Immunocytochemical detection of calcineurin and microtubule-associated protein 2 in central neurocytoma

Summary An immunohistochemical study was carried out on four cases of central neurocytoma, which had characteristic clinicopathological features including ultrastructural findings. Specific antibodies to calcineurin (CaN), microtubule-associated protein 2 (MAP2) and synaptophysin (SYP) were used. All tumor tissues examined showed specific immunoreactivity for CaN and MAP2. Immunolabelling of both molecules revealed that they were mainly localized in the perikarya and proximal processes of the tumor cells. SYP immunoreactivity was found in three of the four cases. SYP immunoreaction products were predominantly seen in the tumor cell processes, while the perikarya were weakly or moderately positive for SYP. The data suggest that CaN and MAP2, together with SYP, can be useful tools for identifying and characterizing of the central neurocytoma.     

天芪益智颗粒对阿尔茨海默病大鼠学习记忆能力和突触功能的影响

[目的] 研究天芪益智颗粒对阿尔茨海默病大鼠学习记忆能力及脑内突触素、微管相关蛋白-2（MAP-2）表达的影响。[方法] 采用侧脑室注射Aβ_1-42的方法建立动物模型,将90只SD大鼠随机分成模型组、假手术组、阳性药组（石杉碱甲）、天芪益智颗粒高、中、低剂量组,每组15只。连续给药30 d后,通过避暗实验评价大鼠的学习记忆能力,采用Western Blot方法测定大鼠脑内突触素、MAP-2.[结果] 与模型组相比,天芪益智颗各剂量组大鼠潜伏期长于模型组（P<0.01）,错误次数小于模型组（P<0.01）.模型组大鼠脑内突触素、MAP-2表达低于假手术组（P<0.01）,天芪益智颗粒各剂量组突触素、MAP-2表达高于模型组（P<0.01）.[结论] 天芪益智颗粒能改善阿尔茨海默病大鼠学习记忆能力,改善突触功能。     

Probiotics modulate the microbiota–gut–brain axis and improve memory deficits in aged SAMP8 mice

ProBiotic-4 is a probiotic preparation composed of Bifidobacterium lactis, Lactobacillus casei, Bifidobacterium bifidum, and Lactobacillus acidophilus. This study aims to investigate the effects of ProBiotic-4 on the microbiota–gut–brain axis and cognitive deficits, and to explore the underlying molecular mechanism using senescence-accelerated mouse prone 8 (SAMP8) mice. ProBiotic-4 was orally administered to 9-month-old SAMP8 mice for 12 weeks. We observed that ProBiotic-4 significantly improved the memory deficits, cerebral neuronal and synaptic injuries, glial activation, and microbiota composition in the feces and brains of aged SAMP8 mice. ProBiotic-4 substantially attenuated aging-related disruption of the intestinal barrier and blood–brain barrier, decreased interleukin-6 and tumor necrosis factor-α at both mRNA and protein levels, reduced plasma and cerebral lipopolysaccharide (LPS) concentration, toll-like receptor 4 (TLR4) expression, and nuclear factor-κB (NF-κB) nuclear translocation in the brain. In addition, not only did ProBiotic-4 significantly decreased the levels of γ-H2AX, 8-hydroxydesoxyguanosine, and retinoic-acid-inducible gene-I (RIG-I), it also abrogated RIG-I multimerization in the brain. These findings suggest that targeting gut microbiota with probiotics may have a therapeutic potential for the deficits of the microbiota–gut–brain axis and cognitive function in aging, and that its mechanism is associated with inhibition of both TLR4-and RIG-I-mediated NF-κB signaling pathway and inflammatory responses.     

Somatostatin varicosities contain the vesicular GABA transporter and contact orexin neurons in the hypothalamus

