丁苯酞对FALS模型鼠雄激素受体表达的影响

目的探讨丁苯酞(NBP)对家族性肌萎侧索硬化(FALS)模型hSOD1G93A转基因鼠雄激素受体表达的影响及机制。方法观察NBP干预后不同性别hSOD1G93A转基因小鼠的发病时间及生存期,应用免疫组化的方法观察hSOD1G93A转基因小鼠终末期脊髓前角神经元雄激素受体的表达结果 NBP组雄性hSOD1G93A转基因小鼠生存期为133.52±9.16与安慰剂组120.27±8.98相比,P=0.00;雌性的hSOD1G93A转基因小鼠生存期136.21±11.90与安慰剂组128.13±8.20相比,P=0.04。NBP组雄、雌性存活期相比,P=0.58。NBP组雄性hSOD1G93A转基因小鼠发病时间为110.22±9.19天与安慰剂组101.13±8.90天相比,P=0.00;雌性的hSOD1G93A转基因小鼠发病时间113.04±12.73天,与安慰剂组96.07±4.92天相比,P=0.00。NBP组雄、雌发病时间相比,P=0.46。免疫组化结果显示终末期NBP组SOD1G93A转基因小鼠AR阳性的运动神经元数目5.87±1.598与安慰剂组2.93±1.1、空白对照组3.00±1.134相比,P<0.05;雄:雌残存神经元数量相比为6.75±1.282:4.86±1.345,P=0.02。结论 NBP可以推迟hSOD1G93A转基因小鼠的发病时间,延长生存期,与性别无明显相关;NBP增加hSOD1G93A转基因小鼠脊髓前角运动神经元雄激素受体的表达。     

丁苯酞对肌萎缩侧索硬化模型小鼠的生存期脊髓前角运动神经元Nrf2及HO-1表达

目的探讨丁苯酞(NBP)对SOD1~(G93A)转基因小鼠的生存期及脊髓前角运动神经元Nrf2、HO-1表达的影响及机制。方法肌萎缩侧索硬化(ALS)模型SOD1~(G93A)转基因小鼠24只,随机分为NBP组(n=12雌雄各半)和安慰剂组(n=12雌雄各半)选同窝SOD1~(G93A)阴性小鼠作为阴性对照(n=12雌雄各半)。于6w龄起分别给予NBP组NBP 180mg·kg~(-1)·d~(-1),安慰剂组玉米油10mL·kg~(-1)·d~(-1)灌胃,至终末期取材。观察两组的发病时间及生存期。通过甲苯胺蓝染色比较终末期两组小鼠脊髓前角运动神经元数目,通过免疫组织化学染色、蛋白印迹法观察干预前后脊髓前角Nrf2、HO-1的分布、表达情况。结果相比安慰剂组,NBP组可推迟转基因小鼠的发病时间(P0.05)显著延长小鼠生存期(P0.01);终末期残存的脊髓前角运动神经元数量明显增加(P0.01)。免疫组织化学染色结果显示,与安慰剂组相比,NBP组Nrf2在胞质内具有较强的免疫反应性差异有统计学意义(P=0.004)。NBP组HO-1在胞质内具有较强的免疫反应性差异无统计学意义(P=0.275)。蛋白印迹结果显示,相比安慰剂组,NBP组Nrf、HO-1蛋白的表达均明显增加(P均0.05)。结论NBP可以推迟SOD1~(G93A)转基因小鼠的发病时间并显著延长生存期,增加细胞质内Nrf2、HO-1的表达。     

小胶质细胞在SOD1-G93A转基因小鼠腰髓中的变化

目的观察小胶质细胞在SOD1-G93A转基因小鼠不同时期腰髓中的变化,探讨小胶质细胞活化与肌萎缩侧索硬化(ALS)疾病进展的关系。方法以国际公认的SOD1-G93A转基因小鼠,应用免疫组化、激光共聚焦显微镜及Westernblot方法 ,分别观察SOD1-G93A转基因小鼠症状前期、症状期、终末期及其同窝对照腰髓小胶质细胞形态数量及特异性标记物表达的变化情况。结果 SOD1-G93A转基因小鼠腰髓在症状前期(60天)已出现小胶质细胞数量增多及特异性标记物CD11b表达升高,随病程进展,症状期小胶质细胞增多、活化显著,终末期达高峰。结论随SOD1-G93A转基因小鼠病程进展小胶质细胞增生明显,小胶质细胞的活化可能参与ALS运动神经元损伤。     

