Department of Neurosurgery, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis utca 6., H-6725 Szeged, Hungary.
Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary.
Cells. 2024 Apr 9;13(8):653. doi: 10.3390/cells13080653.
Subarachnoid hemorrhage (SAH) remains a major cause of cerebrovascular morbidity, eliciting severe headaches and vasospasms that have been shown to inversely correlate with vasodilator calcitonin gene-related peptide (CGRP) levels. Although dura mater trigeminal afferents are an important source of intracranial CGRP, little is known about the effects of SAH on these neurons in preclinical models. The present study evaluated changes in CGRP levels and expression in trigeminal primary afferents innervating the dura mater 72 h after experimentally induced SAH in adult rats. SAH, eliciting marked damage revealed by neurological examination, significantly reduced the density of CGRP-immunoreactive nerve fibers both in the dura mater and the trigeminal caudal nucleus in the medulla but did not affect the total dural nerve fiber density. SAH attenuated ex vivo dural CGRP release by ~40% and in the trigeminal ganglion, reduced both CGRP mRNA levels and the number of highly CGRP-immunoreactive cell bodies. In summary, we provide novel complementary evidence that SAH negatively affects the integrity of the CGRP-expressing rat trigeminal neurons. Reduced CGRP levels suggest likely impaired meningeal neurovascular functions contributing to SAH complications. Further studies are to be performed to reveal the importance of impaired CGRP synthesis and its consequences in central sensory processing.
蛛网膜下腔出血 (SAH) 仍然是脑血管病发病率的主要原因,引发剧烈头痛和血管痉挛,这些已被证明与血管扩张剂降钙素基因相关肽 (CGRP) 水平呈负相关。尽管硬脑膜三叉神经传入纤维是颅内 CGRP 的重要来源,但关于 SAH 对这些神经元在临床前模型中的影响知之甚少。本研究评估了成年大鼠实验性诱导 SAH 后 72 小时硬脑膜三叉神经初级传入纤维中 CGRP 水平和表达的变化。SAH 通过神经检查明显显示出损伤,显著降低了硬脑膜和延髓三叉神经尾核中 CGRP 免疫反应性神经纤维的密度,但不影响总硬脑膜神经纤维密度。SAH 使体外硬脑膜 CGRP 释放减少约 40%,并降低三叉神经节中 CGRP mRNA 水平和高度 CGRP 免疫反应性细胞体数量。总之,我们提供了新的补充证据,表明 SAH 会损害 CGRP 表达的大鼠三叉神经神经元的完整性。CGRP 水平降低表明脑膜神经血管功能受损,可能导致 SAH 并发症。需要进一步研究以揭示 CGRP 合成受损及其对中枢感觉处理的后果的重要性。