Somatostatin (SST) is a neuropeptide with known inhibitory actions in the hypothalamus, where it inhibits release of growth hormone‐releasing hormone (GHRH), while also influencing the sleep–wake cycle. Here we investigated in the rat whether SST neurons might additionally release GABA (gamma‐aminobutyric acid) or glutamate in different regions and whether they might contact orexin neurons that play an important role in the maintenance of wakefulness. In dual‐immunostained sections viewed by epifluorescence microscopy, we examined if SST varicosities were immunopositive for the vesicular transporter for GABA (VGAT) or glutamate (VGLUT2) in the posterolateral hypothalamus and neighboring arcuate nucleus and median eminence. Of the SST varicosities in the posterolateral hypothalamus, 18% were immunopositive for VGAT, whereas ≤ 1% were immunopositive for VGLUT2. In the arcuate and median eminence, 26 and 64% were VGAT+ and < 3% VGLUT2 + , respectively. In triple‐immunostained sections viewed by epifluorescence and confocal microscopy, SST varicosities were seen in contact with orexin somata, and of these varicosities, a significant proportion (23%) contained VGAT along with synaptophysin, the presynaptic marker for small synaptic vesicles, and a similar proportion (25%) abutted puncta that were immunostained for gephyrin, the postsynaptic marker for GABAergic synapses. Our results indicate that a significant proportion of SST varicosities in the hypothalamus have the capacity to release GABA, to form inhibitory synapses upon orexin neurons, and accordingly through their peptide and/or amino acid, to inhibit orexin neurons, as well as GHRH neurons. Thus while regulating GHRH release, SST neurons could serve to attenuate arousal and permit progression through the sleep cycle.     

Ontogeny of calbindin immunoreactivity in the human hippocampal formation with a special emphasis on granule cells of the dentate gyrus

Calbindin (CB) is a calcium-binding protein that is present in principal cells as well as in interneurons of the hippocampal formation of various species including humans. Studies with transgenic mice revealed that CB is essential for long-term potentiation and synaptic plasticity which are the cellular basis of learning and memory. In a previous study we have shown that CB expression in granule cells of the dentate gyrus correlates with the functional maturation of the hippocampal formation in the rat.     

丰富环境干预对孕期手机辐射暴露后仔鼠认知功能的影响

目的:探讨丰富环境干预对孕期长时间手机辐射暴露后仔鼠认知功能的影响。方法:18只SPF级SD孕鼠随机分为两组,分别给予对照处理(不辐射)、长时间手机辐射处理(辐射24 h/d,21d),待仔鼠出生后饲养至18月龄,进行丰富环境干预,共分为3组,分别为对照组(CON)、手机辐射组(PR)及丰富环境组(PR+EE)。于丰富环境干预28 d后应用Morris水迷宫评定仔鼠认知功能;免疫组化及Western Blot检测海马区突触素(SYN)和脑源性神经营养因子(BDNF)表达;透射电镜观察海马区突触的超微结构。结果:与CON组相比,PR组及PR+EE组仔鼠的逃避潜伏期延长,跨越平台的次数减少,SYN和BDNF表达均减少,海马CA1区超微结构改变;而与PR组相比,PR+EE组逃避潜伏期缩短,穿越平台次数增加,SYN和BDNF表达均上调,且SYN阳性细胞增多,海马CA1区突触超微结构改变。结论:丰富环境干预可能通过上调海马SYN和BDNF表达,改变突触超微结构,提高突触可塑性,进而改善孕期手机辐射暴露后仔鼠的认知功能。     

Endocrine Mucin-Producing Sweat Gland Carcinoma: An Uncommon Presentation

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare, often underrecognized, low-grade sweat gland carcinoma of the skin of the eyelid. To date, only 20 cases of this carcinoma have been reported, most frequently in Caucasian females with an average age of 70 years. Although the diagnosis is primarily made with immunohistochemical stain, compared to endocrine ductal carcinoma in situ, clinical detection serves as a potentially curative treatment. Further, its benign appearance clinically makes this tumor often misdiagnosed and undertreated. This disease commonly presents in Caucasian women of advanced age, aiding in the diagnosis of this tumor, which presents an even more critical diagnosis in a patient with a rare presentation. In the available literature, we could find no case of EMPSGC in younger African American women. The following case is the first case presented in the literature. Here, we present a case of an atypical presentation of the tumor in a young African American female, as well as a review of literature on the pathophysiology, clinical presentation, and treatment of EMPSGC.     

