6-羟基多巴毁损间脑A11区域对缺铁饮食小鼠运动功能的影响

目的观察6-羟基多巴(6-hydroxydopamine,6-OHDA)定向毁损间脑A11核团对缺铁饮食小鼠运动功能的影响,探讨此方法建立不安腿综合征(Restless legs syndrome,RLS)模型的可行性。方法取60只4周龄C57BL/6雄性小鼠,30只予缺铁饮食(iron deficiency diet,ID),另外30只予正常饮食(normal diet,ND)。1个月后观察小鼠的运动活性,包括水平方向的运动次数(HACTV)、垂直方向的运动次数(VACTV)、总的运动距离(TOT-DIST)和运动时间(MOVTIME)。随后每组各取15只小鼠定向注射6-OHDA至双侧A11区域,其余小鼠注射PBS。并继续原来的饮食处理。毁损1个月后所有动物皮下注射多巴胺受体激动剂ropinirole,比较给药前后小鼠运动活性的变化。对A11区域进行酪氨酸羟化酶(tyrosine,TH)染色计数多巴胺(DA)神经元。结果饮食治疗1个月后,缺铁饮食组小鼠的三项运动活性均显著高于正常饮食组(均为P<0.01)。6-OHDA毁损A11核团可显著增加小鼠的各项运动活性(均为P<0.01)。D2受体激动剂ropinirole可以使小鼠增高的运动活性下降到基线水平。6-OHDA毁损可致A11区域DA能神经元明显减少。结论对C57BL/6雄性小鼠在缺铁饮食基础上进行A11区域的6-OHDA毁损建立的模型,能较好的模拟RLS的临床征象,可用作RLS的动物模型。     

Effects of Transcutaneous Spinal Direct Current Stimulation in Idiopathic Restless Legs Patients

BackgroundTranscutaneous spinal direct current stimulation (tsDCS) is a new non-invasive technique to modulate spinal cord activity. The pathophysiological concept of primary RLS proposes increased spinal excitability.ObjectiveThis pilot study used tsDCS to reduce pathologically enhanced spinal excitability in RLS patients and to thereby ameliorate clinical symptoms.Methods20 patients with idiopathic RLS and 14 healthy subjects participated in this double-blinded, placebo-controlled study. All participants received one session of cathodal, anodal and sham stimulation of the thoracic spinal cord for 15 min (2.5 mA) each, in randomized order during their symptomatic phase in the evening. The soleus Hoffmann-reflex with Hmax/Mmax-ratio and seven different H2/H1-ratios (of two H-reflex responses to double stimuli) were measured. The RLS symptoms were assessed by a visual analogue scale (VAS). All parameters were measured before and twice after tsDCS.ResultsRLS patients showed increased H2/H1-ratios during their symptomatic phase in the evening. Application of anodal stimulation led to a decreased H2/H1-ratio for 0.2 and 0.3 s interstimulus intervals in patients. Furthermore, application of anodal and cathodal stimulation led to a reduction in restless legs symptoms on the VAS, whereas application of sham stimulation had no effects on either the VAS or on the H2/H1-ratio in patients. VAS changes did not correlate with changes of H2/H1-ratios.ConclusionsThis is the first tsDCS study in idiopathic RLS, which resulted in short-lasting clinical improvement. Furthermore, our results support the pathophysiological concept of spinal cord hyperexcitability in primary RLS and provide the basis for a new non-pharmacological treatment tool.     

