Lymphocytes infiltrating the CNS during inflammation display a distinctive phenotype and bind to VCAM-1 but not to MAdCAM-1

The nature of inflammatory lymphocytes recruited to the CNShas been studied in a model of chronic inflammation. Injectionof killed Corynebacterlum parvum into the cortex of the mousebrain produces a circumscribed inflammatory cellular infiltratearound the injection site, and recruited mononuclear inflammatorycells (IC) can be isolated for flow cytometric analysis. Themajority of IC were T cells. In comparison with the predominantnaive population of mesenteric lymph node T cells, IC T cellsexpress much higher levels of CD44, LFA-1 and ICAM-1, and lowerlevels of CD45RB, features commonly associated with memory (previouslyactivated) cells. In addition, in contrast to the L-selectin⁺6-integrin^low phenotype of naive lymph node T cells, IC T cellslacked L-selectin and were 6-integrin^–. Mac-1, recentlyproposed as another marker of memory T cell differentation,was not displayed by IC T cells, suggesting that Mac-1 expressionmay be heterogeneous among memory T cell subsets. A subset ofmesenteric lymph node (MLN) T cells, probably representing activatedT cells undergoing the naive to memory transition, but not ofIC T cells, expressed high levels of 6-, ß7- and E-integrin.IC and MLN naive T cells expressed comparable levels of 4-integrin,but IC T cells stain poorly with anti-ß7 mAbs andwith mAb DATK 32, specific for the 4ß7 heterodimericlymphocyte homing receptor for the mucosal addressin MAdCAM-1,suggesting that these inflammatory cells express more 4ß1than 4ß7. Consistent with this, in in vitro adhesionassays, brain IC bound better than MLN cells to the 4ß1integrin ligand VCAM-1 and the LFA-1 ligand ICAM-1 but adheredvery poorly to the 4ß7 ligand MAdCAM-1. These findingsare consistent with and extend previous immunohistological studiesof T cells in murine experimental autoimmune encephalomyelitis,and demonstrate a distinctive phenotype for lymphocytes beingpresent in the chronically inflamed brain.     

Recovered memories of abuse in women with documented child sexual victimization histories

This study provides evidence that some adults who claim to have recovered memories of sexual abuse recall actual events that occurred in childhood. One hundred twenty-nine women with documented histories of sexual victimization in childhood were interviewed and asked about abuse history. Seventeen years following the initial report of the abuse, 80 of the women recalled the victimization. One in 10 women (16% of those who recalled the abuse) reported that at some time in the past they had forgotten about the abuse. Those with a prior period of forgetting—the women with recovered memories—were younger at the time of abuse and were less likely to have received support from their mothers than the women who reported that they had always remembered their victimization. The women who had recovered memories and those who had always remembered had the same number of discrepancies when their accounts of the abuse were compared to the reports from the early 1970s.     

老年学习记忆减退大鼠空间参考记忆和工作记忆能力的改变

目的　探讨老年学习记忆损害鼠空间学习记忆能力的改变特征。方法　用改良Morris 水迷宫检测40 只老年SD 大鼠(24m) 的空间学习记忆能力,按通用标准将其分为老年学习记忆减退组和老年学习记忆正常组,与青年组对照,检测其空间参考记忆和空间工作记忆能力。结果　老年学习记忆损害大鼠的行为学改变特征为:1) 简单学习记忆任务的学习能力没有明显变化。2) 空间参考记忆能力明显减退,寻找平台所用的游泳时间(ST) ,40cm 环内游泳时间(A40T) 和平台跨越次数(PC) 是反映老年学习记忆害大鼠空间参考记忆能力的理想指标。3) 空间工作记忆能力减退不明显。结论　A40T,PC 是反映空间参考记忆能力的敏感指标,ST 结合A40T 可筛选出理想的老年学习记忆减退动物模型。     

重度颅脑损伤病人康复期智力和记忆力及情感变化

目的探讨重度颅脑损伤病人康复期智力、记忆力及情感等方面的改变。②方法根据格拉斯哥昏迷指数（ＧＣＳ）所规定的等级,对４１例重度颅脑损伤病人进行智力、记忆力能力测验,并与我国常模比较。③结果康复优良组病人的操作智商、语言商数均在正常范围。重残组７５．０％的病人语言商数明显降低,３６．８％轻残组病人和１００％重残病人操作智商降低。④结论严重颅脑损伤病人存在着智力、记忆力和情感障碍,重度残疾病人以操作智商降低为主,康复优良病人常出现智力与记忆力缺陷。     

苯妥英钠对小鼠急性低压缺氧学习记忆障碍的影响

将40只体重20～24g昆明种小鼠随机分为4组,在建立急性低压缺氧导致小鼠学习记忆障碍模型基础上,采用跳台和避暗两种实验方法观察了苯妥英钠(DPH)对小鼠学习记忆障碍的影响.结果表明,急性低压缺氧(8km,停留30min)可导致小鼠学习记忆障碍;灌服DPH(40mg/kg)有一定的防治作用.     