Behavior‐associated Neuronal Activation After Kainic Acid‐induced Hippocampal Neurotoxicity is Modulated in Time

Kainic acid‐induced (KA) hippocampal damage leads to neuronal death and further synaptic plasticity. Formation of aberrant as well as of functional connections after such procedure has been documented. However, the impact of such structural plasticity on cell activation along time after damage and in face of a behavioral demand has not been explored. We evaluated if the mRNA and protein levels of plasticity‐related protein synaptophysin (Syp and SYP, respectively) and activity‐regulated cytoskeleton‐associated protein mRNA and protein levels (Arc and Arc, respectively) in the dentate gyrus were differentially modulated in time in response to a spatial‐exploratory task after KA‐induced hippocampal damage. In addition, we analyzed Arc+/NeuN+ immunopositive cells in the different experimental conditions. We infused KA intrahippocampally to young‐adult rats and 10 or 30 days post‐lesion (dpl) animals performed a hippocampus‐activating spatial‐exploratory task. Our results show that Syp mRNA levels significantly increase at 10dpl and return to control levels after 30dpl, whereas SYP protein levels are diminished at 10dpl, but significantly increase at 30dpl, as compared to 10dpl. Arc mRNA and protein levels are both increased at 30dpl as compared to sham. Also the number of NeuN+/Arc+ cells significantly increases at 30dpl in the group with a spatial‐exploratory demand. These results provide information on the long‐term modifications associated to structural plasticity and neuronal activation in the dentate gyrus after excitotoxic damage and in face of a spatial‐exploratory behavior. Anat Rec, 300:425–432, 2017. © 2016 Wiley Periodicals, Inc.     

卡马西平对癫痫模型大鼠海马损伤作用及对Fascin-1、突触素表达的影响

目的研究卡马西平对癫痫模型大鼠海马损伤的作用及对肌成束蛋白(Fascin-1)、突触素(SYP)表达的影响。方法选择54只无特定病原体动物(SPF)级SD健康大鼠,选取40只建立癫痫模型,分为模型组、低剂量组、中剂量组、高剂量组,每组10只,另设10只正常大鼠为正常组。低剂量组、中剂量组、高剂量组分别给予卡马西平(质量浓度2 g/L)15 mg/kg、30 mg/kg、50 mg/kg进行治疗,采用脑电图机观察大鼠潜伏期、持续时间、波幅指标,统计发作次数、发作总时间,苏木精-伊红染色法(HE)染色处理,观察海马区细胞凋亡指数,采用蛋白质印迹法(Western Blot)检测Fascin-1、突触素、Bcl-2、Bax表达水平。结果模型组潜伏期及Fascin-1、Bcl-2表达水平低于正常组、低剂量组、中剂量组、高剂量组,持续时间、波幅、海马区细胞凋亡指数及突触素、Bax表达水平高于正常组、低剂量组、中剂量组、高剂量组,差异均有统计学意义(P<0.05)。卡马西平各剂量组潜伏期高于模型组,持续时间、波幅、海马区细胞凋亡指数低于模型组,差异具有统计学意义(P<0.05)。中剂量组潜伏期、Fascin-1、Bcl-2表达水平高于低剂量组和高剂量组,持续时间、波幅、发作次数、发作总时间、海马区细胞凋亡指数及突触素、Bax表达水平低于低剂量组和高剂量组,差异有统计学意义(P<0.05)。结论卡马西平能降低癫痫模型大鼠海马损伤程度,起到一定的抗癫痫作用,可能与调控Fascin-1、突触素、Bcl-2、Bax表达水平有关。     

Organ of Corti explants direct tonotopically graded morphology of spiral ganglion neurons in vitro

The spiral ganglion is a compelling model system to examine how morphological form contributes to sensory function. While the ganglion is composed mainly of a single class of type I neurons that make simple one‐to‐one connections with inner hair cell sensory receptors, it has an elaborate overall morphological design. Specific features, such as soma size and axon outgrowth, are graded along the spiral contour of the cochlea. To begin to understand the interplay between different regulators of neuronal morphology, we cocultured neuron explants with peripheral target tissues removed from distinct cochlear locations. Interestingly, these “hair cell microisolates” were capable of both increasing and decreasing neuronal somata size, without adversely affecting survival. Moreover, axon characteristics elaborated de novo by the primary afferents in culture were systematically regulated by the sensory endorgan. Apparent peripheral nervous system (PNS)‐like and central nervous system (CNS)‐like axonal profiles were established in our cocultures allowing an analysis of putative PNS/CNS axon length ratios. As predicted from the in vivo organization, PNS‐like axon bundles elaborated by apical cocultures were longer than their basal counterparts and this phenotype was methodically altered when neuron explants were cocultured with microisolates from disparate cochlear regions. Thus, location‐dependent signals within the organ of Corti may set the “address” of neurons within the spiral ganglion, allowing them to elaborate the appropriate tonotopically associated morphological features in order to carry out their signaling function. J. Comp. Neurol. 524:2182–2207, 2016. © 2015 Wiley Periodicals, Inc.