Plasmalemmal and vesicular γ-aminobutyric acid transporter expression in the developing mouse retina

• Published in: Journal of comparative neurology (1911) 2009-01, Vol.512 (1), p.6-26
• Main Authors: Guo, Chenying, Stella Jr, Salvatore L., Hirano, Arlene A., Brecha, Nicholas C.
• Format: Article
• Language: English
• Subjects: Age Factors; amacrine cells; Animals; Animals, Newborn; Biomarkers - metabolism; Brain - metabolism; Cell Membrane - metabolism; Female; GABA Plasma Membrane Transport Proteins - metabolism; GAT; horizontal cells; Male; Mice; Mice, Inbred C57BL; retina; Retina - cytology; Retina - growth & development; Retina - metabolism; Vesicular Inhibitory Amino Acid Transport Proteins - metabolism; VGAT; visual system
• ISSN: 0021-9967; 1096-9861
• DOI: 10.1002/cne.21846

Plasmalemmal and vesicular γ‐aminobutyric acid (GABA) transporters influence neurotransmission by regulating high‐affinity GABA uptake and GABA release into the synaptic cleft and extracellular space. Postnatal expression of the plasmalemmal GABA transporter‐1 (GAT‐1), GAT‐3, and the vesicular GABA/glycine transporter (VGAT) were evaluated in the developing mouse retina by using immunohistochemistry with affinity‐purified antibodies. Weak transporter immunoreactivity was observed in the inner retina at postnatal day 0 (P0). GAT‐1 immunostaining at P0 and at older ages was in amacrine and displaced amacrine cells in the inner nuclear layer (INL) and ganglion cell layer (GCL), respectively, and in their processes in the inner plexiform layer (IPL). At P10, weak GAT‐1 immunostaining was in Müller cell processes. GAT‐3 immunostaining at P0 and older ages was in amacrine cells and their processes, as well as in Müller cells and their processes that extended radially across the retina. At P10, Müller cell somata were observed in the middle of the INL. VGAT immunostaining was present at P0 and older ages in amacrine cells in the INL as well as processes in the IPL. At P5, weak VGAT immunostaining was also observed in horizontal cell somata and processes. By P15, the GAT and VGAT immunostaining patterns appear similar to the adult immunostaining patterns; they reached adult levels by about P20. These findings demonstrate that GABA uptake and release are initially established in the inner retina during the first postnatal week and that these systems subsequently mature in the outer retina during the second postnatal week. J. Comp. Neurol. 512:6–26, 2009. Published 2008 Wiley‐Liss, Inc.