The elucidation of the onset organization of the trigeminal neuralgia using a trigeminal nerve damage animal.

口腔颌面部有皮肤和粘膜区，注射福尔马林对这两个不同区域的危害行为不同。在大鼠上唇皮下注射稀释福尔马林比在舌头皮下注射福尔马林更能诱发有害行为。当将福尔马林注射到嘴唇而不是舌头时，这种行为被预先给药的GABA_A受体拮抗剂bicuculline所抑制。c -纤维种群在数量和质量上的分布差异可能是造成其致害行为和药理学差异的原因。舌头在c -纤维范围内的初级传入神经元（三叉神经）比嘴唇皮肤少。三叉神经尾侧亚核（Vc）的I层分布有相当数量的P物质（SP）、神经激肽-1 （NK-1）神经元受体，III层分布较少。我们通过将SP结合核糖体失活毒素皂苷（SP- sap）预先注入大鼠大池，消除了这些携带nk -1的神经元。在这些sp - sap预处理的大鼠中，福尔马林诱导的攻击性行为减少，而在未处理的大鼠中，二胡兰减少了攻击性行为，而预施用二胡兰则增强了攻击性行为。这些结果表明，携带nk -1的神经元通过上升和下降的伤害促进环参与前伤害感知传感器，其中GABA起预知感知作用。

The orofacial region has skin and mucous region and the formalin injection into the two different region induces different nocifensive behavior. The subcutaneous injection of diluted formalin into the rat upper lip induced more nocifensive behaviour than into the tongue. The behavior was inhibited more by the preadministration of an antagonist of GABA_A receptor, bicuculline, when formalin was injected into the lip than into the tongue. The resultant differences of nocifensive behaviour and pharmacology could be caused by the differences in the quantitative and qualitative distribution of C-fiber population. The tongue has fewer primary afferent neurons (trigeminal nerve) in the range of C-fiber than the lip skin.Considerable number of neurons-bearing receptors of substance P (SP), neurokinin-1 (NK-1) are distributed in lamina I and less in lamina III of trigeminal subnucleus caudalis (Vc). We have eliminated these NK-1-bearing neurons by preadministration of SP conjugated with a ribosome-inactivating toxin, saporin (SP-Sap) into the rat cisterna magna. In these SP-Sap-pretreated rats, the formalin-induced nocifensive behaviour was reduced and the preadministration of bicuculline enhanced the nocifensive behaviour, when bicuculline reduced it in the naive rats. These results show that NK-1-bearing neurons are involved in pro-nociceptive transducer through ascending and descending nociceptive facilitating loop, where GABA acts as prpnociceptive.