胚胎脊髓移植对大鼠脊髓全横断后功能修复及NOS表达的影响

目的　探讨胚胎脊髓移植对脊髓全横断大鼠脊髓功能修复及NOS表达的影响。方法　在脊髓全横断处移植胚胎脊髓 6 0d后 ,应用NADPH d组织化学方法检侧脊髓内一氧化氮合酶神经元的分布及形态变化 ,并做图像分析。用BBB评分法观察大鼠后肢运动功能的恢复。结果　胚胎大鼠脊髓移植后可以使全横断脊髓前角内NOS表达增加 ,与损伤对照组比较有显著性差异 (P <0 .0 1) ;大鼠后肢的自主运动功能恢复好于损伤对照组。结论　胚胎脊髓移植对成年大鼠损伤脊髓功能恢复有促进作用 ,NO可能参与修复作用。     

KA对原代培养胎鼠皮层神经元的毒性作用

目的探讨KA的神经毒性作用所引起神经元的损伤性改变。方法原代培养SD胎鼠皮层神经元,以不同浓度的KA分别作用12h、24h,用MTT检测法、显微镜形态学观察等方法进行研究。结果KA对神经元的毒性作用主要表现为神经元胞质空泡化,随着KA浓度的增加和作用时间的延长,其对神经元的细胞生长抑制率均增加(P<0.05)。结论KA对皮层神经元的毒性作用主要表现为以胞质空泡化为特征的类坏死样改变。     

大鼠臂旁核内nNOS阳性传入纤维的脑内来源

目的探讨大鼠臂旁核(PBN)内神经元型一氧化氮合酶(nNOS)阳性传入纤维的脑内来源。方法在大鼠PBN内微量注射荧光金(FG),结合nNOS免疫荧光双标技术,观察FG/nNOS双标神经元在脑内的分布情况。结果FG/nNOS双标神经元主要分布在孤束核(NST)、延髓嘴侧腹外侧区(RVL)、中缝背核(DR)、导水管周围灰质(PAG)和下丘脑室旁核(PVN)。结论NST、RVL、DR、PAG和PVN内的nNOS阳性投射神经元是PBN内nNOS阳性纤维终末的主要来源。     

大鼠脊髓向中央颈核和外侧颈核的投射——PHA-L顺行追踪研究

将菜豆白细胞凝集素(PHA-L)分别注入下颈髓、胸髓、腰髓和骶髓等不同脊髓节段,顺行追踪脊髓向中央颈核和外侧颈核的投射。观察结果表明,脊髓不同节段注入PHA-L,在中央颈核和外侧颈核均可见到标记末梢;比较各节段脊髓的投射分布,未能发现明显的定位关系。一侧脊髓灰质注入,在两侧中央颈核均观察到标记末梢,但主要见于同侧;外侧颈核的标记末梢仅见于同侧。结果提示,各节段脊髓均发出纤维投射到同侧中央颈核和外侧颈核。     

家兔大脑、小脑和顶盖向脊髓直接投射的研究

将辣根过氧化物酶(HRP)分别注入家兔脊髓单侧的颈、胸和腰等不同节段,逆行追踪大脑、小脑和顶盖向脊髓的直接投射。结果表明,大脑皮质的HRP标记神经元仅见于C_(2-7)注入例动物;小脑中央核的标记神经元仅见于C_(2-4)注入例动物;顶盖上丘的标记神经元仅见于C_(2、3)注入例动物;而均未见于胸腰段注入例动物。标记神经元主要分布于注入侧的对侧。本研究确信,由大脑皮质发出的皮质脊髓束投射到脊髓C_(1-7)节段;由小脑中央核发出的小脑脊髓束投射到脊髓C_(1-4)节段,由顶盖发出的顶盖脊髓束投射到脊髓C_(1-3)节段。     

