全球大气二氧化碳浓度升高对植物的影响

全球大气二氧化碳浓度升高对植物的影响蒋高明（中国科学院植物研究所,北京１０００４４）ＴＨＥＩＭＰＡＣＴＯＦＧＬＯＢＡＬＩＮＣＲＥＡＳＩＮＧＯＦＣＯ＿２ＯＮＰＬＡＮＴＳＪｉａｉｎｇＧａｏ－ｍｉｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＢｏｔａｎｙ,Ａｃａｄｅｍｉａ,...     

KF核及B(o)tzinger复合体内GABA能神经元向膈神经核的投射

实验在６只成年猫上进行。将ＷＧＡ－ＨＲＰ微量注入Ｃ５膈神经核内,通过逆行追踪及ＧＡＢＡ免疫组织化学ＦＩＴＣ荧光双重标记方法,研究了脑干内ＧＡＢＡ能神经元向膈神经核的投射。结果在脑桥ＫＦ核和面神经后核周围区（即Ｂｏｔｚｉｎｇｅｒ复合体）观察到ＧＡＢＡ－ＨＲＰ双标神经元。另外,在中缝大核、旁巨细胞外侧核及前庭神经核也观察到双标神经元。本实验结果表明：发自上述脑干神经核团,特别是ＫＦ核及Ｂｏｔｚｉｎｇｅ     

人主动脉硫酸乙酰肝素蛋白聚糖对培养的人血管壁细胞生长的作用

通过培养的人主动脉平滑肌细胞（ｈＡＳＭＣ）及脐静脉内皮细胞（ｈＵＶＥＣ）,应用３Ｈ－ＴｄＲ参入、Ｎｏｒｔｈｅｒｎｂｌｏｔ分析、逆转录多聚酶链反应（ＲＴ－ＰＣＲ）、放射免疫分析（ＲＩＡ）、和紫外比色法等技术观察了人主动脉中硫酸乙酰肝素蛋白聚糖（ＨＳＰＧ）对ｈＡＳＭＣ和ｈＵＶＥＣＤＮＡ合成的作用及对血小板源生长因子（ＰＤＧＦ）、ＰＤＧＦ受体、转化生长因子β（ＴＧＦ－β）、内皮素－１（ＥＴ－１）或碱性成纤维细胞生长因子（ｂＦＧＦ）基因表达和肾素－血管紧张系统（ＲＡＳ）的影响,结果显示,ＨＳＰＧ明显抑制培养的ｈＡＳＭＣ基础的ＤＮＡ合成（ｃｐｍ值为：１０３８５±３２６３ｖｓ,２５５４１±６４２１,Ｐ＜０．０１）及外源性ＰＤＧＦ诱导的ＤＮＡ合成（ｃｐｍ值为：９８７８±１９４７ｖｓ．１３４８１±４４ｌ０,Ｐ＜０．０５）;抑制ＰＤＧＦＡ链、ＴＧＦ－Ｂｐ和ＥＴ－１ｍＲＮＡ表达,提高ＰＤＧＦａ和β受体ｍＲＮＡ的表达;显著降低ｈＡＳＭＣ培养液中血管紧张素Ⅱ（ＡｎｇⅡ）的浓度和血管紧张素转换酶（ＡＣＥ）的活性,推测ＨＳＰＧ抑制ＰＤＧＦＡ链、ＴＧＦ－β及ＥＴ－１ｍＲＮＡ表达,降低ＡＣＥ活性及ＡｎｇⅡ浓度是其抑制ｈＡＳＭＣ增殖的重要机     

炎症介质对离体大鼠肠系膜动脉降钙素基因相关肽释放的影响

本工作目的是在离体大鼠肠系膜动脉床灌流模型上,观察几种常见炎症介质：前列腺素Ｅ２（ＰＧＥ２）、缓激肽（ＢＫ）、组胺（ＨＩＳ）、血小板活化因子（ＰＡＦ）及５－羟色胺（５－ＨＴ）对血管周围感觉神经介质ＣＧＲＰ释放的直接影响。结果显示：ＰＧＥ２（１－１００μｍｏｌ／Ｌ）和ＢＫ（５－１０μｍｏｌ／Ｌ）能引起大鼠肠系膜动脉床时间和浓度依赖性地释放ＣＧＲＰ。ＨＩＳ,ＰＡＦ和５－ＨＴ则未见明显作用。结果提示,ＰＧＥ２与ＢＫ可能是引起血管周围感觉神经兴奋和ＣＧＲＰ释放的主要炎症介质。     