纳络酮用于改善小鼠学习记忆障碍的研究

采用口服氯化铝建立小鼠学习记忆障碍模型,应用跳台法观察了纳络酮对铝(Al)中毒所致小鼠学习记忆障碍的改善作用,用火焰原子吸收分光光度法测定血锌(Zn)、铜(Cu)、锰(Mn)等含量.结果显示,氯化铝可导致小鼠学习记忆障碍,且有降低血Zn、Cu含量的作用(P<0.05);纳络酮治疗有改善Al中毒小鼠学习记忆障碍的作用,同时也增加了血Zn、Cu的含量.     

人参茎叶中二醇组皂甙对小鼠学习记忆及铜、锌、锰含量的影响

采用跳台法、火焰原子吸收分光光度计法分别研究了人参茎叶中二醇组皂甙(PDS)对小鼠学习记忆和全血铜(Cu)、锌(Zn)、锰(Mn)微量元素含量的影响. 结果表明,不同给药剂量各实验组小鼠跳台错误次数明显低于对照组(P<0.01),潜伏期明显延长(P<0.01);各实验组全血Cu含量均高于对照组(P<0.01),而Zn含量没有变化(P>0.05),Mn含量随给药剂量增加而增高,提示PDS具有提高小鼠学习记忆作用,可能与Cu、Mn含量增高有关.     

Reduction of tumorigenicity by an interferon-γ-gene-transduced tumor on another syngeneic tumor in a murine model

To evaluate the effect of interferon-γ-genetransduced cells, DS mice were inoculated into their footpads with syngeneic mammary adenocarcinoma SC42 admixed with interferon-γ producing mammary adenocarcinoma SC115Kγ, which had been established by an interferon-γ-gene transduction in another syngeneic mammary adenocarcinoma SC115 using retroviral vectors. These mice rejected both tumor cells and developed resistance to subsequent challenges with either SC115 or SC42 cells inoculated into their opposite posterior footpads. These results thus indicate that systemic immunological memory to each of the independent tumor cell lines developed in these mice. Although the SC42 cells admixed with irradiated SC115Kγ cells were rejected by these mice, the SC42 cells admixed with irradiated SC115neoR, in which the neo-gene had been transduced, were observed to proliferate. Tumor rejection was reversed by an in vivo administration of anti-interferon-γ antibody, thus suggesting that locally produced interferon-γ plays an important role in tumor elimination and immunological memory induction. In conclusion, interferon-γ-gene-transduced tumor cells are therefore considered to have a therapeutic potential for other types of malignant tumor cell lines.     

Hypermnesia in unilateral neglect

Thirteen right brain-damaged patients who were found to neglect pictures presented on the left of a display were presented the same stimuli, intermixed with foils, in a yes-no recognition test. Fifty per cent of patients claimed to have already seen one or more of the previously neglected pictures. This demonstrates that visual information that fails to access consciousness in neglect patients does retain the ability to surface as explicit memory at a later stage.     

Hypothesized neural dynamics of working memory: several chunks might be marked simultaneously by harmonic frequencies within an octave band of brain waves

The capacity of working memory (WM) for up to about seven simple items holds true both for humans and other species, and may depend upon a common characteristic of mammalian brains. This paper develops the conjecture that each WM item is represented by a different brain wave frequency. The binding-by-synchrony hypothesis, now being widely investigated, holds that the attributes of a single cognitive element cohere because electroencephalogram (EEG) synchrony temporarily unifies their substrates, which are distributed among different brain regions. However, thought requires keeping active more than one cognitive element, or WM "chunk," at a time. If there is indeed a brain wave frequency code for cognitive item-representations that are copresent within the same volume of neural tissue, the simple mathematical relationships of harmonies could provide a basis for maintaining distinctness and for orderly changes. Thus, a basic aspect of music may provide a model for an essential characteristic of WM. Music is a communicative phenomenon of "intermediate complexity," more highly organized than the firing patterns of individual neurons but simpler than language. If there is a distinct level of neural processing within which the microscopic physiological activity of neurons self-organizes into the macroscopic psychology of the organism, it might require such moderate complexity. Some of the obvious properties of music--orderly mixing and transitions among limited numbers of signal lines-are suggestive of properties that a dynamic neural process might need in order to organize and reorganize WM markers, but there are a number of additional, nonobvious advantageous properties of summating sinusoids in music-like relationships. In particular, harmonies register a stable periodic signal in the briefest possible time. Thus, the regularity of summating sinusoids whose frequencies bear harmony ratios suggests a particular kind of tradeoff between parallel and serial processing. When there are few copresent waves, at EEG frequencies, this sort of parallel coding retains behaviorally meaningful brief periods. A necessary companion hypothesis is that the brain wave frequencies underlying WM are confined to a single octave; that is, the upper and lower bounds of the band are in the ratio of 2:1. This hypothesized restriction, suggested by an empirical property of EEG bands that has been widely reported but rarely commented upon, has the important property of precluding spurious difference rhythms. A restriction to an octave, of "harmonious" frequency-markers for WM items, also seems consistent with a great deal of behavioral data suggesting that WM comprises a rapidly fading trace process in which only up to three or four item-representations are strongly activated simultaneously. There is also an additional, sequential renewal-or-revision process, within which up to another three or four items are being actively refreshed by rehearsal or replaced. Such serial processing may involve a less stringent octave band crowding problem.