丁苯酞对SOD1~(G93A)转基因鼠脊髓Ferritin表达的影响

目的探讨丁苯酞对SOD1G 93A转基因鼠的神经保护作用及其可能的机制。方法选取SOD1G 93A阳性小鼠48只,随机分为丁苯酞组(发病早期及终末期)和安慰剂组(发病早期及终末期),每组12只,观察SOD1G 93A转基因鼠的发病时间和生存期,采用免疫组化和蛋白印迹的方法观察SOD1G 93A转基因鼠腰髓铁蛋白(Ferritin)表达。结果丁苯酞组的发病时间为118.0±2.5d,与安慰剂组的109.5±2.2d相比较,P<0.05;生存时间为138.6±2.3d,与安慰剂组的128.1±2.8d相比较,P<0.05;免疫组化显示:发病初期,安慰剂组Ferritin阳性细胞显示胞浆和胞膜周围均匀着色,丁苯酞组Ferritin仅胞膜周围着色,胞核和胞浆着色不明显;终末期,丁苯酞组与安慰剂组相比,二者的Ferritin在胞核和胞浆均有着色;蛋白印迹显示:发病初期,Ferritin在腰髓表达量的相对值,丁苯酞组为0.81±0.23,与安慰剂组的1.57±0.43相比较,P<0.05;终末期,丁苯酞组为1.45±0.45,与安慰剂组的1.73±0.36相比较,P>0.05。结论丁苯酞延迟ALS小鼠的发病时间并延长其生存期,丁苯酞延迟小鼠发病可能与调节铁代谢有关。     

P2Y12受体介导小胶质细胞在肌萎缩侧索硬化疾病中的作用

目的 探索分析P2Y12受体介导小胶质细胞在肌萎缩侧索硬化(ALS)疾病发生发展中的作用。方法 应用SOD1-G93A转基因小鼠,通过转棒实验、Western blot方法及免疫荧光双标染色,观察SOD1-G93A转基因小鼠在症状前期、症状中期、终末期及对照组小鼠运动功能、皮质与腰髓P2Y12受体及小胶质细胞特异性标记物IBA1表达的变化情况。结果 SOD1-G93A转基因小鼠随病程进展运动功能逐渐下降;腰髓P2Y12受体随病程进展有逐渐降低趋势,与对照组比较,终末期P2Y12受体表达明显减低(P<0.05),皮质各期变化不明显;腰髓IBA1受体随病程进展有逐渐升高趋势,与对照组比较,终末期IBA1表达明显升高(P<0.05),皮质各期变化不明显。结论 随SOD1-G93A转基因小鼠病程进展运动功能逐渐降低,腰髓P2Y12受体表达减少,小胶质细胞增生明显,P2Y12受体介导的小胶质细胞活化可能参与了ALS的发生发展。     

家族性肌萎缩侧索硬化模型SOD1~(G93A)转基因鼠学习、记忆功能研究

目的了解SOD1G93A转基因鼠的学习、记忆功能。方法采用跳台试验及免疫组化方法,对30只SOD1G93A转基因鼠及30只同窝阴性对照小鼠进行研究比较。结果 60天、90天及120天SOD1G93A转基因鼠的记忆潜伏时间分别为68.00±47.16s、55.20±92.99s和110.10±116.52s,对照组分别为65.60±89.94s、158.00±88.31s和169.80±122.96s,5min内记忆错误次数分别为3.40±2.84次、5.20±3.08次和1.80±1.32次,对照组分别为3.30±2.16次、2.30±1.95次和2.00±2.75次,两者均有显著性差异。免疫组化可见SOD1G93A转基因鼠海马CA1、CA3及齿状回区泛素化蛋白的胞质内异常聚集,且阳性神经元比率较对照组有显著性差异(P<0.05)。结论 SOD1G93A转基因鼠存在空间辨别记忆功能受损,且可能与海马区泛素化蛋白异常聚集有关。     

