FIGURE 4.

Aminoacid immunolabeling in the degus retina. (A,D,G,J) Glutamate, (B,E,H,K) Glutamine, (C,F,I,L) gamma-aminobutyric acid (GABA) Glutamate labeling was most different in juvenile retina (A) compared with young (D) and adults (G) where there was labeling throughout the retina. Glutamine in juvenile degus (B) was observed in the IPL and INL, while in young retina (E) glutamine expression was increased in areas corresponding to the location of Müller cells. High level of glutamine immunolabeling was seen in amacrine cells in the adult retina (H). GABA in juvenile (C) and in the young retina (F) was expressed in amacrine cells in the INL and immunolabeled sublayers in the IPL, while in adults (I) labeling increased in the INL and extended to labeling of the OPL. In the old adult, increased expression of glutamate (J), glutamine (K), and GABA (L) was observed. Quantification of the labeling in juvenile-adult ages is shown in (M–O). There were not enough silver intensified immunogold samples to quantify the old adult group. Scale bar on (I) = 20 μm and applies to (A–I). Scale bar on (L) = 20 μm and applies to (K,L). Statistical analysis was completed by one way ANOVA. Data are expressed as mean ± SEM (n = 4–5). Significant values are indicated with asterisks: ^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001.