QUANTITATIVE HISTOCHEMISTRY OF GLUTAMATE DECARBOXYLASE IN THE RAT HIPPOCAMPAL REGION

Abstract— The distribution of glutamate decarboxylase (GAD) was studied in hippocampus regio superior and in area dentata. In both regions the enzyme showed a bimodal distribution profile with peak activities in the molecular and pyramidal layers of hippocampus, and in the molecular and granular layers of area dentata. The pyramidal and granular layers contain the terminals and perikarya of inhibitory intrinsic neurones, the basket cells. The molecular layers contain neurones of similar morphology but with unknown function. GAD showed a very low activity in fimbria, a major pathway of fibres efferent and afferent to the hippocampal region.
The data are consistent with GAD being concentrated within the inhibitory local neurones of the hippocampal region.     

大鼠海马CA3区的习得性长时程突触增强

本实验应用慢性埋植电极技术以电生理学结合行为学的方法,观察大鼠条件性饮水反应的建立、消退和再建立过程中,其海马CA_3区突触效应的变化规律。以刺激内嗅区的穿通纤维(PP)诱发的单突触的群体锋电位(PS)及群体兴奋性突触后电位(EPSPs)为指标,经叠加处理分析,发现随着条件反应的建立,海马CA_3锥体细胞出现突触效应的长时程增强(LTP),它随行为反应的实验性消退而消退,而在随后再次建立条件反应时,又重新出现;且无论此LTP达最高水平还是它的完全消退均超前于条件性行为反应的水平。又在一个实验日训练作业结束时PS并未立即随之增大,在24h内它随时间而发展,但到第4小时已达最高水平,且条件反应率是与PS的水平相应的,对PS与EPSPs的斜率进行相关分析表明,PS的变化主要是突触传递功效的变化。上述结果表明,海马CA_3区随着行为训练有习得性LTP产生。从其发神变化特点及其与条件性行为的关系,提示此习得性LTP极其可能是本实验中学习和记忆的展经基础。     

TOPOGRAPHICAL AND SUBCELLULAR LOCALIZATION OF CHOLINE ACETYLTRANSFERASE IN RAT HIPPOCAMPAL REGION

—Choline acetyltransferase (ChAc) was localized in discrete layers in hippocampus regio superior and in area dentata. The highest activity in hippocampus was found in a narrow infrapyramidal zone, but high activities were also observed in the rest of stratum oriens and in stratum pyramidale. In area dentata the highest activities were found in a narrow supragranular zone and in hilus fasciae dentatae. The localization corresponded very closely to that of acetylcholinesterase. The main part of ChAc activity was confined to the synaptosome fraction. The results are compatible with the view that pyramidal and granular cells are excited by cholinergic boutons, mainly located on the basal or apical dendrites near the somata.     

噪声对幼年和老年大鼠海马CA_3区习得性长时程突触增强的影响

经强噪声重复暴露(96 dB,2h/d,25 d)后,幼年和老年大鼠在条件反应的建立和再建立过程中,其海马CA_3区习得性长时程突触增强(LTP)的发展均受到明显阻抑,相应地动物达到学会标准需更多的训练。但幼年鼠受阻抑的程度更为严重。对习得性LTP的消退则在幼年和老年大鼠均无明显影响。本研究从突触功能的可塑性方面揭示幼年功物特别容易受到强噪声重复暴露的危害,提示应重视环境噪声对人类婴幼儿脑功能的损害作用的研究。     

RETURN OF THE PROSOBRANCH GIBBULA UMBILICALIS (DA COSTA) TO THE LITTORAL REGION AFTER DISPLACEMENT TO THE SHALLOW SUBLITTORAL

In experiments carried out on the trochid prosobranch gastropodGibbula umbilicalis (da Costa) in Lough Ine, Ireland, it wasshown that when this snail had been displaced to the shallowsublittoral region it moved directly towards its proper zonein the littoral region. It did this even though moved to a newsite at which the compass orientation of the shore was different.In further experiments it was attracted seawards to a blackplastic wall. We propose that it responds to a perception ofthe shore (or other dark objects) in the upper visual field.This explanation is compatible with the presence of statocystsand with the structure of the trochid eye. (Received 2 April 1984;     

ELEVATED CONCENTRATIONS OF HISTAMINE IN THE RAT BRAIN

—Whole brain concentrations of histamine (Hm) in the rat were measured with a sensitive and specific single-isotope enzymatic microassay and found to be elevated about 2-fold in rats killed by focused microwave irradiation compared with rats killed by decapitation. However, regardless of the method of killing, whole brain Hm concentrations were elevated about 4-fold when the brains were homogenized in 12.5 vol vs 2.5 vol of water or phosphate buffer. Homogenization of brain regions in 12.5 vol of water resulted in Hm concentrations that were about 10 times greater than previously reported values (except in the hypothalamus). Since (1) the‘extra’Hm could be extracted from pellets of low volume homogenates, and (2) synthesis of Hm is not likely to occur through an increase in the volume of water or buffer used for homogenization, we suggest that the elevated concentrations of Hm seen after high volume homogenization of brain tissue are due to a more complete extraction of Hm from brain tissue, and not to an artifactual production of this amine from its precursor (histidine) or some other compound(s).     

