Pittsburgh Center for Pain Research, Deparment of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Exp Neurol. 2011 Aug;230(2):258-72. doi: 10.1016/j.expneurol.2011.05.004. Epub 2011 May 8.
Glutamate is the main excitatory neurotransmitter in the nervous system, including in primary afferent neurons. However, to date a glutamatergic phenotype of autonomic neurons has not been described. Therefore, we explored the expression of vesicular glutamate transporter (VGLUT) types 1, 2 and 3 in lumbar sympathetic chain (LSC) and major pelvic ganglion (MPG) of naïve BALB/C mice, as well as after pelvic nerve axotomy (PNA), using immunohistochemistry and in situ hybridization. Colocalization with activating transcription factor-3 (ATF-3), tyrosine hydroxylase (TH), vesicular acetylcholine transporter (VAChT) and calcitonin gene-related peptide was also examined. Sham-PNA, sciatic nerve axotomy (SNA) or naïve mice were included. In naïve mice, VGLUT(2)-like immunoreactivity (LI) was only detected in fibers and varicosities in LSC and MPG; no ATF-3-immunoreactive (IR) neurons were visible. In contrast, PNA induced upregulation of VGLUT(2) protein and transcript, as well as of ATF-3-LI in subpopulations of LSC neurons. Interestingly, VGLUT(2)-IR LSC neurons coexpressed ATF-3, and often lacked the noradrenergic marker TH. SNA only increased VGLUT(2) protein and transcript in scattered LSC neurons. Neither PNA nor SNA upregulated VGLUT(2) in MPG neurons. We also found perineuronal baskets immunoreactive either for VGLUT(2) or the acetylcholinergic marker VAChT in non-PNA MPGs, usually around TH-IR neurons. VGLUT(1)-LI was restricted to some varicosities in MPGs, was absent in LSCs, and remained largely unaffected by PNA or SNA. This was confirmed by the lack of expression of VGLUT(1) or VGLUT(3) mRNAs in LSCs, even after PNA or SNA. Taken together, axotomy of visceral and non-visceral nerves results in a glutamatergic phenotype of some LSC neurons. In addition, we show previously non-described MPG perineuronal glutamatergic baskets.
谷氨酸是神经系统中的主要兴奋性神经递质,包括初级传入神经元。然而,到目前为止,自主神经元的谷氨酸能表型尚未被描述。因此,我们使用免疫组织化学和原位杂交技术,在未接受神经损伤的 BALB/C 小鼠的腰交感神经链(LSC)和主要盆神经节(MPG)中,以及在盆神经切断术后(PNA),探索了囊泡谷氨酸转运体(VGLUT)1、2 和 3 的表达。还检查了与激活转录因子-3(ATF-3)、酪氨酸羟化酶(TH)、囊泡乙酰胆碱转运体(VAChT)和降钙素基因相关肽的共定位。还包括 Sham-PNA、坐骨神经切断术(SNA)或未接受神经损伤的小鼠。在未接受神经损伤的小鼠中,仅在 LSC 和 MPG 的纤维和小泡中检测到 VGLUT(2)样免疫反应性(LI);看不见 ATF-3-免疫反应性(IR)神经元。相比之下,PNA 诱导了 LSC 神经元亚群中 VGLUT(2)蛋白和转录物以及 ATF-3-LI 的上调。有趣的是,VGLUT(2)-IR LSC 神经元共表达 ATF-3,并且通常缺乏去甲肾上腺素能标志物 TH。SNA 仅增加了散在的 LSC 神经元中的 VGLUT(2)蛋白和转录物。PNA 或 SNA 均未上调 MPG 神经元中的 VGLUT(2)。我们还发现,在非 PNA 的 MPG 中,有些围绕 TH-IR 神经元的神经周间隙篮状结构,对 VGLUT(2)或乙酰胆碱能标记物 VAChT 呈免疫反应性。VGLUT(1)-LI 仅限于 MPG 中的一些小泡,在 LSC 中不存在,并且在 PNA 或 SNA 后基本不受影响。这通过 LSC 中 VGLUT(1)或 VGLUT(3)mRNA 的缺乏表达得到证实,即使在 PNA 或 SNA 后也是如此。总之,内脏和非内脏神经的切断导致一些 LSC 神经元的谷氨酸能表型。此外,我们还展示了以前未描述的 MPG 神经周间隙谷氨酸能篮状结构。