Neural localization of addicsin in mouse brain

Addicsin is a member of the prenylated Rab acceptor (PRA) 1 domain family and a murine homolog of the rat glutamate-transporter-associated protein 3-18 (GTRAP3-18). This protein is considered to function as a modulator of the neural glutamate transporter excitatory amino acid carrier 1 (EAAC1). However, its molecular functions remain largely unknown. Here, we examined the regional and cellular localization of addicsin in the central nervous system (CNS) by using a newly generated antibody specific for the protein. Distribution analysis by Western blot and immunohistochemistry demonstrated that the protein was widely distributed in various regions of the mature CNS, including the olfactory bulbs, cerebral cortex, amygdala, hippocampus CA1–3 fields, dentate gyrus, and cerebellum. Double immunofluorescence analysis revealed that addicsin was expressed in the somata of principal neurons in the CNS such as the pyramidal cells and gamma-aminobutyric acid (GABA)-ergic interneurons scattered in the hippocampal formation. Furthermore, the protein showed pre-synaptic localization in the stratum lucidum of the CA3 field of the hippocampal formation. Subcellular localization analysis of highly purified synaptic fractions prepared from mouse forebrain supported the cytoplasmic and pre-synaptic distribution of addicsin. These results suggest that addicsin has neural expression and may play crucial roles in the basic physiological functions of the mature CNS.     

精氨酸血管加压素 mRNA在不同免疫应答期大鼠下丘脑室旁核的表达变化

目的研究大鼠下丘脑室旁核(PVN)内精氨酸血管加压素(AVP)mRNA的表达与免疫应答反应间的动态关系.方法建立免疫增强及免疫抑制大鼠模型,应用原位杂交组织化学及图像分析技术检测免疫反应不同时期大鼠PVN内AVP mRNA的动态变化.结果①免疫抑制组大鼠PVN单个细胞内AVP mRNA阳性杂交信号的平均面积明显低于免疫增强组及对照组(P＜0.05).②PVN单个细胞内AVP mRNA阳性杂交信号的平均灰度值在免疫反应高峰时显著低于免疫反应开始增强时(P＜0.05),在免疫抑制最低时却明显高于免疫反应开始受抑制时(P＜0.05).③AVP mRNA阳性杂交信号在PVN内所占的总面积在免疫反应高峰时显著大于免疫反应开始增强时和对照组(P＜0.05),在免疫抑制最低时则明显小于免疫反应开始受抑制时(P＜0.05).④AVP mRNA阳性杂交信号在整个PVN内的平均灰度值在免疫反应高峰时明显低于免疫反应开始增强时(P＜0.05),在免疫抑制最低时却明显高于免疫反应开始受抑制时(P＜0.05).结论 PVN内AVP mRNA的含量与免疫应答反应的强度成正比,AVP基因的转录随免疫应答反应的变化而变化.     

人工髓核置换治疗腰椎间盘突出症

介绍一种骨科新技术,人工髓核置换治疗腰椎间盘突出症。通过其适应证与禁忌证、型号大小和手术方法,结合作者手术经验和短期观察进行讨论,部分患者术后出现短暂的剧烈腰痛,口服药物后缓解。在人工椎间盘置换和椎间隙最终行融合之前,恢复脊柱节段的功能,是脊柱外科的发展趋势,人工髓核是一种选择。     

神经节苷脂对不完全性脑缺血后齿状回NOS阳性神经元表达的影响

目的 :探讨神经节苷脂 (GM1 )对不完全性脑缺血及再灌注不同时间后海马齿状回一氧化氮合酶(NOS)的影响。方法 :用双侧颈总动脉夹闭加放血的方法制成大鼠不完性脑缺血及再灌注模型 ,以还原尼克酰胺腺嘌呤二核苷酸脱氢酶 (NDAPH- d)组织化学方法观察缺血及再灌注后海马齿状回 NOS阳性神经细胞变化及 GM1 对其的影响。结果 :海马齿状回在缺血 30 min时 NOS阳性细胞数最高 (4 3.6 7± 6 .71) ,再灌注 2 h、12 h、2 4 h、3d后逐渐下降 ,5 d时恢复正常水平。而 GM1 能防止脑缺血及再灌注后神经细胞受损和 NOS阳性神经细胞变化。结论 :GM1 对大鼠不完全性脑缺血及再灌注不同时间后海马齿状回 NOS的表达有抑制作用     

Performing functional magnetic resonance imaging in patients with Parkinson's disease treated with deep brain stimulation.

Deep brain stimulation (DBS) is a relatively novel treatment in advanced Parkinson's disease (PD). Functional magnetic resonance imaging (fMRI) is a useful technique for examining the effects of DBS both within the basal ganglia and its cortical connectivity. There are technical difficulties in imaging patients with PD, and the DBS itself can generate image artifacts. We describe aspects related to optimizing the fMRI acquisition parameters in patients with DBS and the results of sensorimotor activation tasks performed by four PD patients during hand, foot, and tongue movements, both before and after DBS implant. Provided that all safety conditions are followed, it is possible to perform fMRI in patients with PD and DBS. The standard DBS surgical procedure has to be slightly modified in order to reduce image artifacts. The event-related design provided increased power to detect sensorimotor cortex and basal ganglia activation.     

