 Log cd.s/m2 (H, n=3 wt, n=6 ob/ob). I: Photopic electroretinography (ERG; cones) showed a statistically significant difference in function between the wt control and ob/ob animals at 1.9 Log cd.s/m2 (F, n=6 wt, n=6 ob/ob). J: In the ob/ob mice compared to the wt control mice, a statistically significant increase was determined for the retinal stress marker Gfap (p<0.05, n=9), but no statistically significant change was detected for the retinal stress markers Cntf and Fgf2 (n=9). K, L: Immunohistochemistry for GFAP showed increased labeling (arrowheads) in the ganglion cell layer (GCL) and the inner plexiform layer (IPL) in the ob/ob retinas (K) compared to the wt control retinas (L). Statistical analysis was performed using a Student t test (A–D, I, J) and a two-way ANOVA with uncorrected Fisher’s least significant difference (LSD) post-test (F–H). * indicates a statistical significance and a p value of less than 0.05. INL, inner nuclear layer. Scale bars = 50 µm. Error bars are displayed as standard error of the mean (SEM).