DDPH对猪肺动脉平滑肌细胞PDGF·BB和bFGF表达的影响：免疫细胞化学研究

ＤＤＰＨ［１－（２．６－二甲基苯乙氧基）－２－（３．４二甲氧基苯乙胺基）丙烷盐酸盐］是南京药科大学合成的降压新化合物,也具有降低肺动脉高压和抑制肺动脉平滑肌细胞增殖作用。本实验用细胞培养、免疫细胞化学、图像分析、３Ｈ－ＴｄＲ、细胞周期测定等方法,进一步探讨ＤＤＰＨ对缺氧性肺动脉平滑肌细胞（ＰＡＳＭＣＳ）增殖的抑制机制。结果：缺氧促进肺动脉内皮细胞（ＰＡＥＣｓ）的ＰＤＧＦ·ＢＢ和ｂＦＧＦ两种生长因子的表达（积分光密度ＯＤ值）增高。缺氧内皮细胞条件培养液（ＨＥＣＣＭ）能促进ＰＡＳＭＣＳ的ＰＤＧＦ·ＢＢ的ＯＤ值增高,ｂＦＧＦ的ＯＤ值无明显改变。加药组（ＨＥＣ－ＣＭ＋ＤＤＰＨ）的ＰＤＧＦ·ＢＢ和ｂＦＧＦ的ＯＤ值均显著降低,尤以ＰＤＧＦ·ＢＢ的ＯＤ值减少最多．提示：ＤＤＰＨ能抑制ＨＥＣＣＭ引起ＰＡＳＭＣＳ的ＰＤＧＦ·ＢＢ和ｂＦＧＦ表达增多和细胞增殖。结果与大鼠实验观察相符。     

杏仁核内注射CCK—8抑制胃运动的机制

应用脑核团内微量注射和核团电刺激方法,观察杏仁基底内侧（ＢＭＡ）对胃运动的影响,分析ＢＭＡ与下丘脑腹内侧核（ＶＭＨ）的机能联系。结果如下：（１）双侧ＢＭＡ内注射八肽胆囊收缩素（ＣＣＫ－８）（５０ｎｇ／ｌμｌ）,出现胃内压（ＩＧＰ）和胃运动频率（ＧＭＦ）显著下降（Ｐ〈０．０１）。（２）ＢＭＡ内注射ＣＣＫ－Ａ受体阻断剂［Ｌ３６４,７１８］（１００ｎｇ／ｌμｌ）或ＣＣＫ－Ｂ受体阻断剂［Ｌ３６５,２６０］     

猕猴F2及F4区皮层神经元在图形引导的有序运动中放电活动的比较

用细胞外记录的方法研究了猕猴在执行图形辨认引导的有序运动（ＦＲＳ）时大脑皮层弓形沟距周围背外侧运动前皮层（ＰＭｄ）Ｆ２区和腹外侧运动前皮层（ＰＭｖ）Ｆ４区的放电活动在ＦＲＳ的暗示期,Ｆ２和Ｆ４区中分别有５２％（３９／７５）和１６．９％（１３／７７）的细胞发生放电变化;在触摸反应期,各有５１％（３８／７５）和８７％（６７／７７）的细胞发生放电变化,经统计检验,均有显著差异。Ｆ２区比Ｆ４区有更多细胞对     

