Expression of P2X7 receptor immunoreactivity in distinct subsets of synaptic terminals in the ventral horn of rat lumbar spinal cord
Expression of P2X7 receptor immunoreactivity in distinct subsets of synaptic terminals in the ventral horn of rat lumbar spinal cord
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DOI：
10.1016/j.brainres.2004.06.014
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发表时间：
2004-09-10
期刊：
影响因子：
2.9
通讯作者：
Fyffe, REW
中科院分区：
文献类型：
--
作者：
Deng, ZH;Fyffe, REW
5' -三磷酸腺苷（ATP）可通过激活突触前和/或突触后P2 X（P2 X（1）-P2 X（7））离子型受体来调节CNS中的神经传递。P2 X（7）嘌呤能受体已被证明调节海马兴奋性突触的递质释放，并已被定位于几个CNS区域的多巴胺能终末。在此，我们分析了P2 X（7）-免疫反应性（IR）在脊髓腹角的多种化学鉴定的兴奋性和抑制性突触前末梢中的存在，包括胆碱能C-末梢和运动轴突侧支以及表达VGLUT 1-或VGLUT 2-IR的谷氨酸能末梢，而P2 X（7）-IR和VGLUT 2-IR广泛共定位（类似于94%），与VGLUT 1、单胺能或抑制性末端几乎没有共定位（小于或等于15%）。此外，虽然P2 X（7）-IR存在于神经肌肉接头（NMJ）的运动轴突终末，但只有约32%的腹角运动轴突终末显示P2 X（7）-IR;与此相反，几乎所有接触运动神经元的大型胆碱能C末端（91%）都表达P2 X（7）-结果表明，参与脊髓运动控制回路的不同突触群可能受到P2 X（7）受体激活的差异调节。(C)2004 Elsevier B. V.保留所有权利。
Adenosine 5' -triphosphate (ATP) may regulate neurotransmission in the CNS by activating presynaptic and/or postsynaptic P2X (P2X(1)- P2X(7)) ionotropic receptors. P2X(7) purinergic receptors have been shown to modulate transmitter release at excitatory synapses in the hippocampus and have been localized in glutamatergic terminals in several CNS regions. Here, we analyze P2X(7)-immunoreactivity (IR) in a variety of immunohistochemically identified excitatory and inhibitory presynaptic terminals in the spinal cord ventral horn, including cholinergic C-terminals and motor axon collaterals and glutamatergic terminals that express VGLUT1- or VGLUT2-IR. Whereas there is widespread colocalization of P2X(7)-IR and VGLUT2-IR ( similar to 94%), there is little colocalization (less than or equal to 15%) with VGLUT1, monoaminergic or inhibitory terminals. Furthermore, although P2X(7)-IR is present in motor axon terininals at the neuromuscular junction (NMJ), only about 32% of the presumed motor axon terminals in the ventral horn exhibit P2X(7)-IR; in contrast, almost all large cholinergic C-terminals contacting motoneurons (91%) express P2X(7)-IR. The results suggest that distinct populations of synapses involved in spinal cord motor control circuits may be differentially regulated by the activation of P2X(7) receptors. (C) 2004 Elsevier B.V. All rights reserved.