Co-localization of vasoactive intestinal polypeptide, γ-aminobutyric acid and choline acetyltransferase in neocortical interneurons of the adult rat

Interneurons immunoreactive for vasoactive intestinal polypeptide (VIP) are integral elements of columnar organization patterns in the rat cerebral cortex. By application of the sensitive mirror technique, the co-localization of VIP with the classical inhibitory neurotransmitter γ-aminobutyric acid (GABA) and the acetylcholine-synthesizing enzyme, choline acetyltransferase (ChAT), was investigated in neocortical neurons. Furthermore, the frequency of co-localization of ChAT with GABA was determined. In a sample of 118 VIP-immunoreactive neurons, mostly from the primary somatosensory cortex, it was demonstrated that virtually all of them reveal immunoreactivity for GABA and, therefore, are to be GABAergic. Moreover, 34% of mostly bipolar, VIP-positive neurons contained ChAT and are, thus, supposedly cholinergic as well. Co-localization of VIP and ChAT varied according to cortical laminae. Finally, 88% of a total of 60 ChAT-immunoreactive neurons were also immunostained for GABA. It is concluded that almost all VIP-immunoreactive neurons and most of the cholinergic neurons in rat neocortex represent partly overlapping subpopulations of inhibitory interneurons utilizing GABA.     

Role of intracortical mechanisms in the late part of the silent period to transcranial stimulation of the human motor cortex

Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the human motor cortex produce a silent period (SP) following motor evoked potentials (MEPs). The early part of the SP can be explained by decreased alpha motor neuron excitability, whereas the late part is presumably due to suprasegmental mechanisms. In order to determine the level of the suprasegmental contribution to the generation of SPs, we recorded excitatory and inhibitory responses to TMS, TES, and percutaneous electrical brainstem stimulation (PBS) in the voluntarily activated first dorsal interosseous muscle of the hand. Stimulus intensities were set so that PBS and TES induced MEPs with areas equal to or larger than those of MEPs obtained with TMS. This procedure revealed that SPs were 49% and 83% shorter with TES and PBS, respectively, than with TMS. As TMS is more effective than TES or PBS in activating cortical interneurons, these findings support the idea that a significant component of the SP arises from intracortical mechanisms.     

缺氧缺血性脑病新生鼠补钙前后脑细胞,红细胞内外钙的变化

为了观察一般剂量补钙对缺氧缺血性脑病（ＨＩＥ）脑细胞和红细胞内外钙变化的影响，以探讨ＨＩＥ时补钙是否增加脑细胞钙超载，用ＨＩＥ新生动物模型进行了实验研究，结果表明：（１）缺氧缺血时红细胞、脑细胞及脑组织出现钙积聚；（２）补钙后，血浆总钙浓度明显升高，而脑细胞、脑组织及红细胞钙积聚并未加重；（３）血浆总钙浓度与脑细胞或红细胞胞浆游离钙离子浓度无相关关系。提示：（１）ＨＩＥ时钙内流可能是全身性的；（２）对ＨＩＥ并低钙血症患儿吸氧后一般剂量补钙可能是安全的。     

Figure-Ground Segregation at Contours: a Neural Mechanism in the Visual Cortex of the Alert Monkey

An important task of vision is the segregation of figure and ground in situations of spatial occlusion. Psychophysical evidence suggests that the depth order at contours is defined early in visual processing. We have analysed this process in the visual cortex of the alert monkey. The animals were trained on a visual fixation task which reinforced foveal viewing. During periods of active visual fixation, we recorded the responses of single neurons in striate and prestriate cortex (areas V1, V2, and V3/V3A). The stimuli mimicked situations of spatial occlusion, usually a uniform light (or dark) rectangle overlaying a grating texture of opposite contrast. The direction of figure and ground at the borders of these rectangles was defined by the direction of the terminating grating lines (occlusion cues). Neuronal responses were analysed with respect to figure-ground direction and contrast polarity at such contours. Striate neurons often failed to respond to such stimuli, or were selective for contrast polarity; others were non-selective. Some neurons preferred a certain combination of figure-ground direction and contrast polarity. These neurons were rare both in striate and prestriate cortex. The majority of neurons signalled figure-ground direction independent of contrast polarity. These neurons were only found in prestriate cortex. We explain these responses in terms of a model which also explains neuronal signals of illusory contours. These results suggest that occlusion cues are used at an early level of processing to segregate figure and ground at contours.     