Altered cortical gray matter volume and functional connectivity after transcutaneous spinal cord direct current stimulation in idiopathic restless legs syndrome

ObjectiveTo explore the neurophysiological mechanism of clinically effective transcutaneous spinal cord direct current stimulation (tsDCS) on idiopathic restless legs syndrome (RLS), structural magnetic resonance imaging (sMRI), and resting-state functional MRI (rs-fMRI) were applied to reveal the structural and functional changes in idiopathic RLS patients after tsDCS.MethodsThirty idiopathic RLS patients and 20 gender- and age-matched healthy controls (HC) were enrolled. All patients were randomly divided into anodal treatment group and sham treatment group and were treated with tsDCS for 2 weeks. The international RLS Rating Scale (IRLS-RS) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the severity of RLS and sleep quality respectively. The sMRI and rs-fMRI data of anodal treatment group and HC were collected. Voxel-based morphology (VBM) and resting-state functional connectivity analysis were used to assess the change of cortical gray matter volume (GMV) and corresponding functional connectivity (FC) respectively in anodal treatment group after tsDCS treatment.ResultsSham treatment group showed no significant change in IRLS-RS and PSQI scores after tsDCS, while significant decrease scores were observed in anodal treatment group, and the improvement sustained up to 2 weeks. Anodal treatment group showed significant regional decrease of GMV in bilateral cuneus compared to the HC. After tsDCS treatment, the GMV in the bilateral cuneus and left ventral post central gyrus (PoCG_L) decreased significantly. The FC between bilateral cuneus and left primary visual cortex (V1_L), and between right cuneus (Cune_R) and right lingual gyrus (LG_R) increased significantly after tsDCS, whereas the FC between PoCG_L and supplementary motor area (SMA) decreased significantly. The changed FC between PoCG_L and SMA, between Cune_R and V1_L were correlated with the changed IRLS-RS.ConclusionDisturbance of sensorimotor network and visual processing network may be involved in the pathogenesis of RLS. tsDCS probably can regulate FC in the sensorimotor cortex and visual processing cortex to relieve the symptom of RLS. Continuous tsDCS may improve the symptoms of RLS patients for a long time. tsDCS probably could provide a potential non-pharmacologic treatment for idiopathic RLS patients.     

Motor activity affects dopaminergic and noradrenergic systems of the dorsal horn of the rat lumbar spinal cord

Dopamine (DA) and noradrenaline (NA) modulate responses to nociceptive stimuli, within the dorsal horn of the spinal cord. Both neurotransmitters may play a role in supraspinal regulation in response to proprioceptive afferences to the dorsal horn. However, direct evidence of changes in neurotransmitter release within the dorsal horn due to non-noxious stimuli is lacking. The present study was designed to determine, whether non-nociceptive exercise produces changes in release of DA and NA within the dorsal horn, and whether these changes are associated with long-lasting inhibition after the exercise stops. Microdialysis probes, implanted in layers 2-5 of Rexed, in combination with high-performance liquid chromatography coupled to electrochemical detection (HPLC-EC) were used to measure concentrations of DA and NA metabolite (MHPG) in lumbar spinal cords of rats. Microdialysate was sampled before, during, and after a treadmill exercise of one hour. Results indicate that DA and NA releases are inhibited during non-nociceptive motor activity. At rest, DA concentration was 204 ± 10.5 pg/10 μl and was significantly decreased during exercise to -11.4% (P ≤ 0.05). Greater decrease occurred after 30 min of exercise and was of -31.4% (P ≤ 0.05). Similarly, MHPG was significantly decreased of -18% during exercise (P ≤ 0.05). When exercise stopped, both systems showed long-lasting inhibition. Exercise post-release lasted 30 min for DA and 90 min for MHPG. MHPG greatest decrease of -47.8% occurred 30 min after stopping the exercise (P ≤ 0.001). Thus, DA and NA systems seem to respond to exercise-induced proprioceptive afferent stimuli to the dorsal horn.     