scAAV9-IGF-1转导至G93A-SOD1小鼠神经元及其作用机制

目的 探索自我互补腺相关病毒载体介导的人胰岛素样生长因子-1 (scAAV9-IGF-1)转导至G93A-SOD1转基因小鼠神经元及其对线粒体的作用。方法 采用肌萎缩侧索硬化(ALS)的转基因G93A-SOD1及野生型(wild type-SOD1,WT-SOD1)小鼠为动物模型,在60 d龄时,同窝阳性G93A-SOD1转基因雌性小鼠采用随机的方法分配到治疗组肌肉注射scAAV9-IGF-1,载体对照组肌肉注射AAV9-GFP,及同年龄WT-SOD1作为阴性对照。在肌肉注射后约40～50 d时,通过免疫组化染色观察IGF-1在腰髓神经元中的表达,利用免疫荧光染色观测腰髓组织绿色荧光蛋白(GFP)的表达特点;用透射电镜观察腰髓前角运动神经元中线粒体的形态学变化;提取小鼠脊髓细胞进行流式细胞学分析线粒体膜电位变化;腓肠肌进行免疫组化染色观察线粒体变化。结果 免疫荧光染色观测腰髓组织GFP的表达主要在神经元,免疫组化染色观察IGF-1表达于腰髓神经元中。透射电镜观察GFP组线粒体存在嵴消失、空泡化、胞浆水肿、核染色质疏松,而IGF-1组线粒体形态与WT组相似,为长椭圆形,未见嵴消失、空泡化...     

内质网应激因子ATF6在hSOD1~(G93A)转基因小鼠脊髓中的表达

目的应用目前国际公认的肌萎缩侧索硬化(ALS)发病机制及临床前药物研究的动物模型hSOD1~(G93A)转基因小鼠,初步研究hSOD1~(G93A)小鼠脊髓中是否存在内质网应激中活性转录激活因子(ATF6)信号通路的激活,进而探究内质网应激在ALS发病机制中的作用。方法①hSOD1~(G93A)转基因小鼠及其同窝对照组小鼠的获得;②应用免疫组织化学方法观察转基因小鼠组和对照组显示脊髓前角运动神经元ATF6阳性细胞数量。结果症状早期和终末期转基因小鼠(分别为105~115d和120~130d),较对照组和无症状组转基因小鼠(60d)ATF6进入细胞核的运动神经元数量明显增多,差异有统计学意义(P0.05);症状早期和终末期相比较差异无统计学意义(P0.05);症状早期和终末期的一些细胞形态发生改变,出现皱缩,终末期运动神经元的数目减少。结论在无症状组时没有发现内质网应激因子ATF6的改变,但在疾病症状早期出现明显ATF6的改变,并随着疾病的进展而加重,说明内质网应激参与了ALS的发病,同时终末期脊髓前角运动神经元数量大幅减少。     

scAAV9-IGF-1对SOD1-G93A小鼠抗凋亡通路的作用

目的 探索以自我互补双链腺相关病毒9为载体介导的人胰岛素样生长因子-1 (scAAV9-IGF-1)对SOD1-G93A转基因小鼠抗凋亡通路的作用。方法 采用肌萎缩侧索硬化(ALS)的动物模型即转基因SOD1-G93A突变型及野生型(wild type-SOD1,WT-SOD1)小鼠,在其出生后60 d龄时,雌性同窝阳性SOD1-G93A转基因小鼠采用随机的方法分配到治疗组及溶剂对照组,治疗组全身多点肌肉注射scAAV9-IGF-1,溶剂对照组多点肌肉注射AAV9-GFP,同年龄WT-SOD1作为阴性对照组。在肌肉注射40～50 d后,利用PCR技术检测腰髓中IGF-1含量的变化,同时检测抗凋亡通路因子Bcl-xl、Bcl-2的mRNA含量变化,通过免疫组化染色观察抗凋亡通路因子Bcl-xl、Bcl-2在小鼠腰髓前角神经元中的表达。结果 PCR技术检测显示scAAV9-IGF-1处理后,腰髓中IGF-1的mRNA含量显著高于GFP对照组,抗凋亡通路因子Bclxl、Bcl-2的mRNA含量均高于溶剂对照组(^均P<0.05),而与WT组差异无统计学意义。免疫组化...     