Improvement in a quantitative measure of bradykinesia after microelectrode recording in patients with Parkinson's disease during deep brain stimulation surgery.

It is widely accepted that patients with Parkinson's disease experience immediate but temporary improvement in motor signs after surgical implantation of subthalamic nucleus (STN) deep brain stimulating electrodes before the electrodes are activated, although this has never been formally studied. Based on anecdotal observations that limb mobility improved just after microelectrode recording (MER) during deep brain stimulation (DBS) procedures, we designed a prospective study to measure upper extremity bradykinesia using a quantitative measure of angular velocity. Measurements were made pre- and post-MER and during intraoperative DBS. Analysis of 98 STN DBS procedures performed on 61 patients showed that MER did not create adverse clinical symptoms despite concerns that MER increases morbidity. Quantitative upper extremity bradykinesia improved after MER alone, and further improvement was seen during intraoperative DBS. Electrophysiological data from each case were then compared to the improvement in bradykinesia post-MER alone and a significant correlation was found between the improvement in arm bradykinesia, the number of passes through the STN with somatosensory driving, and also with the number of arm cells with somatosensory driving in the STN, but not with total number of passes, total number of passes through the STN, or total number of cells with somatosensory driving in the STN. This study demonstrates that there is a significant improvement in upper extremity bradykinesia just after MER, before inserting or activating the DBS electrode in patients with Parkinson's disease who undergo STN DBS.     

幼儿小脑齿状核的微血管构筑

目的:以幼儿为研究对象观察小脑齿状核微血管构筑的形态学特点。方法:采用改良碱性磷酸酶染色法显示小脑齿状核内的微血管形态及吻合,并测血管密度。结果:本实验首次成功地显示出小脑齿状核内微静脉,且观察到微动脉和微静脉间的吻合。小脑齿状核的微血管多为树根状,分支多以大锐角和弧形发出,且彼此吻合成网,其密度明显高于周围髓质区。结论:小脑齿状核内微血管近似直角和弧形的弯曲,可能是该区易发生出血的形态学基础。其密度较周围髓质高很多,与该部位神经细胞需氧量较大,代谢较活跃有关。     

Neural and behavioral plasticity associated with the transition from controlled to escalated cocaine use.

BACKGROUND: Rats given extended access to cocaine develop several symptoms of addiction, including a gradual escalation of drug intake, whereas rats given limited access do not. We asked here whether extended access to cocaine also produces drug-induced sensitization, a form of neurobehavioral plasticity implicated in addiction. METHODS: Rats were given limited (1 hour/session) or extended access (6 hours/session) to self-administered cocaine. Following a period of abstinence, rats were selected at random for assessment of their psychomotor response to cocaine or drug-seeking during extinction or for anatomic studies. RESULTS: When re-exposed to cocaine, rats allowed extended drug access showed greater drug-seeking behavior and were hypersensitive (sensitized) to the psychomotor activating effects of cocaine compared with rats given limited access. Extended access to cocaine was also associated with a greater increase in the density of dendritic spines on neurons specifically in the core of the nucleus accumbens (and not in the shell or medial or orbital frontal cortex). CONCLUSIONS: The transition from stable to escalated cocaine use, a hallmark of addiction, is associated with especially robust behavioral sensitization and synaptic reorganization in the core of the nucleus accumbens.     

Cerebellar grafting in the oculomotor system as a model to study target influence on adult neurons

In the last decades, there have been many efforts directed to gain a better understanding on adult neuron–target cell relationships. Embryonic grafts have been used for the study of neural circuit rewiring. Thus, using several donor neuronal tissues, such as cerebellum or striatum, developing grafted cells have been shown to have the capability of substituting neural cell populations and establishing reciprocal connections with the host. In addition, different lesion paradigms have also led to a better understanding of target dependence in neuronal cells. Thus, for example, axotomy induces profound morphofunctional changes in adult neurons, including the loss of synaptic inputs and discharge alterations. These alterations are probably due to trophic factor loss in response to target disconnection. In this review, we summarize the different strategies performed to disconnect neurons from their targets, and the effects of target substitution, performed by tissue grafting, upon neural properties. Using the oculomotor system—and more precisely the abducens internuclear neurons—as a model, we describe herein the effects of disconnecting a population of central neurons from its natural target (i.e., the medial rectus motoneurons at the mesencephalic oculomotor nucleus). We also analyze target-derived influences in the structure and physiology of these neurons by using cerebellar embryonic grafts as a new target for the axotomized abducens internuclear neurons.