Monocyte recruitment and myelin removal are delayed following spinal cord injury in mice with CCR2 chemokine receptor deletion

The inflammatory response initiated after spinal cord injury (SCI) is characterized by the accumulation of macrophages at the impact site. Monocyte chemoattractant protein-1 (MCP-1) is a strong candidate for mediating chemotaxis of monocytes to the injured nervous system. To help in defining the role of MCP-1 in inflammation after SCI, we evaluated the time course of macrophage accumulation for 2 weeks following a midthoracic spinal cord contusion injury in mice lacking CCR2, a principal receptor for MCP-1. Mice with a deletion of CCR2 resulted in significantly reduced Mac-1 immunoreactivity restricted to the lesion epicenter at 7 days postinjury. The regions devoid of Mac-1 immunoreactivity corresponded to areas of reduced myelin degradation at this time. By 14 days postinjury, however, there were no differences in Mac-1 staining between CCR2 (+/+) and CCR2 (-/-) mice. Analyses of mRNA levels by RNase protection assay (RPA) revealed increases in MCP-1 as well as MCP-3 and MIP-2 mRNA at 1 day postinjury compared with 7 day postinjury. There were no differences in chemokine expression between CCR2-deficient mice and wild-type littermate controls. The CCR2-deficient mice also exhibited reduced expression of mRNA for chemokine receptors CCR1 and CCR5. Together, these results indicate that chemokines acting through CCR2 contribute to the early recruitment of monocytes to the lesion epicenter following SCI.     

Changes in truncated trkB and p75 receptor expression in the rat spinal cord following spinal cord hemisection and spinal cord hemisection plus neurotrophin treatment

Although numerous studies have examined the effects of neurotrophin treatment following spinal cord injury, few have examined the changes that occur in the neurotrophin receptors following either such damage or neurotrophin treatment. To determine what changes occur in neurotrophin receptor expression following spinal cord damage, adult rats received a midthoracic spinal cord hemisection alone or in combination with intrathecal application of brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3). Using immunohistochemical and in situ hybridization techniques, p75, trkA, trkB, and trkC receptor expression was examined throughout the spinal cord. Results showed that trkA, full-length trkB, and trkC receptors were not present in the lesion site but had a normal expression pattern in uninjured parts of the spinal cord. In contrast, p75 receptor expression occurred on Schwann cells throughout the lesion site. BDNF and NT-3 (but not saline) applied to the lesion site increased this expression. In addition, the truncated trkB receptor was expressed in the border between the lesion and intact spinal cord. Truncated trkB receptor expression was also increased throughout the white matter ipsilateral to the lesion and BDNF (but not NT-3 or saline) prevented this increase. The study is the first to show changes in truncated trkB receptor expression that extend beyond the site of a spinal cord lesion and is one of the first to show that BDNF and NT-3 affect Schwann cells and/or p75 expression following spinal cord damage. These results indicate that changes in neurotrophin receptor expression following spinal cord injury could influence the availability of neurotrophins at the lesion site. In addition, neurotrophins may affect their own availability to damaged neurons by altering the expression of the p75 and truncated trkB receptor.     

消幻汤对精神分裂症大鼠模型自主活动及纹状体内多巴胺含量的影响

目的 通过研究消幻汤对精神分裂症动物模型自主活动及纹状体内多巴胺及其代谢产物含量的影响,探讨消幻汤治疗精神分裂症的可能机制.方法 雌性Sprague Dawley大鼠,分为:正常组、模型组、消幻汤组、利培酮组,每组13只.腹腔0.1 mg/kg的MK801连续注射14d制作模型后,分别给予相应治疗.应用刻板行为评分、旷场实验及库仑阵列电化学高效液相色谱法测定相应指标.结果 (1)与正常组比较,消幻汤可以有效抑制精神分裂症大鼠模型刻板行为(P＜0.05),与利培酮组效果相当;(2)给药后消幻汤组(243.75±86.82)格及利培酮组(242.10±89.56)格,自主活动与模型组(315.08±65.93)格相比,差异有统计学意义(P＜0.05);(3)神经递质化验结果显示:消幻汤组与利培酮组,多巴胺及二羟基苯乙酸水平与模型组比较含量明显减低(P＜0.05);消幻汤组高香草酸含量与比模型组显著降低(P＜0.05),而利培酮组与模型组比较差异无统计学意义(P＞0.05).结论 消幻汤可以增加精神分裂症模型大鼠的自主活动并改善认知损害,疗效与利培酮相当;消幻汤可以调节纹状体内多巴胺及其代谢产物含量,从而达到治疗精神分裂症的作用.     