SOD1基因突变子对AD转基因小鼠β-淀粉样蛋白表达影响的实验研究

目的探讨Cu/Zn SOD1基因表达对Aβ产生的影响.方法建立APP-C100和G93A SOD1基因共表达的转双基因小鼠,应用免疫细胞化学方法测定不同鼠龄转基因鼠海马神经元Aβ表达,Westem blot定量测定转基因鼠脑SCD1、APP、APP-C100和Aβ表达水平.结果低龄转双基因鼠与转单基因鼠之间Aβ水平无差异,与年龄匹配的转单基因鼠比较,高龄转双基因鼠脑Aβ水平升高,经统计处理差异无显著性意义(P＞O.05).但高龄转双基因鼠Aβ水平比低龄转双基因鼠明显升高(P＜0.05).结论转双基因鼠脑APP-C100和G93A SOD1基因共表达虽然未导致老年斑形成,但引起Aβ含量增加,推测其机制可能与SOD1基因突变子引起的氧化应激反应有关.     

Protein‐bound crotonaldehyde accumulates in the spinal cord of superoxide dismutase‐1 mutation‐associated familial amyotrophic lateral sclerosis and its transgenic mouse model

Growing evidence documents oxidative stress involvement in ALS. We previously demonstrated accumulation of a protein‐bound form of the highly toxic lipid peroxidation product crotonaldehyde (CRA) in the spinal cord of sporadic ALS patients. In the present study, to the determine the role for CRA in the disease processes of superoxide dismutase‐1 (SOD1) mutation‐associated familial ALS (FALS), we performed immunohistochemical and semiquantitative cell count analyses of protein‐bound CRA (P‐CRA) in the spinal cord of SOD1‐mutated FALS and its transgenic mouse model. Immunohistochemical analysis revealed increased P‐CRA immunoreactivity in the spinal cord of the FALS patients and the transgenic mice compared to their respective controls. In the FALS patients, P‐CRA immunoreactivity was localized in almost all of the chromatolytic motor neurons, neurofilamentous conglomerates, spheroids, cordlike swollen axons, reactive astrocytes and microglia, and the surrounding neuropil in the affected areas represented by the anterior horns. In the transgenic mice, P‐CRA immunoreactivity was localized in only a few ventral horn glia in the presymptomatic stage, in almost all of the vacuolated motor neurons and cordlike swollen axons and some of the ventral horn reactive astrocytes and microglia in the onset stage, and in many of the ventral horn reactive astrocytes and microglia in the advanced stage. Cell count analysis on mouse spinal cord sections disclosed a statistically significant increase in the density of P‐CRA‐immunoreactive glia in the ventral horns of the young to old G93A mice compared to the age‐matched control mice. The present results indicate that enhanced CRA formation occurs in motor neurons and reactive glia in the spinal cord of SOD1‐mutated FALS and its transgenic mouse model as well as sporadic ALS, suggesting implications for CRA in the pathomechanism common to these forms of ALS.     

