奥明格健脑口服液改善小鼠记忆的作用

目的观察奥明格健脑口服液对改善小鼠记忆作用的影响。方法断乳小鼠，体重１２～１４ｇ，每组１４～１６只。把实验动物随机分为正常对照组、高剂量组、中剂量组和低剂量组，连续给样３０ｄ，进行跳台和水迷宫试验，以上试验按同样方法重复一次。结果两次小鼠实验表明，灌胃奥明格健脑口服液１ｍｏ后，跳台试验中受电击动物数和错误总数，各试验组均低于对照组，其中高剂量试验组显著低于对照组，而且潜伏期显著延长。水迷宫试验中，动物到达终点所需时间和错误总数，高中剂量组试验组均显著低于对照组。结论奥明格健脑口服液具有改善动物记忆的作用。     

Memory outcome at 5 years post-childhood traumatic brain injury

Primary objective: This study seeks to extend previous findings by documenting memory performance in a sample of 70 children at 5 years post-injury. It was anticipated that increasing injury severity would be associated with decreased performance on working and complex memory tasks. It was also expected that injury severity would significantly predict memory, but that the time from insult to subsequent testing would be associated with an increased relationship to non-injury factors.

Research design: Participants were assessed at 5 years post-injury, aged between 6-14 years, using measures of immediate, working and complex memory.

Methods and procedures: The sample comprised 18 children who had sustained a severe TBI, 24 with a moderate TBI, 11 with a mild TBI and 17 healthy controls, matched for age, gender and socio-economic-status.

Results: Results indicated that severe TBI was associated with decreased complex auditory-verbal memory performance, although children with TBI did not display impairment on immediate, working or complex visual-spatial memory. While injury severity significantly predicted complex memory outcome, non-injury factors failed to significantly predict either working or complex memory performance.

Conclusions: Future research should be engineered towards further clarifying what influences recovery from childhood TBI in the elongated post-injury period.     

Learning and sexual deficiencies in transgenic mice carrying a chimeric vasoactive intestinal peptide gene

The molecular mechanisms responsible for behavior are largely unknown. A state of the art model, paving the path from genes to behavior, is offered by transgenic animals. Candidate molecules are classic neuropeptides, such as vasoactive intestinal peptide (VIP). Transgenic mice harboring a chimeric VIP gene driven by the polyoma promoter were produced. Behavioral studies revealed learning impairment and prolonged retardation in memory acquisition in the genetically altered animals. Furthermore, reduced performance was observed when the male transgenic mice were tested for sexual activity in the presence of receptive females. Surprisingly, radioimmunoassays showed an approx 20% decrease in the VIP content of the transgenic mice brains. To directly assess genetically reduced VIP content as a cause for learning impairment, transgenic mice carrying diphtheria toxia-encoding sequences driven by the rat VIP promoter were created. These animals had reduced brain VIP and exhibited deficiencies in learning abilities, strongly supporting an important neurobiological function for VIP in vivo.     

A learned odor decreases the number of Fos-immunopositive granule cells in the olfactory bulb of young rats

Olfactory stimulation evokes a column of activity within the olfactory bulb extending from the glomerular layer to the granule cell layer that can be visualized with 2-deoxyglucose autoradiography, optical imaging, Fos protein immunohistochemistry and c-fos mRNA in situ hybridization. The Fos response to odors is typified by the activity of relatively few juxtaglomerular cells, which often occur in foci, and a large number of granule cells extending through much of the bulb. In this study, we characterized the granule cell response to an odor for which young rats had acquired a preference. Fos-like immunoreactive granule cells were quantified by image analysis, and densely stained cells were counted in a region previously shown to be responsive to peppermint odor. We found that odor-trained pups have about half the number of Fos-immunopositive superficial granule cells which respond to a learned odor than do control pups. We then determined whether there was a correlation between the juxtaglomerular cell response and the response of the superficial granule cells deep to those glomerular layer cells. We found a positive correlation between the number of juxtaglomerular cells and the number of granule cells demonstrating Fos immunoreactivity in both control and trained pups, a relationship that changed with early olfactory training.     

Peripheral clonal deletion of antiviral memory CD8+ T cells

Antiviral cytotoxic memory CD8⁺ T cells adoptively transferred to mice which are persistently infected with lymphocytic choriomeningitis virus WE or DOCILE initially proliferated extensively; they either caused the death of the recipient or, alternatively, disappeared within a few days. Apparently, the complete and coordinated induction and stimulation by widely distributed viral antigen caused these memory T cells to die before virus had been eliminated from the host. Thus memory T cells are as susceptible to peripheral exhaustion/deletion as unprimed T cells. These results indicate possible limitations of exclusively CD8⁺ T cell-mediated adoptive immunotherapy against viral infections or tumors.     