脊髓电刺激治疗复杂区域性疼痛综合征

目的探讨脊髓电刺激术（spinal cord stimulation,SCS）治疗复杂性区域性疼痛综合征（complex regional pain syndrome,CRPS）的有效性。方法回顾性分析4例CRPS病例,其均经脊髓电刺激手术治疗并随访1年以上,采用视觉模拟疼痛评分（VAS）评估疼痛转归。结果病人术后VAS评分平均降低5．4,3例病人疼痛缓解大于50％,无手术并发症。结论SCS能够安全、有效地治疗CRPS。、     

Neonatal androgen‐dependent sex differences in lumbar spinal cord dopamine concentrations and the number of A11 diencephalospinal dopamine neurons

A₁₁ diencephalospinal dopamine (DA) neurons provide the major source of DA innervation to the spinal cord. DA in the dorsal and ventral horns modulates sensory, motor, nociceptive, and sexual functions. Previous studies from our laboratory revealed a sex difference in the density of DA innervation in the lumbar spinal cord. The purpose of this study was to determine whether sex differences in spinal cord DA are androgen dependent, influenced by adult or perinatal androgens, and whether a sex difference in the number of lumbar‐projecting A₁₁ neurons exists. Adult male mice have significantly higher DA concentrations in the lumbar spinal cord than either females or males carrying the testicular feminization mutation (tfm) in the androgen receptor (AR) gene, suggesting an AR‐dependent origin. Spinal cord DA concentrations are not changed following orchidectomy in adult male mice or testosterone administration to ovariectomized adult female mice. Administration of exogenous testosterone to postnatal day 2 female mice results in DA concentrations in the adult lumbar spinal cord comparable to those of males. Male mice display significantly more lumbar‐projecting A₁₁ DA neurons than females, particularly in the caudal portion of the A₁₁ cell body region, as determined by retrograde tract tracing and immunohistochemistry directed toward tyrosine hydroxylase. These results reveal an AR‐dependent sex difference in both the number of lumbar‐projecting A₁₁ DA neurons and the lumbar spinal cord DA concentrations, organized by the presence of androgens early in life. The AR‐dependent sex difference suggests thyat this system serves a sexually dimorphic function in the lumbar spinal cord. J. Comp. Neurol. 518:2423–2436, 2010. © 2010 Wiley‐Liss, Inc.     

Changes in expression of NMDA receptor subunits in the rat lumbar spinal cord following neonatal nerve injury

The vulnerability of motoneurones to glutamate has been implicated in neurological disorders such as amyotrophic lateral sclerosis but it is not known whether specific receptor subtypes mediate this effect. In order to investigate this further, the expression of N-methyl-D-aspartate (NMDA) receptor subunits was studied during the first three post-natal weeks when motoneurones are differentially vulnerable to injury following neonatal nerve crush compared to the adult. Unilateral nerve crush was carried out at day 2 after birth (P2) which causes a decrease of 66% in motoneurone number by 14 days (P14). To study receptor expression in identified motoneurones, serial section analysis was carried out on retrogradely labelled common peroneal (CP) motoneurones by combined immunocytochemistry and in situ hybridization (ISH). mRNA levels were also quantified in homogenates from lumbar spinal cords in which the side ipsilateral to the crush was separated from the contralateral side. The NR1 subunit of the NMDA receptor was widely distributed in the spinal cord being expressed most strongly in motoneurone somata particularly during the neonatal period (P3-P7). The NR2 subunits were also expressed at higher levels in the somata and dendrites of neonatal motoneurones compared to older animals. NR2B mRNA was expressed at low to moderate levels throughout the studied period whereas NR2A mRNA levels were low until P21. Following unilateral nerve crush, an initial decrease in NR1 mRNA occurred at one day after nerve crush (P3) in labelled CP motoneurones ipsilateral to the crush which was followed by a significant increase in NR1 subunit expression at 5 days post-injury. This increase was bilateral although reaching greater significance ipsilateral to the crush compared with sham-operated animals. A significant increase in NR1 and NR2B mRNA post injury was also detected in spinal cord homogenates. In addition, the changes in levels of NR1 and NR2B mRNA were reflected by comparable bilateral changes at P7 in receptor protein determined by quantitative immunocytochemical analysis of NR1 and NR2 subunit expression in identified CP motoneurones indicating a co-ordinated regulation of receptor subunits in response to injury.     