The intermediolateral nucleus in sporadic amyotrophic lateral sclerosis

Summary Histological and morphometrical observations of the intermediolateral nucleus (IML) at the levels of the upper and lower thoracic segments (T2 and T9) were carried out in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 15 age-matched control subjects. Of the 18 ALS patients 6 had been on a respirator before death. No Bunina bodies were found in the IML neurons in either the ALS patients or the control subjects. Only a small number of spheroids were encountered rarely in the IML in both the patients and controls. The number of neurons in the IML in the non-respirator-supported ALS patients were reduced at T2, but well preserved at T9 compared with the control subjects. In the respirator-supported ALS patients, there was a marked reduction of IML neurons at both T2 and T9. Considering the absence of direct synaptic contacts with anterior horn cells, these neurons, without the formation of Bunina bodies, appeared to be involved primarily in the disease process in sporadic ALS.Supported in part by a research grant for CNS degenerative diseases from the Ministry of Health and Welfare, Japan     

Shy-Drager syndrome and amyotrophic lateral sclerosis. Cytoarchitectonic and morphometric studies of sacral autonomic neurons

In order to elucidate the morphological correlates of bladder-rectal dysfunctions in Shy-Drager syndrome, the sacral spinal cord was cytoarchitectonically studied and 3 groups of sacral motor neurons, the posterolateral motor neuron column (PL), inferior intermediolateral nucleus (IML) and cell group X of Onuf (Onuf), were morphometrically quantitated at the S3 level (5 cases), after which the results were compared with those from amyotrophic lateral sclerosis (5 cases) and an age-matched control group (4 cases). The sacral autonomic preganglionic nucleus of IML was localized chiefly in the S3-4 segments and was maximally developed in the caudal one-third of S3. The cell group X of Onuf was localized between the middle of S2 and the rostral one-third of S3 as a longitudinal slender column in the ventral horn. Between these two nuclei at the rostral S3 level, a connecting cellular bridge of neurons of intermediolateral cell type was identified. Morphometry disclosed a marked deprivation of IML, Onuf and somatic motor neurons in Shy-Drager syndrome and a severe loss of somatic motor neurons and a modest deprivation of IML neurons in ALS. These results imply that these two disorders distinguished by different clinical manifestations share a common loss of somatic motor and parasympathetic motor neurons at least in the sacral cord. There are, however, certain gradients in the severity of involvement in these heterogeneous cell groups.     

Pre- and postnatal development of noradrenergic projections to the rat spinal cord: an immunocytochemical study.

Using immunocytochemistry with a specific antiserum against noradrenaline, the pre- and postnatal development of noradrenergic (NA) projections to the rat spinal cord was studied from embryonic day 16 (E16) to adulthood (the day following nocturnal mating being considered as E0). In this study, pregnant animals were pre-treated with the MAO inhibitor pargyline (200 mg/kg i.p.), whereas postnatal animals received 100 mg/kg. In vibratome sections, noradrenaline-immunoreactive (NA-IR) axons were seen to invade the spinal cord at E16, at cervical and upper thoracic levels, from the ventral funiculus. At E18, small caliber NA-IR fibers were present in the ventral horn at all cord levels, and some fibers were seen in the intermediolateral cell column (IML) at thoracic level. The growth of axons towards the dorsal horn became noticeable by postnatal day 0 (P0). At P3, fine beaded and radially orientated NA-IR fibers were observed at all levels. The pattern of NA innervation of the dorsal horn was similar to that of the adult by P7. The segregation of noradrenaline immunoreactivity in the ventral and dorsal horns, the IML and the periependymal area was more obvious at all levels by P14 and P20. From P30 the NA innervation was similar to that found in the adult spinal cord. Thus, noradrenaline, like serotonin, was present early in the spinal cord before the onset of specific functions. In addition to and prior to its transmitter function, it might play a trophic role in the neurogenesis of the spinal cord.     

Thyrotropin-releasing hormone-immunoreactive neurons project from the ventral medulla to the intermediolateral cell column: partial coexistence with serotonin

Projections from medullary thyrotropin-releasing hormone (TRH) containing neurons to the intermediolateral cell column (IML) of the thoracic spinal cord were studied in the rat. Lesions of the ventral medullary reticular formation nuclei, nucleus paragigantocellularis lateralis and nucleus interfascicularis hypoglossi, decreased the thyrotropin-releasing hormone immunoreactivity in the IML. The ventral horn and dorsal horn contents of TRH were also reduced in rats with nucleus paragigantocellularis lateralis lesions. Coexistence of spinal cord TRH and serotonin was evaluated and quantified in 5,7-dihydroxytryptamine-treated rats. Treatment with the serotonin neurotoxin reduced the TRH content of the IML by 45% and of the ventral horn by 92%. These data show that TRH containing neurons project from the ventral medulla to IML and that approximately one-half of these TRH neurons are also serotonergic. Comparisons of the effects of the same lesions on the substance P and TRH content of the IML show that neither the origin of the SP and TRH neuronal projections to the IML, nor their coexistence with serotonin, are identical.     

