穹隆-海马伞切断对大鼠脑内不同部位胆碱乙酰化转移酶表达的影响

①目的　观察穹隆 海马伞切断对大鼠脑内不同部位胆碱乙酰化转移酶 (ChAT)表达的影响 ,探讨与学习、记忆相关的机制。②方法　成年健康雌性Wistar大鼠 ,随机分为穹隆 海马伞切断模型组和假手术组 ,各 5只。在脑立体定位仪上切断双侧穹窿 海马伞 ,建立动物模型。假手术组除不切断海马伞外 ,其余步骤同模型组。ChAT免疫细胞化学染色。观察海马CA1区、皮质区、杏仁复合体区、基底前脑Meynert核等部位ChAT阳性细胞表达变化。③结果　假手术组大脑各观察区有基础水平的ChAT表达。模型组大脑海马CA1区皮质、大脑皮质区、杏仁复合体区以及Meynert核区ChAT阳性细胞数明显减少 ,与假手术组比较差异有显著性 (t =7.713～17.16 6 ,P <0 .0 1)。④结论　穹隆 海马伞切断大鼠脑内多部位ChAT表达减少可能是学习、记忆障碍原因之一。     

新生豚鼠海马神经干细胞的分离培养及鉴定

目的：探讨新生豚鼠海马来源的神经干细胞体外培养的最佳条件。方法：分离新生24h内的豚鼠海马组织，制成单细胞悬液，分别于DMEM／F12培养基、含体积分数2％B27的培养基及含4ng／L bFGF的B27培养基进行原代和传代培养，收集原代和传代培养的细胞，进行巢蛋白(Nestin)、GFAP及NSE免疫细胞化学染色。结果：在含bFGF的B27培养基中，传代的细胞不断分裂增殖，形成悬浮生长的呈Nestin阳性的神经干细胞团。传代培养分化的细胞可见NSE或GFAP免疫阳性细胞。结论：含体积分数2％B27的DMEM／F12培养基中添加bFGF可获得大量新生豚鼠海马神经干细胞。     

Habituation of human limbic neuronal response to sensory stimulation

Hippocampal, parahippocampal gyrus, and amygdalar neuronal responses to visual and acoustic stimuli were analyzed during trains of several hundred stimulus repetitions as part of an investigation of sensory pathways to medial temporal lobe structures in complex-partial epilepsy patients who were being monitored with depth electrodes. Ten percent of more than 500 single and multiple units tested were responsive to simple sensory stimuli. The majority of the responsive units were recorded in the posterior parahippocampal gyrus (HG) during visual stimulation. Although neurons in pes hippocampi (PH; Ammons's horn) were also responsive to photic stimuli, no visually responsive units were found in amygdala. Very few units were responsive to acoustic stimuli, and these were found only in PH and amygdala, and not in HG. Significant trends of increase or decrease in response amplitude during trains of stimuli were found in all acoustically responsive units. Significant trends of visual response amplitude increase or decrease were found in 20% of PH units, and in 44% of HG units. Mean latencies of acoustically responsive units were longer than those of visually responsive units, and latencies of PH sensory units showing decremental response were longer than nondecremental PH units. Rate of response decrement was usually linear for acoustic responses and exponential for visual responses. The response dynamics of medial temporal lobe neurons are compared with those described in the animal limbic system and are related to habituation of human sensory evoked scalp potentials.     

Adenomatoid tumor of the fimbrial endosalpinx: report of two cases with discussion of histogenesis.

Two asymptomatic cases of adenomatoid tumor, confined to the lamina propria of the tubal fimbria, are presented, and their location within strictly Müllerian territory is offered as indirect evidence for the Müllerian origin of this lesion. To stress the individuality of this distinct entity, the name of Müllerian mesothelioma is suggested.     

Amygdaloid efferents through the stria terminalis in the rat give origin to zinc-containing boutons

Many regions of the basal forebrain are innervated by zinc-containing axonal boutons. In the present work, the lesion/degeneration method, coupled with histochemical staining for zinc-containing boutons, was used to determine the origins and efferent pathways of these zinc-containing projections to the basal forebrain. Knife cuts of the stria terminalis or extensive electrolytic lesions of the amygdala resulted in the bleaching of the staining for zinc (Timm stain) and terminal degeneration (Fink-Heimer method) ipsilaterally in the following areas: granule cell layer of the accessory olfactory bulb, shell of nucleus accumbens, bed nucleus of the stria terminalis, striohypothalamic nucleus, retrochiasmatic area, ventromedial hypothalamic nucleus (in the cell-sparse shell), medial tuberal nucleus, terete hypothalamic nucleus, and ventral premammillary nucleus. Small lesions made with ibotenic acid in the posteromedial part of the amygdalohippocampal area caused bleaching of the stain for zinc in the accessory olfactory bulb, in the medial zone of the bed nucleus of the stria terminalis, and in the ventral premammillary nucleus. Lesions in either the ventral subiculum or the anterolateral part of the amygdalohippocampal area caused bleaching in the ventromedial hypothalamic nucleus. Lesions in the hippocampus or in the neocortex did not produce bleaching of the stain for zinc in the above-mentioned terminal fields. The present results agree with previous studies on amygdaloid efferents and suggest that neurons in the amygdalohippocampal area and, possibly, in the ventral subiculum give origin to zinc-containing boutons.     