羧乙基锗倍半氧化物对大鼠脑缺血再灌注损伤的保护作用

采用结扎双侧颈总动脉后再通的方法复制大鼠脑缺血再灌注损伤模型，通过测定再灌注后大鼠海马组织中脂质过氧化产物丙二醛（ＭＤＡ），超氧化物歧化酶（ＳＯＤ）与谷胱甘肽过氧化物酶（ＧＳＨ—Ｐｘ）及ＡＴＰａｓｅ的活性，观察了有机锗─羧乙基锗倍半氧化物（ＣＧＳ）对大鼠脑缺血再灌注后大鼠海马组织中ＭＤＡ水平，明显保护ＳＯＤ、ＧＳＨ─Ｐｘ、Ｎａ＋Ｋ＋─ＡＴＰａｓｅ及Ｃａ２＋─ＡＴ─Ｐａｓｅ活性。表明ＣＧＳ对大鼠脑缺血再灌注损伤具有保护作用。     

加锌对大鼠脑内微量元素的影响

用SD雌性成年大鼠20只,随机分为实验组和对照组各10只。加锌40d后,用原子吸收分光光度计(日本津岛)分别测定了两组大鼠大脑皮质感觉运动区和海马CA3区的微量元素Zn、Cu、Fe和轻金属Mg的含量。结果表明:在大脑皮质感觉运动区,两组大鼠的诸元素含量无显著变化;在海马CA3区,两组大鼠的微量元素Zn、Cu、Fe的含量也无显著变化(P>0.05),但轻金属Mg的含量却发生了显著的变化,表现为对照组明显高于实验组(P<0.05)。     

Statistical analysis of gait patterns of persons with cerebral palsy

Patients at Boston's Children's Hospital diagnosed as having cerebral palsy were filmed walking. These films were digitized and translated into measurements associated with leg motion. In this paper we use the gait measurements of 128 such patients to illustrate that the kth nearest neighbour clustering procedure results in a gait typology for patients with cerebral palsy. The procedure identifies four subpopulations from the sample data; the membership of a patient within this typology is mostly determined by the patient's motor control. The developed typology differs from the present diagnostic system which classifies a cerebral palsy patient as either quadriplegic, diaplegic or hemiplegic.     

Innervation of the zona fasciculata of the adult human adrenal cortex: a light and electron microscopic study

Summary Autonomic innervation of the adrenal cortex has been demonstrated in several species. Detailed ultrastructural studies on the innervation of the zona fasciculata of the normal human adrenal cortex are lacking. We report herein our observations on the pattern of innervation of the cells of the zona fasciculata of the normal adult human cortex at both the light and electron microscope levels. Postganglionic unmyelinated fibers were observed to descend from a dense capsular meshwork and to be distributed as delicate branches among the columns of endocrine cells. Immunoperoxidase staining confirmed the presence of nerve fibers in the zona fasciculata in a distribution similar to that observed after staining with silver impregnation methods. Ultrastructural findings lent further support to these observations by the demonstration of bundles of unmyelinated fibers with focal enlargements containing terminal boutons with both clear and dense core vesicles in close approximation with the endocrine cells.     

老年脑梗死患者急性期血小板活化功能定量检测

目的 :探讨老年脑梗死患者外周血中血小板膜糖蛋白变化的临床意义。　方法 :应用流式细胞术检测了 6 8例急性期老年脑梗死患者外周血血小板活化分子标记物CD4 1、CD6 2p和CD6 3的含量水平 ,与 4 2例正常老年人对照 ;并对脑梗死组病灶大小、梗死部位、病情分级等与血小板活化分子表达的变化进行分析 ,应用统计学进行处理。　结果 :急性期脑梗死患者血小板粘附分子CD4 1、CD6 2 p和CD6 3的表达水平显著高于正常对照组 (P <0 .0 1) ,且与梗死灶大小及病情分级密切相关 ,与梗死部位无关。　结论 :老年脑梗死患者急性期外周血血小板活化功能明显增强 ,为早期应用抗血小板聚集药物的治疗提供了实验依据     

大鼠皮质神经元的体外培养和纯化

目的：探讨大鼠皮质神经元分离纯化的有效方法。方法：取胎鼠大脑皮质细胞，分别在不同的培养液中进行原代培养，利用相差显微镜对培养的细胞进行动态观察；并以免疫细胞化学技术对神经元进行染色。结果：在相差显微镜下可见加用N2添加剂和胎牛血清培养的神经元生长良好，胞体形态多样，突起数目多，长度长，与邻近神经元的胞体或突起形成接触，而胶质细胞则大量死亡，神经元纯化率达94％以上，未加用N2添加剂培养的神经元胶质细胞大量存在，神经元纯化率达50％左右。结论：N2添加剂和胎牛血清联合应用可使大鼠皮质神经元得到良好的生长和有效纯化。