BMS-345541对脊髓损伤后大鼠NF-κB表达及运动功能的影响

This study sought to elucidate the changes of nuclear factor kappa B (NF-κB) expression and locomotor function of hind limb after subdural injection of BMS-345541 was applied in rats with acute spinal cord injury.The results indicated that BMS-345541 treatment reduced the expression of NF-kB at 24 hours after injury,compared with normal saline-tre ated rats.This treatment also led to a significant improvement in locomotor functional recovery at 14 days after injury.Overall,the findings demonstrated that BMS-345541 significantly ameliorated spinal cord injury-induced hind limb dysfunction by inhibiting the expression of NF-kB after spinal cord injury.     

Efficacy of oral iron in patients with restless legs syndrome and a low-normal ferritin: A randomized, double-blind, placebo-controlled study

Background and PurposeRestless Legs Syndrome (RLS) is a primary disorder of sensation that affects sleep and has been associated with iron deficiency. The purpose of this study was to determine if symptomatic RLS patients with low-normal serum ferritin levels benefit from oral iron replacement.Patients and MethodsThis was a randomized, placebo-controlled, double-blinded study. Eligible patients were randomized to oral iron therapy vs. appearance-matched placebo and followed over a 12 week period.ResultsBaseline International Restless Leg Scale (IRLS) scores for the treatment (24.8 ± 5.72) and placebo (23.0 ± 5.03) groups were similar. Baseline ferritin levels for the treatment (40.6 ± 15.3 ng/ml) and placebo (36.7 ± 20.8 ng/ml) groups were also similar. After 12 weeks, IRLS scores decreased more in the treatment arm (10.3 ± 7.40) than in the placebo arm (1.14 ± 5.64), (p = 0.01). Ferritin levels increased more in the treatment arm (25.1 ± 20.3 ng/ml) than in the placebo arm (7.5 ± 13.7 ng/ml), (p = 0.04). We observed a nonsignificant trend toward improved quality of life in the treated patients, (p = 0.07).ConclusionsThis is the first double-blinded, placebo-controlled study to demonstrate statistically significant improvement in RLS symptoms using oral iron therapy in patients with low-normal ferritin. The findings from this study suggest that additional larger randomized placebo-controlled trials of iron as treatment for patients with low-normal ferritin are warranted.     

伏隔核毁损对MAP模型大鼠行为及脑内DA受体影响的研究

目的探讨立体定向伏隔核毁损对甲基苯丙胺(MAP)模型大鼠行为学及不同脑区多巴胺D2受体表达的影响。方法80只SpraqueDawley(SD)大鼠随即分为对照组、模型组、假手术组和手术组,每组各20只;采用经腹腔注射MAP制备精神分裂症模型,立体定向-直流电毁损伏隔核,观察大鼠刻板行为变化,原位杂交法观察额叶、颞叶、边缘区及脑干部位D2受体表达。结果与对照组比较,模型组及假手术组大鼠刻板行为评分及各个脑区D2受体表达均显著增加;而与模型组及假手术组比较,手术组大鼠刻板行为评分及各脑区DA受体阳性细胞数目均显著减少。结论伏隔核毁损可能是通过抑制使用MAP而诱发的脑内D2表达的亢进而改变其行为学的异常。     

A circulating ghrelin mimetic attenuates light-induced phase delay of mice and light-induced Fos expression in the suprachiasmatic nucleus of rats