Delayed NGF infusion fails to reverse axotomy-induced degeneration of basal forebrain cholinergic neurons in adult p75(LNTR)-deficient mice

The p75 low-affinity neurotrophin receptor (p75^LNTR) appears to have various functions that include enhancing nerve growth factor (NGF)-mediated survival by increasing TrkA (high-affinity NGF receptor) efficiency, and mediating apoptosis by acting as a ligand-regulated pro-apoptotic receptor. Here, we investigated the role of p75^LNTR for adult cholinergic basal forebrain neurons by comparing neuronal responses to injury in control and p75^LNTR-deficient mice. In both types of mice, 70% of the cholinergic neurons in the ipsilateral medial septum had lost their markers choline acetyltransferase and tyrosine kinase A by 28 days following unilateral transection of the dorsal septohippocampal pathway (fimbria fornix). A 7-day delayed infusion of NGF that started 28 days after the injury resulted in reversal of choline acetyltransferase expression and cell atrophy in control, but not in p75^LNTR-deficient, mice. This lack of response to delayed NGF treatment in p75^LNTR-deficient mice was most likely not due to cell death, as all of the septohippocampal neurons, labeled with Fluorogold before the lesion, were present at 28 days post-lesion, similar to control mice. p75^LNTR-deficient cholinergic neurons can respond to NGF as they were protected by NGF infusions that started immediately after the injury. These observations, the fact that lesioned p75^LNTR-deficient neurons atrophy faster, and that non-lesioned neurons hypertrophy in response to NGF in control but not in p75^LNTR-deficient mice, suggest that p75^LNTR is needed for tyrosine kinase A and NGF signaling efficiency.

In conclusion, during adulthood p75^LNTR appears to play a beneficial role in the response of cholinergic neurons to injury, consistent with the proposed role of p75^LNTR in the enhancement of TrkA signaling and the transport of neurotrophins by these neurons.     

大鼠双侧海马伞离断对脂多糖诱导的下丘脑催产素能神经元功能活动的影响

为观察去海马传入对免疫应激时下丘脑室旁核、视上核催产素能神经元功能活动的影响 ,以探索海马调控外周免疫反应的脑内环路 ,本研究预先切断大鼠双侧海马伞 ,2 8d后腹腔内注射细菌内毒素脂多糖 (lipopolysaccharide,LPS,75 0μg/kg) ,用免疫组织化学双标记方法 ,以 F os蛋白作为神经元功能活动的标记物 ,观察下丘脑催产素能神经元中即刻早期基因的表达变化。结果显示 :双侧海马伞离断后 ,下丘脑室旁核中因腹腔脂多糖刺激而发生活化的催产素能神经元活化百分率显著下降 ;而视上核中催产素能神经元的活化未受明显影响。上述结果表明 ,海马对下丘脑 -垂体 -肾上腺轴以及免疫系统的抑制作用部分是通过其支配的下丘脑室旁核的催产素能神经元来完成的。     

Distribution of the pilS gene in Escherichia coli pathovars,its transfer ability and influence in the typical enteropathogenic E. coli adherence phenotype

Typical enteropathogenic Escherichia coli strains (tEPEC) cause attaching/effacing lesions in eukaryotic cells and produce the bundle-forming pilus (BFP), which interweaves and aggregates bacteria, resulting in the localized adherence (LA) pattern on eukaryotic cells. Previously, we identified tEPEC strains (serotype O119:H6) that exhibited LA simultaneously with an aggregative adherence (AA)-like pattern (LA/AA-like+). Remarkably, AA is characteristically produced by strains of enteroaggregative E. coli (EAEC), another diarrheagenic E. coli pathovar. In one LA/AA-like?+?strain (Ec404/03), we identified a conjugative plasmid containing the pil operon, which encodes the Pil fimbriae. Moreover, a pil operon associated with an AA pattern and plasmid transfer had been previously described in the EAEC C1096 strain. In this study, we investigated the occurrence of the two pilS alleles (pilS_Ec404 and pilS_C1096) in tEPEC strains of different serotypes, origins and years of isolation. We also examined the potential relationship of pilS with the AA-like phenotype, its ability to be transferred by conjugation, and occurrence among strains of the other E. coli pathovars. The pilS alleles were found in 90 (55.2%) of 163 tEPEC strains, with pilS_Ec404 occurring more often (30.7%) than pilS_C1096 (25.1%). About 21 tEPEC serotypes carried pilS. The pilS alleles were found in tEPEC strains from Chile, Peru and different Brazilian cities, with the oldest strain being isolated in 1966. No absolute correlation was found between the presence of pilS and the AA-like pattern. Conjugative pilS transfer was detected in 26.2% of pilS_Ec404+ strains and in 65.1% of pilS_C1096+ strains, but only pilS_Ec404+ transconjugants were AA-like+, thus suggesting that the latter allele might need a different genetic background to express this phenotype. pilS was found in all other E. coli pathovars, where it was most prevalent in enterotoxigenic E. coli. More studies are needed to understand the mechanisms involved in the regulation of Pil expression and production.