COEXISTENCE OF GABAA AND GABAB RECEPTORS ON A-DELTA-PRIMARY AND C-PRIMARY AFFERENTS
COEXISTENCE OF GABAA AND GABAB RECEPTORS ON A-DELTA-PRIMARY AND C-PRIMARY AFFERENTS
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DOI：
10.1111/j.1476-5381.1984.tb10082.x
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发表时间：
1984-01-01
影响因子：
7.3
通讯作者：
SCHLICHTER, R
中科院分区：
文献类型：
--
作者：
DESARMENIEN, M;FELTZ, P;SCHLICHTER, R
在体外进行来自成年大鼠背根神经节神经元的细胞内记录，并且鉴定了A δ细胞膜上2种GABA受体的共存。和C初级传入。短暂应用GABA（10-6-10-2 M）引起剂量依赖性去极化和膜电导增加。该反应被蝇蕈醇、异古瓦辛、THIP [4，5，6，7-四氢异恶唑并[5，4 c]-吡啶-3-醇]和3-氨基丙磺酸（3 APS）模拟;它们被荷包牡丹碱和印防己毒素阻断。戊巴比妥可增加GABA诱导的去极化。灌注四乙基铵（TEA，7.5 mM）和细胞内注射Cs+暴露的Ca 2+成分的动作电位，这似乎是持久的平台去极化。这种动作电位在甲氧基维拉帕米（D 600，5 × 10 - 6）存在下缩短。10 ~（-6）~ 10 ~（-5）M）和不含Ca ~（2+）的培养基中培养。GABA（10 ~（-9）~ 10 ~（-5）M）长时间灌注（5-10 min）可缩短动作电位的Ca ~（2+）成分。巴氯芬（10-7-5 × 10 - 6）模拟了这种作用。10-6 M）和蝇蕈醇（5x. 10-7-10-5 M），并且不受荷包牡丹碱灌注（5 × 10 - 5 M）的影响。10-6-10-5 M）。异古瓦辛（2.5x. 10-5 M）对动作电位时程无影响。显然，2个GABA受体共存于慢传导初级传入的膜上：荷包牡丹碱敏感的GABAA受体介导去极化，荷包牡丹碱不敏感的GABAB受体缩短动作电位的Ca 2+成分。
Intracellular recordings from adult rat dorsal root ganglion neurons were performed in vitro and the coexistence of 2 GABA receptors on the membrane of identified A.delta. and C primary afferents was demonstrated. Transient applications of GABA (10-6-10-2 M) evoked dose-dependent depolarizations and increased membrane conductance. The responses were mimicked by muscimol, isoguvacine, THIP [4,5,6,7-tetrahydroisoxazolo[5,4 c]-pyridin-3-ol] and 3-amino-propane sulfonic acid (3 APS); they were blocked by bicuculline and picrotoxin. Pentobarbitone induced an increase of GABA-induced depolarizations. Perfusion of tetraethylammonium (TEA, 7.5 mM) and intracellular injection of Cs+ unmasked the Ca2+ component of action potentials, which appeared as long-lasting plateau depolarizations. Such action potentials were shortened in the presence of methoxyverapamil (D600, 5 .times. 10-6-10-5 M) and in a medium without Ca2+. Prolonged (5-10 min) perfusion of GABA (10-9-10-5 M) shortened the Ca2+ component of action potentials. This effect was mimicked by baclofen (10-7-5 .times. 10-6 M) and muscimol (5 .times. 10-7-10-5 M) and was not affected by bicuculline perfusion (5 .times. 10-6-10-5 M). Isoguvacine (2.5 .times. 10-5 M) did not affect action potential duration. Evidently 2 GABA receptors coexist on the membrane of slow conducting primary afferents: the bicuculline-sensitive GABAA receptor mediates depolarizations and the bicuculline-insensitive GABAB receptor shortens the Ca2+ component of action potentials.