Ontogeny of adrenergic fibers in rat spinal cord in relationship to adrenal preganglionic neurons

Adrenergic neurons in the C1 cell group in the rostral ventrolateral medulla oblongata contain epinephrine, as well as its biosynthetic enzyme, phenylethanolamine N-methyltransferase (PNMT). These neurons send axons to regions of the central nervous system known to regulate autonomic function, including the sympathetic preganglionic nuclei of thoracic and upper lumbar spinal cord. Previous studies have shown that PNMT is expressed in neurons located in the medulla oblongata on embryonic day 14; however, the development of the projections from these cells has not been studied. With the aid of high-performance liquid chromatography (HPLC) to determine levels of catecholamines and immunocytochemistry to demonstrate PNMT, the ontogeny of the adrenergic bulbospinal pathway in the embryonic, postnatal, and adult rat has been studied. In addition, the relationship between PNMT-immunoreactive (IR) fibers and retrogradely labeled sympathetic preganglionic neurons projecting to adrenal medulla are described. PNMT-IR fibers were first observed in the caudal medulla oblongata and lateral funiculus of spinal cord on gestational day 15(E15). On E16, PNMT-IR fibers in the thoracic spinal cord were observed in the intermediate gray matter at the level of the lateral horn. Epinephrine was measureable in spinal cord on E20. Both the density of PNMT-IR fibers and the levels of epinephrine increased to a maximum during the second postnatal week and then declined to adult levels. These observations suggest that a period of adrenergic hyperinnervation of spinal sympathetic nuclei occurs during the neonatal period. PNMT-IR terminals in spinal cord were observed, primarily, although not exclusively, in sympathetic nuclei of thoracic cord and parasympathetic nuclei of upper sacral cord. Adrenergic fibers in the intermediolateral nucleus (IML) and the central autonomic nucleus (CAN) dorsal to the central canal were particularly dense during the second postnatal week in both midthoracic and upper sacral segments. In the neonate, a "ladder-like" pattern of PNMT-IR fiber staining was observed which represented transverse fiber bundles connecting IML with CAN and extensive longitundinal fiber bundles along the border of the funiculus in IML. At all spinal levels, adrenergic fibers were also observed adjacent to the ependyma dorsal or lateral to the central canal. The relationship between adrenal preganglionic neurons and PNMT-IR fibers in IML was examined on postnatal days 4, 15, and 60. With retrograde labeling from adrenal medulla, it was demonstrated that PNMT-IR fibers are associated with adrenal preganglionic neurons throughout postnatal development.(ABSTRACT TRUNCATED AT 400 WORDS)     

Acute glial activation by stab injuries does not lead to overt damage or motor neuron degeneration in the G93A mutant SOD1 rat model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease where motor neurons within the brain and spinal cord are lost, leading to paralysis and death. Recently, a correlation between head trauma and the incidence of ALS has been reported. Furthermore, new invasive neurosurgical studies are being planned which involve inserting needles directly to the spinal cord. We therefore tested whether acute trauma to the spinal cord via a knife wound injury would lead to accelerated disease progression in rodent models of ALS (SOD1^G93A rats). A longitudinal stab injury using a small knife was performed within the lumbar spinal cord region of presymptomatic SOD1^G93A rats. Host glial activation was detected in the lumbar area surrounding a micro-knife lesion at 2 weeks after surgery in both wild type and SOD1^G93A animals. However, there was no sign of motor neuron loss in the injured spinal cord of any animal and normal motor function was maintained in the ipsilateral limb. These results indicate that motor neurons in presymptomatic G93A animals are not affected by an invasive puncture wound injury involving reactive astrocytes. Furthermore, acute trauma alone does not accelerate disease onset or progression in this ALS model which is important for future strategies of gene and cell therapies directly targeting the spinal cord of ALS patients.     

