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许多药理学研究表明，哺乳动物脊髓背角中的GABA受体亚型（GABAA和GABAB）参与介导脊髓初级传入末梢的突触前抑制。本研究应用细胞内记录技术探讨GABAB受体激活对背根神经节细胞膜电特性的作用。实验标本取自SD成年大鼠L4～6后根节和猫在体L6～7后根节。当灌流液加入GABAB受体激动剂baclofen时，后根节的98个细胞中，约58％的细胞无反应。部分A类和C类细胞的膜电位出现超极化（n＝37）和去极化（n＝14）反应。A传入（n＝71）和C传入（n＝27）激活的反应没有明显的差异。Baclofen引起的DRG细胞的去极化和超极化反应可被GABAS受体选择性拮抗剂saclofen阻断。一些对baclofen反应的细胞也可被GABAA受体激动剂muscimol去极化。在所记录的细胞中，baclofen对动作电位时程（APD50）没有明显的影响。上述结果提示，在部分细胞中，baclofen激活的GABAB受体介导细胞膜电位去极化和超级化反应。GABAA和GABAB这二种受体不仅在慢传速的Aδ和C类细胞中共存，同样也共存于快传速的Aα和Aβ的细胞膜上。
Numerous pharmacological studies have shown that the GABA receptor subtypes (GABAA and GABAB) in the dorsal horn of the spinal cord of mammals are involved in the presynaptic inhibition of the primary afferent endings of the spinal cord. In this study, intracellular recording technique was used to investigate the effect of GABAB receptor activation on the membrane electrical properties of DRG neurons. Experimental specimens were taken from SD rats L4 ~ 6 posterior root ganglion and cat in vivo L6 ~ 7 posterior root ganglion. When the perfusate was added to the baclofen, a GABAB receptor agonist, about 58% of the 98 cells in the DRG were unresponsive. Membrane potentials were hyperpolarised (n = 37) and depolarized (n = 14) in some of the A and C cell types. There was no significant difference in response to A-entry (n = 71) and C-entry (n = 27) activation. Baclofen-induced depolarization and hyperpolarization of DRG cells can be blocked by saclofen, a GABAS receptor selective antagonist. Some cells that respond to baclofen can also be depolarized by the muscarinic GABAA receptor agonist. In the recorded cells, baclofen had no significant effect on the action potential duration (APD50). The above results suggest that in some cells, baclofen-activated GABAB receptors mediate depolarization of cell membrane potential and hyper-responsiveness. The two GABAA and GABAB receptors coexist not only in slow-moving Aδ and C cells, but also in fast-propagating Aα and Aβ cell membranes.