CRF在谷氨酸兴奋中央杏仁核引起的升压反应中之作用

促肾上腺皮质激素释放因子（ＣＲＦ）能神经元的胞体和轴突末梢广泛分布在中央杏仁核（ＡＣ）及其投射的重要升压区。本工作显示：（１）谷氨酸兴奋ＡＣ或将ＣＲＦ分别注入ＡＣ投射区：室旁核（ＮＰＶ）、外侧下丘脑／穹窿周围区（ＬＨ／ＰＦ）、蓝斑（ＬＣ）、臂旁核（ＮＰＢ）、中脑导水管周围灰质（ＰＡＧ）或延髓头端腹外侧区（ＲＶＬ）均引起升压反应;（２）ＡＣ的上述投射区内预先分别注入α－ＨｅｌｉｃａｌＣＲＦ［９－４１］（ＣＲＦ拮抗剂）均能阻断谷氨酸兴奋ＡＣ引起的升压反应。以上结果结合以往报道：ＬＨ／ＰＦ也有纤维投射至ＬＣ、ＮＰＢ和ＰＡＧ,后三者均可通过ＲＶＬ引起升压反应,表明ＡＣ发出的ＣＲＦ能投射纤维一方面可兴奋ＮＰＶ,另一方面则可间接（通过ＬＨ／ＰＦ）或直接作用于ＬＣ、ＮＰＢ和ＰＡＧ,进而激活ＲＶＬ－交感兴奋神经元,也可能直接兴奋ＲＶＬ而引起升压反应     

用Bac-to-Bac杆状病毒表达系统高效表达绿色荧光蛋白标记的HBVe抗原

通过基因工程操作,使乙型肝炎病毒ｅ抗原（ＨＢｅＡｇ）基因与绿色荧光蛋白基因（ＧＦＰ）融合,用新型Ｂａｃ－ｔｏ－Ｂａｃ杆状病毒表达系统在昆虫细胞中高效表达了ＨＢｅＡｇ－ＧＦＰ双功能融合蛋白。经ＥＬＩＳＡ法和荧光显微镜观察证实,表达产物既能发射易于检测的绿色荧光,又具有ＨＢＶ的ｅ抗原活性,为免疫诊断新方法的建立进行了有益的探索     

用Bac—to—Bac杆状病毒表达系统高效表达绿色荧光蛋白标记的HBVe抗原

通过基因工程操作,使乙型肝炎病毒ｅ抗原（ＨＢｅＡｇ）基因与绿色荧光蛋白基因（ＧＦＰ）融合,用新型Ｂａｃ－ｔｏ－Ｂａｃ杆状病毒表达系统在昆虫细胞中高效表达了ＨＢｅＡｇ－ＧＦＰ双功能融合蛋白。经ＥＬＩＳＡ法和荧光显微镜观察证实,表达产物既能发射易于检测的绿色荧光,又具有ＨＢＶ的ｅ抗原活性,为免疫诊断新方法的建立进行了有益的探索。     

Suppressing Emotions Impairs Subsequent Stroop Performance and Reduces Prefrontal Brain Activation

Abundant behavioral evidence suggests that the ability to self-control is limited, and that any exertion of self-control will increase the likelihood of subsequent self-control failures. Here we investigated the neural correlates underlying the aftereffects of self-control on future control processes using functional magnetic resonance imaging (fMRI). An initial act of self-control (suppressing emotions) impaired subsequent performance in a second task requiring control (Stroop task). On the neural level, increased activity during emotion suppression was followed by a relative decrease in activity during the Stroop task in a cluster in the right lateral prefrontal cortex (PFC) including the dorsolateral prefrontal cortex (DLPFC), an area engaged in the effortful implementation of control. There was no reliable evidence for reduced activity in the medial frontal cortex (MFC) including the anterior cingulate cortex (ACC), which is involved in conflict detection processes and has previously also been implicated in self-control. Follow-up analyses showed that the detected cluster in the right lateral PFC and an area in the MFC were involved in both the emotion suppression task and the Stroop task, but only the cluster in the right lateral PFC showed reduced activation after emotion suppression during the Stroop task. Reduced activity in lateral prefrontal areas relevant for the implementation of control may be a critical consequence of prior self-control exertion if the respective areas are involved in both self-control tasks.     

猴运动前区皮层神经元在顺序行为中的放电活动

本工作猴运动前区（ＰＭ）皮层神经元在视觉图表引导的有序运动行为中的放电活动,并在与记忆信息完成的空间顺序行为（ＭＳＳ）中的活动作了比较。为为训练三只猴同时学会ＦＲＳ和ＭＳＳ任务。对１１１个神经元的统计分析表明,它们在ＦＲＭＳ和ＭＳＳ暗示期中发生放电频率变化的均有一半以上。反应期里有放电频率变化的比例也很高;图形期里,ＦＲＳ中的比例比ＭＳＳ中的高出很多。它们对不同运动顺序呈现明显的选择性。对在动物完     

