Gong Suzhen, DeCuypere Michael, Zhao Yu, LeDoux Mark S
The University of Tennessee Health Science Center, Departments of Neurology and Anatomy and Neurobiology, 855 Monroe Avenue, Suite 415, Memphis, TN 38163, USA.
Brain Res. 2005 Jun 21;1047(2):177-93. doi: 10.1016/j.brainres.2005.04.045.
Cerebral cortical neural networks associated with eyelid movement play a critical role in facial animation, contribute to the regulation of blink frequency, and help prevent ocular injury. Eyelid closure depends, in part, on motoneurons that innervate the orbicularis oculi (OO) muscles. In this study, OO motoneuron cortical afferents were identified in rhesus monkeys with rabies virus, a retrograde transneuronal tracer. Virus was injected into the right OO muscle and immunohistochemically localized after 4-6 day transport intervals. Labeled motoneurons were limited to dorsal portions of the ipsilateral facial motor nucleus. After 4- and 4.5-day transport intervals, most labeled cortical neurons were localized to ventrolateral premotor (LPMCv), dorsolateral premotor (LPMCd), and motor (M1) cortices. Labeled neurons were more sparsely distributed in supplementary (M2), caudal (M4), and rostral (M3) cingulate motor cortices; the frontal eye fields (FEF); pre-supplementary motor cortex (pre-SMA); somatosensory cortices (areas 3a, 3b, and 1); and prefrontal cortex. At longer transport intervals (5-6 days), labeled neurons increased substantially in LPMCv, LPMCd, M2, M3, M4, pre-SMA, and FEF. Concentrations of labeled neurons also appeared in cortices along the lateral fissure and intraparietal sulcus. Overall, the densest collection of labeled neurons was localized to the caudal junction of LPMCd and LPMCv with M1. Rostral M3 was another focus of OO premotor neurons. Labeled neurons were distributed bilaterally in all motor cortical areas with a modest contralateral predominance for M2, LPMC, and M1. Thus, the cortical control of OO motor activity is distributed bilaterally among multiple motor areas.
与眼睑运动相关的大脑皮质神经网络在面部表情中起关键作用，有助于调节眨眼频率，并有助于预防眼部损伤。眼睑闭合部分取决于支配眼轮匝肌（OO）的运动神经元。在本研究中，利用狂犬病病毒（一种逆行跨神经元示踪剂）在恒河猴中鉴定了OO运动神经元的皮质传入神经。将病毒注入右侧OO肌肉，并在4 - 6天的运输间隔后进行免疫组织化学定位。标记的运动神经元仅限于同侧面神经运动核的背侧部分。在4天和4.5天的运输间隔后，大多数标记的皮质神经元定位于腹外侧运动前区（LPMCv）、背外侧运动前区（LPMCd）和运动皮质（M1）。标记的神经元在辅助运动皮质（M2）、尾侧运动皮质（M4）和吻侧运动皮质（M3）、额叶眼区（FEF）、前辅助运动皮质（pre - SMA）、躯体感觉皮质（3a区、3b区和1区）以及前额叶皮质中分布较为稀疏。在更长的运输间隔（5 - 6天）时，LPMCv、LPMCd、M2、M3、M4、pre - SMA和FEF中的标记神经元显著增加。标记神经元的集中区域也出现在沿外侧裂和顶内沟的皮质中。总体而言，标记神经元最密集的区域定位于LPMCd和LPMCv与M1的尾侧交界处。吻侧M3是OO运动前神经元的另一个集中区域。标记神经元在所有运动皮质区域双侧分布，M2、LPMC和M1中对侧的优势稍明显。因此，OO运动活动的皮质控制在多个运动区域双侧分布。
