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Suppression of γ-aminobutyric acid transporter current by activation of ionotropic glutamate receptors on retinal horizontal cells

JIANG Xiao-Dong, SUN Yan, WANG Xu-Long, GONG Hai-Qing, LIANG Pei-Ji^*

School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China

Abstract

In the present study, the modulatory effect of AMPA receptors on γ-aminobutyric acid (GABA) transporter current was investigated on enzymatically isolated horizontal cells of carp retina. The GABA transporter current elicited by 1 mmol/L GABA was decreased immediately after pre-application of AMPA (30 μmol/L or 3 mmol/L) for 50 s. Application of 10 mmol/L BAPTA in intracellular solution inhibited the suppression effect of AMPA on GABA transporter current. The suppression effect induced by coapplication of 3 mmol/L AMPA and 3 mmol/L NMDA was similar to that of 3 mmol/L AMPA or 3 mmol/L NMDA alone. These results suggest that the activation of AMPA receptors inhibits GABA transporter-mediated current by affecting intracellular Ca2+ processes in the retinal horizontal cells, which is identical with the modulatory effect of NMDA receptors on GABA transporters.

Key words: GABA transporter; AMPA receptor; NMDA receptor; horizontal cell; retina

Received: 2009-03-18　　Accepted: 2009-05-05

Corresponding author: 梁培基　　E-mail: pjliang@sjtu.edu.cn

Citing This Article：

JIANG Xiao-Dong, SUN Yan, WANG Xu-Long, GONG Hai-Qing, LIANG Pei-Ji. Suppression of γ-aminobutyric acid transporter current by activation of ionotropic glutamate receptors on retinal horizontal cells. Acta Physiol Sin 2009; 61 (4): 299-304 (in Chinese with English abstract).