Bicuculline-resistant, Cl- dependent GABA response in the rat spinal dorsal horn

被引:10
作者
Park, JS
Higashi, H
Nagata, K
Yoshimura, M
机构
[1] Saga Med Sch, Dept Physiol, Saga 849, Japan
[2] Kurume Univ, Sch Med, Dept Physiol, Kurume, Fukuoka 830, Japan
[3] Kurume Univ, Sch Med, Dept Orthoped, Kurume, Fukuoka 830, Japan
关键词
GABA(C); bicuculline resistant; CACA; substantia gelatinosa; spinal cord; GABA receptor subunit;
D O I
10.1016/S0168-0102(99)00016-4
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Receptors for gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the mammalian central nervous system (CNS), have been divided into three subtypes. GABA(A) receptor is a ligand-gated chloride channel that is competitively antagonized by bicuculline, whereas GABA(B) receptor regulate Ca2+ or K+ channels through G proteins. Recently, GABA(C) receptor has been identified in mammalian and fish retina. Unlike GABA(A) receptors, the GABA(C) receptor is a bicuculline-resistant chloride channel that is selectively activated by cis-4-aminocrotonic acid (CACA), and antagonized by imidazole-4-acetic acid (I4AA) and to some extent by picrotoxin. We report here that bicuculline-resistant GABA responses mediated by chloride channels are also expressed in substantia gelatinosa (SG) neurons in the dorsal horn, which receive predominantly nociceptive inputs from periphery. The GABA responses are, however, not mimicked by CACA nor affected by I4AA, but abolished by picrotoxin. Moreover, these responses are modulated by benzodiazepines (flunitrazepam) and barbiturates (thiopental), although GABA(C) responses are not affected. Thus, the pharmacological characteristics of the GABA responses observed in SG neurons are distinct from those responses mediated by the known GABA receptors. These differences may reflect the presence of receptor subunits unique to SG neurons. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.
引用
收藏
页码:261 / 268
页数:8
相关论文
共 44 条
[31]   NOVEL GABA RESPONSES FROM ROD-DRIVEN RETINAL HORIZONTAL CELLS [J].
QIAN, HH ;
DOWLING, JE .
NATURE, 1993, 361 (6408) :162-164
[32]   THE CYTOARCHITECTONIC ORGANIZATION OF THE SPINAL CORD IN THE CAT [J].
REXED, B .
JOURNAL OF COMPARATIVE NEUROLOGY, 1952, 96 (03) :415-&
[33]   INTRATHECAL MIDAZOLAM FOR THE TREATMENT OF CHRONIC MECHANICAL LOW-BACK-PAIN - A CONTROLLED COMPARISON WITH EPIDURAL STEROID IN A PILOT-STUDY [J].
SERRAO, JM ;
MARKS, RL ;
MORLEY, SJ ;
GOODCHILD, CS .
PAIN, 1992, 48 (01) :5-12
[34]  
SHIMADA S, 1992, MOL PHARMACOL, V41, P683
[35]   GABA RECEPTOR MECHANISMS IN THE CENTRAL-NERVOUS-SYSTEM [J].
SIVILOTTI, L ;
NISTRI, A .
PROGRESS IN NEUROBIOLOGY, 1991, 36 (01) :35-92
[36]   Pharmacologically novel GABA receptor in human dorsal root ganglion neurons [J].
Valeyev, AY ;
Hackman, JC ;
Wood, PM ;
Davidoff, RA .
JOURNAL OF NEUROPHYSIOLOGY, 1996, 76 (05) :3555-3558
[37]   A NOVEL GAMMA-SUBUNIT OF THE GABA-A RECEPTOR IDENTIFIED USING THE POLYMERASE CHAIN-REACTION [J].
WILSONSHAW, D ;
ROBINSON, M ;
GAMBARANA, C ;
SIEGEL, RE ;
SIKELA, JM .
FEBS LETTERS, 1991, 284 (02) :211-215
[38]   DISTRIBUTION OF GABA(A) RECEPTOR SUBUNIT MESSENGER-RNAS IN RAT LUMBAR SPINAL-CORD [J].
WISDEN, W ;
GUNDLACH, AL ;
BARNARD, EA ;
SEEBURG, PH ;
HUNT, SP .
MOLECULAR BRAIN RESEARCH, 1991, 10 (02) :179-183
[39]  
WOODWARD RM, 1993, MOL PHARMACOL, V43, P609
[40]   A novel slow excitatory postsynaptic current in substantia gelatinosa neurons of the rat spinal cord in vitro [J].
Yajiri, Y ;
Yoshimura, M ;
Okamoto, M ;
Takahashi, H ;
Higashi, H .
NEUROSCIENCE, 1997, 76 (03) :673-688