Anatomical evidence suggests that the ventromedial arcuate nucleus (vmARC) is a route for circulating hormonal communications to the suprachiasmatic nucleus (SCN). Whether this vmARC-SCN connection is involved in the modulation of circadian activity of the SCN is not yet known. We recently demonstrated, in rats, that intravenous (i.v.) injection of a ghrelin mimetic, GHRP-6, during the daytime activated neurons in the vmARC and reduced the normal endogenous daytime Fos expression in the SCN. In the present study we show that i.v. administration of GHRP-6 decreases light-induced Fos expression at ZT13 in the rat SCN by 50%, indicating that light-induced changes in the SCN Fos expression can also be reduced by GHRP-6. Because it is difficult to study light-induced phase changes in rats, we examined the functional effects of GHRP-6 on light-induced phase shifts in mice and demonstrated that peripherally injected GHRP-6 attenuates light-induced phase delays at ZT13 by 45%. However, light-induced Fos expression in the mice SCN was not blocked by GHRP-6. These results illustrate that acute stimulation of the ghrelinergic system may modulate SCN activity, but that its effect on light-induced phase shifts and Fos expression in the SCN might be species related.     

成年大鼠脊髓全横断损伤后酪氨酸激酶受体C在脊髓和大脑皮层的表达

目的 研究神经营养因子3(neurotrophin-3,NT-3)的受体-酪氨酸激酶受体C(tyrosine kinase receptor C,TrkC)在脊髓损伤(spinal cord injury,SCI)后神经重塑中的作用.方法 研究脊髓全横断损伤大鼠手术后第1、3、7和14 d时,低位胸髓节段和大脑中央前回...     

L-DOPA-induced dyskinesia in adult rats with a unilateral 6-OHDA lesion of dopamine neurons is paralleled by increased c-fos gene expression in the subthalamic nucleus

Levodopa (L-DOPA), the metabolic precursor of dopamine, is widely used as a pharmacological agent for the symptomatic treatment of Parkinson's disease. However, long-term L-DOPA use results in abnormal involuntary movements such as dyskinesias. There is evidence that abnormal cell signaling in the basal ganglia is involved in L-DOPA-induced dyskinesia. The subthalamic nucleus (STN) plays a key role in the circuitry of the basal ganglia and in the pathophysiology of Parkinson's disease. However, the contribution of the STN to L-DOPA-induced dyskinesias remains unclear. The objective of this work was to study the effects of acute or chronic systemic administration of L-DOPA to adult rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of dopamine neurons on c-fos expression in the STN and test the hypothesis that these effects correlate with L-DOPA-induced dyskinesias. c-fos mRNA expression was measured in the STN by in situ hybridization histochemistry at the single cell level. Our results confirm earlier evidence that the chronic administration of L-DOPA to rats with a unilateral 6-OHDA lesion increases c-fos expression in the STN. We also report that c-fos expression can be increased following an acute injection of L-DOPA to 6-OHDA-lesioned rats but not following a chronic injection of L-DOPA to sham-operated, unlesioned rats. Finally, we provide evidence that the occurrence and severity of dyskinesia is correlated with c-fos mRNA levels in the ipsilateral STN. These results suggest that altered cell signaling in the STN is involved in some of the behavioral effects induced by systemic L-DOPA administration.     

Spinal cord acetylcholine content: the consequence of transection or treatment with the neurotoxin 6-aminonicotinamide

The distribution of choline (Ch) and acetylcholine (ACh) within the rat spinal cord was found to be rather uniform with values for Ch of about 280 pmol/mg protein and for ACh of about 250 pmol/mg protein. Cord transection at the T10-11 level did not reduce ACh below the lesion but there was about a 30% decrease of ACh in the thoracic region suggesting the presence of cholinergic fibers that ascend and terminate within the cord. Treatment of rats with the neurotoxin 6-aminonicotinamide resulted in spastic hindlimb paralysis and a loss of ACh in the lumbar region of the cord.