衰老对大鼠脑区氨基酸水平的影响

本文测定了正常青龄组（３月龄）和老龄组（２０月龄）大鼠不同脑区（皮层、小脑海马、纹状体和下丘脑）谷氨酸、天门冬氨酸、甘氨酸、ｒ－氨基丁酸和牛磺酸的含量。结果表明：在衰老过程中大鼠某些脑区谷氨酸、天门冬氨酸、甘氨酸和牛磺酸水平显著降低;而纹状体γ－氨基丁酸含量则显著升高。     

Top-down control-signal dynamics in anterior cingulate and prefrontal cortex neurons following task switching

The prefrontal cortex (PFC) and anterior cingulate cortex (ACC) have both been implicated in cognitive control, but their relative roles remain unclear. Here we recorded the activity of single neurons in both areas while monkeys performed a task that required them to switch between trials in which they had to look toward a flashed stimulus (prosaccades) and trials in which they had to look away from the stimulus (antisaccades). We found that ACC neurons had a higher level of task selectivity than PFC neurons during the preparatory period on trials immediately following a task switch. In ACC neurons, task selectivity was strongest after the task switch and declined throughout the task block, whereas task selectivity remained constant in the PFC. These results demonstrate that the ACC is recruited when cognitive demands increase and suggest a role for both areas in task maintenance and the implementation of top-down control.     

Prefrontal neurons predict choices during an auditory same-different task

The detection of stimuli is critical for an animal's survival [1]. However, it is not adaptive for an animal to respond automatically to every stimulus that is present in the environment [2-5]. Given that the prefrontal cortex (PFC) plays a key role in executive function [6-8], we hypothesized that PFC activity should be involved in context-dependent responses to uncommon stimuli. As a test of this hypothesis, monkeys participated in a same-different task, a variant of an oddball task [2]. During this task, a monkey heard multiple presentations of a "reference" stimulus that were followed by a "test" stimulus and reported whether these stimuli were the same or different. While they participated in this task, we recorded from neurons in the ventrolateral prefrontal cortex (vPFC; a cortical area involved in aspects of nonspatial auditory processing [9, 10]). We found that vPFC activity was correlated with the monkeys' choices. This finding demonstrates a direct link between single neurons and behavioral choices in the PFC on a nonspatial auditory task.     

Amino acid neurotransmitter alterations in three sublines of Rb mice differing by their susceptibility to audiogenic seizures

The levels of inhibitory amino acids (Tau, Gly), or excitatory amino acids (Glu, Asp) and Gln, precursor of GABA, have been determined, under resting conditions, in 17 brain areas of 3 sublines of inbred Rb mice displaying different responses to an acoustic stimulus. Rb1 mice were clonictonic seizure-prone, Rb2 mice were clonic seizure-prone and Rb3 mice were seizure resistant. Profile of distribution in the brain of each one of these amino acids differed. Maximum to minimum level ratio was higher for Tau (3.8) than for Glu or Asp or Gln (2). The level of Gly was similar in 13 out of the 17 areas examined. Multiple inter-subline differences were recorded for each amino acid. These differences have been analyzed considering the seizure susceptibility or severity of the three Rb sublines. Common lower levels (approximately –20%: Rb1/Rb3, Rb2/Rb3) of Gln in Temporal Cortex may be implicated in seizure susceptibility. Seirure severity (Rb1/Rb2) seems to correlate, in some areas, with additional lower amounts of GABA already reported and, to a lower extent, of Asp (–19% in striatum, inferior colliculus and cerebellum), of Tau and Gly; a tendency for a rise in Gln content was observed in certain others (10–20% in olfactory bulb, thalamus, hypothalamus, substantia nigra, and frontal, temporal and occipital cortex). The data and correlations recorded provide guidelines for further investigations for synaptosomal and metabolic alterations in the three sublines of the same strain of Rb mice.Abbreviations used GABA 4-aminobutyrate - Tau taurine - Gly glycine - Asp aspartate - Glu glutamate - Gln glutamine - GEPR genetically epilepsy-prone rat - OB olfactory bulbs - OT olfactory tubercles - Sr striatum - Se septum - Hy hypothalamus - Hi hippocampus - Th thalamus - A amygdala - SC superior colliculus - IC interior colliculus - SN substantia nigra - FCx frontal cortex - TCx temporal cortex - OCx occipital cortex - C cerebellum - P pons - Ra raphe     

