Benarroch E E, Smithson I L, Low P A, Parisi J E
Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
Ann Neurol. 1998 Feb;43(2):156-63. doi: 10.1002/ana.410430205.
The ventrolateral portion of the intermediate reticular formation of the medulla (ventrolateral medulla, VLM), including the C1/A1 groups of catecholaminergic neurons, is thought to be involved in control of sympathetic cardiovascular outflow, cardiorespiratory interactions, and reflex control of vasopressin release. As all these functions are affected in patients with multiple systems atrophy (MSA) with autonomic failure, we sought to test the hypothesis that catecholaminergic (tyrosine hydroxylase [TH]-positive) neurons of the VLM are depleted in these patients. Medullas were obtained at autopsy from 4 patients with MSA with prominent autonomic failure and 5 patients with no neurological disease. Patients with MSA had laboratory evidence of severe adrenergic sudomotor and cardiovagal failure. Tissue was immersion fixed in 2% paraformaldehyde at 4 degrees C for 24 hours and cut into 1-cm blocks in the coronal plane from throughout the medulla. Serial 50-microm sections were collected and one section every 300 microm was stained for TH. There was a pronounced depletion of TH neurons in the rostral VLM in all cases of MSA. There was also significant reduction of TH neurons in the caudal VLM in 3 MSA patients compared with 3 control subjects. In 2 MSA cases and in 2 control subjects, the thoracic spinal cord was available for study. There was also depletion of TH fibers and sympathetic preganglionic neurons (SPNs) in the 2 MSA cases examined. Thus, depletion of catecholaminergic neurons in the VLM may provide a substrate for some of the autonomic and endocrine manifestations of MSA.
延髓中间网状结构的腹外侧部分（腹外侧延髓，VLM），包括儿茶酚胺能神经元的C1/A1组，被认为参与交感心血管输出、心肺相互作用以及血管加压素释放的反射控制。由于自主神经功能衰竭的多系统萎缩（MSA）患者的所有这些功能均受到影响，我们试图验证以下假设：这些患者的VLM中儿茶酚胺能（酪氨酸羟化酶[TH]阳性）神经元减少。从4例有明显自主神经功能衰竭的MSA患者和5例无神经系统疾病的患者尸检中获取延髓。MSA患者有严重肾上腺素能发汗运动和心血管迷走神经功能衰竭的实验室证据。组织在4℃下用2%多聚甲醛浸泡固定24小时，并在整个延髓的冠状平面切成1厘米的块。收集连续的50微米切片，每隔300微米取一片进行TH染色。所有MSA病例的延髓头端VLM中TH神经元均明显减少。与3名对照受试者相比，3例MSA患者的延髓尾端VLM中TH神经元也显著减少。在2例MSA病例和2名对照受试者中，可获取胸段脊髓用于研究。在所检查的2例MSA病例中，TH纤维和交感神经节前神经元（SPN）也减少。因此，VLM中儿茶酚胺能神经元的减少可能是MSA某些自主神经和内分泌表现的基础。
