Inhibition of gamma-aminobutyric acid receptor-gated chloride currents by noradrenaline in rat spiral ganglion neuron
10.3321/j.issn:1673-0860.2008.04.013
- VernacularTitle:去甲肾上腺素抑制大鼠耳蜗螺旋神经元γ氨基丁酸门控氯通道电流
- Author:
Ding-Jun ZHA
1
;
Tao XUE
;
Li QIAO
;
Lian-Jun LU
;
Ying LIN
;
Zhi-Ming WANG
;
Yun-Qing LI
;
Jian-Hua QIU
Author Information
1. 第四军医大学西京医院
- Keywords:
Norepinephrine;
Spiral ganglion;
Chloride channels;
Patch-clamp techniques
- From:
Chinese Journal of Otorhinolaryngology Head and Neck Surgery
2008;43(4):302-305
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the pharmacological modulatory properties of noradrenaline in the rat spiral ganglion neuron.Methods Nystain perforated patch recording technique under voltage-clamp conditions was used to record the modulatory effect of noradrenaline on the current evoked by gamma-amino butyric acid (GABA) in the spiral ganglion neuron.Results The reversal potential of the GABA response was about(-0.78±0.05)mV(n=8),which was almost identical to the theoretical Cl- equilibrium potential.At the holding potential of -50 mV,GABA evoked inward current (IGABA) over the concentration range of 0.3 to 1μmol/L The EC50 and Hill coefficient for GABA were (5.2±0.5)μmol/L and 1.03(n=26).The IGABA was suppressed by bicuculline,the selective GABA-A receptor antagonist,and the chloride currents evoked by GABA was inhibited by noradrenaline.Conclusions The result indicates that noradrenaline depressed GABA-A receptor-gated chloride currents,which may contribute to the modulatory effect of sympathetic system on auditory transmission.
