虎蝾螈视网膜切片中双极细胞的γ-氨基丁酸转运体介导电流

gamma-aminobutyric acid transporter-mediated current from bipolar cells in tiger salamander retinal slices.

作者信息

Yang C Y

机构信息

Department of Neurobiology and Behavior, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.

出版信息

Vision Res. 1998 Sep;38(17):2521-6. doi: 10.1016/s0042-6989(98)00100-x.

DOI:10.1016/s0042-6989(98)00100-x

PMID:12116699

Abstract

About 10% of bipolar cells in salamander retina synthesize and take up gamma-aminobutyric acid (GABA), and may use GABA as a neurotransmitter. As GABA uptake is electrogenic, bipolar cells expressing GABA transporters (GATs) should give transport current (IGAT) to extracellular GABA. Using whole-cell patch recording, 28 bipolar cells responded to 30-200 microM GABA puffed to the axon terminals with a picrotoxin (PTX)-sensitive chloride current (ICI) only. Another three bipolar cells had, in addition to ICI, a PTX-resistant, sodium-dependent current that was completely and reversibly blocked by NO-711, an IGAT inhibitor, indicating that this component was an IGAT. This finding provides further support for a subset of GABAergic bipolar cells in the salamander retina.

摘要

蝾螈视网膜中约10%的双极细胞合成并摄取γ-氨基丁酸（GABA），且可能将GABA用作神经递质。由于GABA摄取是生电的，表达GABA转运体（GATs）的双极细胞应向细胞外GABA提供转运电流（IGAT）。使用全细胞膜片钳记录，28个双极细胞仅对吹送至轴突末端的30 - 200微摩尔GABA产生对印防己毒素（PTX）敏感的氯离子电流（ICI）。另外三个双极细胞除了有ICI外，还有一种对PTX耐药、依赖钠的电流，该电流被IGAT抑制剂NO - 711完全且可逆地阻断，表明该成分是IGAT。这一发现为蝾螈视网膜中一部分GABA能双极细胞提供了进一步的支持。