Mansour Yusra, Kulesza Randy
Department of Otolaryngology, Henry Ford Macomb Hospital, Detroit, MI, USA.
Department of Anatomy, Lake Erie College of Osteopathic Medicine, Erie, PA, USA.
Anat Cell Biol. 2023 Jun 30;56(2):271-275. doi: 10.5115/acb.22.223. Epub 2023 Feb 2.
The abducens nerve (AN; cranial nerve VI) exits the brainstem at the inferior pontine sulcus, pierces the dura of the posterior cranial fossa, passes through the cavernous sinus in close contact to the internal carotid artery (ICA) and traverses the superior orbital fissure to reach the orbit to innervate the lateral rectus muscle. At its exit from the brainstem, the AN includes only axons from lower motor neurons in the abducens nucleus. However, as the AN crosses the ICA it receives a number of branches from the internal carotid sympathetic plexus. The arrangement, neurochemical profile and function of these sympathetic axons running along the AN remain unresolved. Herein, we use gross dissection and microscopic study of hematoxylin and eosin-stained sections and sections with tyrosine hydroxylase immunolabeling. Our results suggest the AN receives multiple bundles of unmyelinated axons that use norepinephrine as a neurotransmitter consistent with postganglionic sympathetic axons.
展神经（AN；颅神经VI）于脑桥延髓沟下方离开脑干，穿过后颅窝硬脑膜，紧邻颈内动脉（ICA）穿过海绵窦，并经眶上裂进入眼眶，支配外直肌。展神经在离开脑干时，仅包含展神经核中低运动神经元发出的轴突。然而，当展神经跨过颈内动脉时，它会从颈内动脉交感神经丛接收一些分支。这些沿展神经走行的交感轴突的排列、神经化学特征及功能仍未明确。在此，我们采用大体解剖以及苏木精-伊红染色切片和酪氨酸羟化酶免疫标记切片的显微镜研究。我们的结果表明，展神经接收多束无髓鞘轴突，这些轴突以去甲肾上腺素作为神经递质，与节后交感轴突相符。