大鼠和小鼠胚胎后肾移植的形态学研究

目的观察不同胚龄的大鼠和小鼠的后肾植入同种异体远交系成年宿主体内后的生长变化,探讨胚胎后肾移植的最佳胚龄及血管起源。方法应用光、电镜及免疫组织化学技术观察不同胚龄的后肾移植后,肾脏各部的发育情况及后肾内CD31+阳性细胞的分布。结果离体后肾移植10天后成熟的肾小体形成,胚龄16天的大鼠和胚龄13天的小鼠后肾移植10天后,排斥反应轻微;胚龄20天的大鼠后肾和胚龄14、16天的小鼠后肾移植10天后,出现明显排斥反应,且随着胚龄的增长排斥反应逐渐加重。CD31+阳性细胞分布在肾小体毛细血管内皮及部分皮质中的间质细胞。结论胚龄16天的大鼠和胚龄13天的小鼠后肾中均无成熟肾小体出现,是移植的最佳时间;后肾移植物内的毛细血管袢是由移植物的间质细胞分化而来的。     

Personality and Individual Differences in Spinal Motoneuronal Excitability

Although individual differences in sensation-seeking are characterized by a wide range of differences in the expression of motor behavior, the psychophysiological correlates of these characteristics have not been extensively explored. In the present investigation the response characteristics of compound muscle action potentials, the H-reflex and associated motor responses, were examined in young adult subjects who were administered the Sensation Seeking Scale (Zuckerman, 1979) and the Eysenck Personality Questionnaire (Eysenck & Eysenck, 1975). Variations in reflex responses were observed using two independent procedures. A paired stimulus method assessed the extent of reflex amplitude recovery at varying pulse intervals. A second method, termed homosynaptic depression, examined motoneuronal excitability in response to trains of pulses delivered at varying rates. The personality groups did not differ with respect to the intensity of stimulation required to elicit muscle action potentials or the nerve conduction velocities of those potentials. High disinhibition and high extraversion groups displayed reduced motoneuronal excitability as assessed by analysis of reflex recovery functions. For extraversion, similar effects were observed with the homosynaptic depression measure. These results demonstrate that individual differences in disinhibition and extraversion can be referred to discrete levels of CNS motor system activity. In this context, stimulus seeking behavior is not distinguished by a need for stimulation (initial hypoexcitability) but reflects instead reduced motor excitability which becomes evident once motoneuronal activity is initiated.     

The Effects of Long-Term Spinal Cord Injury on Mechanical Properties of the Rat Urinary Bladder

We have demonstrated that bladder wall tissue in spinal cord injury (SCI) rats at 10 days post-injury is more compliant and accompanied by changes in material class from orthotropic to isotropic as compared to normal tissue. The present study examined the long-term effects (3-, 6-, and 10-weeks) post-SCI on the mechanical properties of bladder wall tissues, along with quantitative changes in smooth muscle orientation and collagen and elastin content. Bladder wall compliance (defined as det(F) − 1 under an equi-biaxial stress state of 100 kPa, where F is the deformation gradient tensor) was found to be significantly greater at 3- and 6-weeks (0.873 ± 0.092 and 0.864 ± 0.112, respectively) when compared to the normal bladders (0.260 ± 0.028), but at 10 weeks the compliance reduced (0.389 ± 0.061) to near that of normal bladders. This trend in mechanical compliance closely paralleled the collagen/elastin ratio. Moreover, changes in material class, assessed using a graphical technique, correlated closely with quantitative changes in smooth muscle fiber orientation. The results of the present study provide the first evidence that, while similarities exist between acute and chronic responses of the urinary bladder wall tissue to SCI, the overall alterations are distinct, result in profound and complex time dependent changes in bladder wall structure, and will lay the basis for simulations of the bladder wall disease process.     

Astrogliogenesis in Heterotopic Allotransplants of Rat Embryonic Neocortex

We studied gliogenesis in transplants of rat embryonic neocortex (E14-15) in 3, 7, 15, and 30 days and 12-13 months after transplantation into the sciatic nerve of adult animals. Immunogistochemical reactions to intermediate filament proteins nestin, vimentin, glial fibrillary acidic protein were used. In transplants, vimentin- and nestin-positive precursor cells differentiate into astrocytes earlier that in the developing rat neocortex (in situ). One year after transplantation, some astrocytes start to express nestin and vimentin, which attests to the development of reactive gliosis in the transplants.     