Expression of c-fos, fos B, and egr-1 in the medial preoptic area and bed nucleus of the stria terminalis during maternal behavior in rats

The spatial and temporal pattern of expression of the protein products of immediate early genes (IEGs) c-fos, fos B, and egr-1 were mapped in medial preoptic area (MPOA) and ventral bed nucleus of stria terminalis (VBST) during maternal behavior in rats. Immunocytochemical analysis indicated significant increases in the number of cells expressing c-Fos after 2 h of pup exposure, while Fos B levels showed a delayed response, reaching maximal levels after 6 h.     

Specific modulation of social memory in rats by cholinomimetic and nootropic drugs,by benzodiazepine inverse agonists,but not by psychostimulants

The recognition of an unfamiliar juvenile rat by an adult rat has been shown to imply short-term memory processes. In this study the effect of various psychotropic drugs on this investigatory behaviour was examined. The procedure was as follows: an unfamiliar juvenile rat was placed in the home cage of an adult rat for 5 min. The time spent by the adult rat in investigating the juvenile was recorded. The adult rat was then immediately treated with vehicle or test compounds, and was again exposed for 5 min to the same juvenile 2 h later. At this time point vehicle-treated rats no longer recognized the juvenile rat, i.e. the time of investigation was similar to that observed during the first presentation. Arecoline (1 and 3 mg/kg IP), physostigmine (0.05 and 0.1 mg/kg SC), RS86 (0.5 mg/IP) and nicotine (0.125 and 0.5 mg/kg IP) reduced in a dose-dependent fashion the time spent in investigating the juvenile during the second exposure. This result cannot be attributed to nonspecific effects, since it was not observed when a different juvenile was used for the second exposure. The effect of arecoline was reversed by scopolamine, but not by methylscopolamine. Aniracetam reduced investigatory behaviour at the dose of 50 mg/kg IP. FG 7142 (5 mg/kg IP) and -CCM (0.4 mg/kg IP) were also active and their effect was reversed by Ro 15-1788. dl-Amphetamine (0.5 and 1 mg/kg IP), nomifensine (1.25–10 mg/kg IP) and strychnine (0.25 and 0.5 mg/kg IP) were ineffective or reduced this behaviour unspecifically. Social recognition may therefore represent a useful and simple test to detect compounds which enhance short-term, olfactory, memory and to assess in the same animals the specificity of this activity.     

Incomplete effector/memory differentiation of antigen-primed CD8+ T cells in gene gun DNA-vaccinated mice

DNA vaccination is an efficient way to induce CD8+ T cell memory, but it is still unclear to what extent such memory responses afford protection in vivo. To study this, we induced CD8+ memory responses directed towards defined viral epitopes, using DNA vaccines encoding immunodominant MHC class I-restricted epitopes of lymphocytic choriomeningitis virus covalently linked to beta2-microglobulin. This vaccine construct primed for a stronger recall response than did a more conventional minigene construct. Despite this, vaccinated mice were only protected against systemic infection whereas protection against the consequences of peripheral challenge was limited. Phenotypic analysis revealed that DNA vaccine-primed CD8+ T cells in uninfected mice differed from virus-primed CD8+ T cells particularly regarding expression of very-late antigen (VLA)-4, an adhesion molecule important for targeting T cells to inflammatory sites. Thus, our DNA vaccine induces a long-lived memory CD8+ T cell population that provides efficient protection against high-dose systemic infection. However, viral replication in solid non-lymphoid organs is not curtailed sufficiently fast to prevent significant virus-induced inflammation. Our results suggest that this is due to qualitative limitations of the primed CD8+ T cells.     

妊娠中晚期暴露于可卡因对子代海马发育的影响

目的　建立妊娠中晚期暴露于可卡因的小鼠动物模型 ,研究可卡因对子代海马的发育是否具有影响以及这种影响在可卡因诱发的神经行为异常发病机理中可能所起的作用。方法　运用水迷宫方法观察可卡因对子鼠青春期空间辨别能力的影响 ,分别采用甲苯胺蓝染色技术和免疫组织化学结合图象分析技术观察海马中锥体细胞和神经胶质细胞的发育情况。结果　妊娠中晚期暴露于可卡因的小鼠子代在青春期海马锥体细胞极性紊乱 ,发育不良 ,未迁移到正常位置 ;神经胶质细胞数目减少。水迷宫结果显示可卡因可引起子代寻找平台的潜休期延长。结论　妊娠中晚期暴露于可卡因可引起子代青春期海马发育异常 ,这可能在可卡因引起子代空间辨别能力下降的发病机理中起着重要作用。