Study of receptors, second messengers and DNA binding proteins on noxio usstimulation

本研究运用组织化学、原位杂交组织化学、免疫组织化学及免疫组织化学与逆行示踪技术相结合的方法，对氨基酸对三叉神经感觉系统的调节作用进行了论证。我们用ISH方法检测了大鼠三叉神经节(TG)γ-氨基丁酸(GABA)_A受体Gamma1和Gamma2亚单位mRNAs的表达。大多数TG细胞同时表达Gamma1和Gamma2。此外，用抗Gamma1亚基的抗血清在蛋白水平上证实了Gamma1亚基在初级感觉神经传入神经元中的表达。这些结果表明，初级感觉传入接受GABA能传入，可能是通过表达Gamma1和Gamma2亚单位的GABA_A受体进行轴突输入。我们证明，在三叉神经尾侧核(TNC)中，少数投射到丘脑的神经元被识别AMPA型受体的GluR1和GluR2/3亚单位的抗血清标记。然而，GABA_A受体的Gamma1和Gamma2亚基的表达表明，在TNC中有几个投射到丘脑的神经元通过至少包含Gamma1和/或Gamma2亚基的GABA_A受体接受GABA能输入。

This study aimed at a demonstration for regulation of trigeminal sensory system by amino acids with using some histochemical technics, in situ hybridization histochemistry (ISH), immunohistochemistry and combination method of immunohistochemistry and retrograde tracer technic. We examined the expression of gamma-aminobutyric acid (GABA)_A receptor gamma1 and gamma2 subunit mRNAs in the rat trigeminal ganglion (TG) by ISH.Most TG cells expressed both gamma1 and gamma2 mRNAs simultaneously. Furthermore, expression of the gamma1 subunit in the primary sensory afferents was confirmed at the protein level by immunohistochemistry using antiserum against the gamma1 subunit. These findings indicate that primary sensory afferents receive GABAergic input, probably axo-axonically via GABA_A receptors expressing gamma1 and gamma2 subunits. We demonstrated that a few neurons projecting to the thalamus in the TNC (trigeminal nucleus caudalis) were labeled by antiserum that recognizes GluR1 and GluR2/3 subunits of the AMPA type receptor. However, expression of the gamma1 and gamma2 subunits of the GABA_A receptors indicated that several neurons projecting to the thalamus in the TNC receive GABAergic inputs via a GABA_A receptor which at contains least gamma1 and/or gamma2 subunits.