Non-motor Neuron System in Amyotrophic Lateral Sclerosis: Involvement of Clarke's Column and Intermediolateral Nucleus

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects the motor neuron system. However dose only the motor neuron system degenerate selectively in this disease? On the basis of histologic and morphometric studies on Clarke's column and intermediolateral nucleus (IML) neurons, which belong to the non-motor neuron system in the spinal cord, we report in this Symposium presentation that in sporadic ALS, they are also primarily involved in the disease process. However, the rate of degeneration of these neurons is much slower than that of lower motor neurons. Our results indicate that Clarke's column neurons and IML neurons in the lower thoracic segments may start to disappear after the patients have begun to require respiratory support, which is the final stage of the natural hintory of the disease. In addition, it should also be empasized that Bunina bodies and spheroids are neuropathological features of Clarke's column in ALS patients, but not of the IML.     

Sympathetic disturbances increase risk of sudden cardiac arrest in sporadic ALS

BACKGROUND: ALS exclusively involves motor neurons, however, accumulating evidence suggests involvement of sympathetic neurons, as in other diseases including Parkinson's disease and multiple system atrophy. In these diseases increased risk of sudden cardiac arrest is established, while that in ALS remains uncertain. METHODS: The authors retrospectively studied 12 pathologically confirmed sporadic ALS patients who received no assisted ventilation. Among them, two patients died of sudden cardiac arrest. Changes in QTc interval and dispersion, indices of sympathetic activities obtainable by routine electrocardiograms, were evaluated at the early stage and the terminal stage. Pathologically, intermediolateral nucleus (IML) sympathetic neurons in the upper thoracic cord were examined. RESULTS: The QTc intervals and dispersion were significantly increased at the terminal stage compared with that at the early stage (p<0.01). The numbers of IML neurons were significantly lower in ALS patients than in controls (p=0.017), and had linear inverse correlation with the rate of increases in maximum QTc interval and QTc dispersion (p=0.01, r=-0.915 and p=0.02, r=-0.884). Notably, two patients with sudden cardiac arrest showed longer QTc interval, larger QTc dispersion, and lower number of IML neurons than most of others. CONCLUSIONS: Patients with ALS had reduced sympathetic activities at the terminal stage of disease, presumably due to neuronal loss in IML, which may increase risk of sudden cardiac arrest. Thus, prolonged QTc intervals and increased QTc dispersion may suggest an increased risk of sudden death in ALS, as in other neurodegenerative diseases.     

Is motoneuronal cell death in amyotrophic lateral sclerosis apoptosis?

To clarify the controversy concerning whether the cell death of motor neurons in ALS is apoptosis, we investigated the expression of Apaf‐1 and caspase‐9 mRNA in spinal cord tissue obained at autopsy from patients with ALS and controls using RT‐PCR; the presence of in situ nuclear DNA fragmentation in motor neurons by the TdT‐mediated dUTP‐biotin nick end‐labeling (TUNEL) method; and immunocytochemical localization of Apaf‐1 and caspase‐3, which are known as promotors of apoptotic processes. Although Apaf‐1 and caspase‐9 mRNAs levels were increased in ALS, Apaf‐1 immunoreactivity (IR) showed no significant difference between ALS and the control, and caspase‐3 IR was not observed in ALS motoneurons, casting doubt on the notion that motor neurons in ALS undergo death by the classic apoptotic pathway. Although TUNEL‐positive motor neurons were frequently observed in the anterior horn in ALS, these neurons always showed an atrophic cell body with a shrunken and pyknotic nucleus, indicating that they were at the terminal stage of degeneration. No apoptotic bodies were seen. These findings suggest that the mechanism of motor neuronal cell death in ALS might not be apoptosis, but some other as yet unidentified mechanism.