大鼠颈髓中央核向前庭神经外侧核的定位纤维投射

目的　探讨大鼠颈髓中央核向前庭神经外侧核的定位投射。方法　本实验通过向脊髓内单侧注射菜豆—白细胞凝集素 ,在不同节段上对由脊髓向前庭神经核的纤维投射做顺行示踪。结果　在颈髓颈 2和颈 3节段包括颈髓中央核单侧注射示踪剂后 ,应用免疫组织化学法在对侧前庭神经下核以及前庭神经内侧核的大型细胞、小型细胞部和尾部内可见大量标记终末。在对侧前庭神经外侧核由头部至尾部整个范围内 ,标记物数量最多 ;在颈膨大处单侧注射示踪剂后 ,在对侧前庭神经内侧核的大型细胞部见很多标记轴突和终末 ,但在前庭神经外侧核和前庭神经下核内 ,仅见少量标记轴突和终末。在颈膨大以下脊髓节段注射示踪剂后 ,在前庭神经内侧核的大型细胞部、前庭神经下核及前庭神经外侧核的尾部标记纤维和终末仅零星存在。结论　颈部初级传入纤维经过颈中央核中继后 ,可直接投射到对侧前庭神经外侧核 ,同时 ,研究结果亦提示颈髓中央核可能是颈部传入冲动的中继和整合之处     

Facilitation from Contralateral Primary Afferents of Interneuronal Transmission in the la Inhibitory Pathway to Motoneurones

The action of volleys in contralateral primary afferents on transmission in the la inhibitory pathways to motoneurones was investigated with intracellular recording from motoneurones. Ia IPSPs in flexor as well as most extensor motoneurones were regularly facilitated by volleys in contralateral high threshold muscle, cutaneous and joint afferents in spinal cats under chloralose anaesthesia. In decerebrate cats with a low pontine lesion transmission in la inhibitory pathways was not facilitated but rather depressed by volleys in these afferents. The recurrent effects from motor axon collaterals were investigated on inhibitory transmission from different contralateral afferents to motoneurones. Previous investigations have shown that the interneurones mediating the reciprocal la inhibition receive recurrent inhibition via motor axon collaterals and Renshaw cells. Now a strong positive correlation was revealed between recurrent depression of IPSPs evoked from different contralateral afferents and facilitation of la IPSPs by the same afferent volleys. These results suggest that the recurrent depression of IPSPs from different contralateral primary afferents depends on their excitatory convergence onto the la inhibitory interneurones, which then partly mediate the IPSP evoked in the motoneurone from these afferents.     

X线照射致胚胎大鼠皮质内结构异常

目的探讨胚胎期X线照射引起大鼠皮质内异常结构的形成机理。方法选取妊娠14日(E14)大鼠接受X线(剂量为1.0Gy)照射。采用HE染色、Fluoro Jade B染色及增殖细胞核抗原(PCNA)抗体免疫组化染色观察胚脑的皮质构筑。结果HE染色观察到E14大鼠接受X线照射后大量细胞脱落入侧脑室并在2日后完全清除,Fluoro Jade B染色显示此脱落细胞为阳性。E16及E18的皮质内出现玫瑰环样结构及脑室区的凹陷,且PCNA阳性细胞表达于玫瑰环样结构及脑室区凹陷的细胞株。结论E14大鼠受X线照射可引起广泛的大脑皮质细胞构筑异常和细胞增殖。     

Therapeutic Effect of Curcumin and Methylprednisolone in the Rat Spinal Cord Injury

In addition to imperiling an individual's daily life, spinal cord injury (SCI), a catastrophic medical damage, can permanently impair an individual's body function. Methylprednisolone (MP), a medically accepted therapeutic drug for SCI, is highly controversial for the lack of consensus on its true therapeutic effect. In recent years, curcumin has served as a potential and novel therapeutic drug in SCI. Our study was intended to investigate the precise effect of MP and curcumin in SCI. We examined the function of MP and curcumin in a SCI model rat, both in vivo and in vitro, and found that there was a momentous improvement in Basso‐Beattie‐Bresnahan scores in the MP‐treated group when compared with Cur‐treated group within 14 days. Results obtained from the histological, immunohistochemistry and ultrastructural examinations evidenced the curative effect of MP was better than curcumin before Day 14. Nonetheless, there was a significant variation in the treatment effect between the MP‐treated and Cur‐treated groups after 14 days. The curcumin's effectiveness was more obvious than MP after 14 days following SCI. As such, we surmise that curcumin has a better therapeutic potential than MP with a prolong treatment time in the wake of SCI. Anat Rec, 301:686–696, 2018. © 2017 Wiley Periodicals, Inc.