γ-Aminobutyric Acid and Glycine Modulate Each Other''s Release Through Heterocarriers Sited on the Releasing Axon Terminals of Rat CNS

The ability of gamma-aminobutyric acid (GABA) and glycine (Gly) to modulate each other's release was studied in synaptosomes from rat spinal cord, cerebellum, cerebral cortex, or hippocampus, prelabeled with [3H]GABA or [3H]Gly and exposed in superfusion to Gly or to GABA, respectively. GABA increased the spontaneous outflow of [3H]Gly (EC50, 20.8 microM) from spinal cord synaptosomes. Neither muscimol nor (-)-baclofen, up to 300 microM, mimicked the effect of GABA, which was not antagonized by either bicuculline or picrotoxin. However, the effect of GABA was counteracted by the GABA uptake inhibitors nipecotic acid and N-(4,4-diphenyl-3-butenyl)nipecotic acid. Moreover, the GABA-induced [3H]Gly release was Na+ dependent and disappeared when the medium contained 23 mM Na+. The effect of GABA was Ca2+ independent and tetrodotoxin insensitive. Conversely, Gly enhanced the outflow of [3H]GABA from rat spinal cord synaptosomes (EC50, 100.9 microM). This effect was insensitive to both strychnine and 7-chlorokynurenic acid, antagonists at Gly receptors, but it was strongly Na+ dependent. Also, the Gly-evoked [3H]GABA release was Ca2+ independent and tetrodotoxin insensitive. GABA increased the outflow of [3H]Gly (EC50, 11.1 microM) from cerebellar synaptosomes; the effect was not mimicked by either muscimol or (-)-baclofen nor was it prevented by bicuculline or picrotoxin. The GABA effect was, however, blocked by GABA uptake inhibitors and was Na+ dependent. Gly increased [3H]GABA release from cerebellar synaptosomes (EC50, 110.7 microM) in a strychnine- and 7-chlorokynurenic acid-insensitive manner. This effect was Na+ dependent. The effects of GABA on [3H]Gly release seen in spinal cord and cerebellum could be reproduced also with cerebrocortical synaptosomes.(ABSTRACT TRUNCATED AT 250 WORDS)     

A neural correlate of the processing of multi-second time intervals in primate prefrontal cortex

Several areas of the brain are known to participate in temporal processing. Neurons in the prefrontal cortex (PFC) are thought to contribute to perception of time intervals. However, it remains unclear whether the PFC itself can generate time intervals independently of external stimuli. Here we describe a group of PFC neurons in area 9 that became active when monkeys recognized a particular elapsed time within the range of 1-7 seconds. Another group of area 9 neurons became active only when subjects reproduced a specific interval without external cues. Both types of neurons were individually tuned to recognize or reproduce particular intervals. Moreover, the injection of muscimol, a GABA agonist, into this area bilaterally resulted in an increase in the error rate during time interval reproduction. These results suggest that area 9 may process multi-second intervals not only in perceptual recognition, but also in internal generation of time intervals.     

Hippocampal-prefrontal connectivity predicts midfrontal oscillations and long-term memory performance

The hippocampus and prefrontal cortex interact to support working memory (WM) and long-term memory [1-3]. Neurophysiologically, WM is thought to be subserved by reverberatory activity of distributed networks within the prefrontal cortex (PFC) [2, 4-8], which become synchronized with reverberatory activity in the hippocampus [1, 4]. This electrophysiological synchronization is difficult to study in humans because noninvasive electroencephalography (EEG) cannot measure hippocampus activity. Here, using a novel integration of EEG and diffusion-weighted imaging, it is shown that individuals with relatively stronger anatomical connectivity linking the hippocampus to the right ventrolateral PFC (ventral Brodmann area 46) exhibited slower frequency neuronal oscillations during a WM task. Furthermore, subjects with stronger hippocampus-PFC connectivity were better able to encode the complex pictures used in the WM task into long-term memory. These findings are consistent with models suggesting that electrophysiological oscillations provide a mechanism of long-range interactions [9] and link hippocampus-PFC structural connectivity to PFC rhythmic electrical dynamics and memory performance. More generally, these results highlight the importance of incorporating individual differences when linking structure and function to cognition.