噪声对海马CA3区神经元电活动及突触超微结构的影响

本文用电生理学方法及电镜技术研究105dB(A)白噪声对海马CA3区神经元电活动及突触超微结构的影响。结果表明:大鼠在强噪声暴露期间(5min),其神经元放电出现减频反应(占53.3％),增频反应(占20％)和基本无反应(占26.7％)。而强噪声定时重复暴露(每天1h共50天)后,单位放电频率极显著地低于对照组,以及高频单位消失而低频单位增加;同时,突触超微结构(大鼠和豚鼠)也出现小泡不集中于突触前膜和线粒体空泡化增多等不利于突触功能的变化。表明强噪声对海马CA3区神经元的影响是明显的,且以抑制性作用更为显著。本文结合本室以往工作进行讨论,认为噪声影响学习功能可能有通过影响海马的活动而作用的机制。     

论扬子区中晚奥陶世和志留纪四射珊瑚的分类及一些科属的演化

扬子区中奥陶世至早、晚志留世产有丰富的四射珊瑚,尤其Ashgill期中、晚期和Llandovery世的Aero-nian—Telychian期产出珊瑚最盛。据已报道统计,该地区共有四射珊瑚124属,包括中、晚奥陶世31属,早志留世(Llandovery世)87属,晚志留世6属。其中有一些属的分类位置以及属征各家仍存在分歧。对扬子区中、晚奥陶世和志留纪四射珊瑚群已发表和笔者手中尚存资料进行系统整理之后,提出该区奥陶纪、志留纪四射珊瑚的分类意见并加以讨论,共分3个目:即扭心珊瑚目(Streptelasmatida),柱珊瑚目(Columnariida)和泡沫珊瑚目(Cystiphyllida)。其中扭心珊瑚目含有46属,分属7个科,柱珊瑚目包含37属,分属14个科,而泡沫珊瑚目包含41属,分属9个科。此外,文中提出扬子区中、晚奥陶世和早志留世四射珊瑚某些科、属的演化趋向并加以适当讨论。     

铝对原代培养大鼠海马神经细胞毒性作用的初步观察

新生一天的大鼠海马神经细胞在含10％胎牛血清和10％小牛血清的DMEM培养液,5％CO_2,37℃的环境中可以获得良好的生长。用从微摩尔浓度至毫摩尔浓度的铝处理细胞1小时,细胞死亡率明显增加,并呈剂量依赖性。但10~(-3)mol/L浓度的铝却使死亡率突然降低,与10~(-4)mol/L比较具有极显著的统计学意义。铝的神经毒作用与细胞外液中钙离子存在与否无关,不能用传统的兴奋性学说来解释。     

兔腹部迷走神经及内脏大神经传入冲动在延髓投射的电生理研究

本实验在75只家兔身上进行。观察了腹部迷走神经及内脏大神经传入冲动在延髓投射的分布、潜伏期及反应型式等特征。结果表明,腹部迷走传入冲动相对集中地投射在孤束核(NTS)及其附近区域,并呈现基本对称的双侧性投射。测定了254个延髓细胞的反应潜伏期,平均值为257.44±44.57ms((?)±SD)。内脏大神经传入投射较弥散,而且在 NTS 也有相当数量的分布。在 NTS 中存在迷走-内脏神经传入冲动的汇聚。     

DEVELOPMENT OF THE MAGNUM REGION OF THE OVIDUCT IN RELATION TO THE REPRODUCTIVE CYCLE OF THE BARBARY DOVE STREPTOPELIA ROSEOGRISEA VAR.

The magnum region of oviducts of female Barbary Doves was examined at different phases of development before egg laying, and during incubation and brooding of the young. The tubular glands in the mucosal folds of the magnum region increased in size with increase in precursor albumen granule content during the pre-egg-laying phase, and decreased during incubation and brooding. Enlargement of tubular glands was correlated with an increase in plasma progesterone level. The temporal relationships between ovarian development, ovarian hormones, oviduct development and nesting behaviour are discussed.     

电损毁海马CA_3区及连合前穹窿对大鼠血浆胰岛素水平及胰岛细胞的影响

电损毁大鼠海马CA_3区(HCA_3-EL)或连合前穹窿纤维(ACHF-EL)后,其血浆胰岛素基础水平明显升高。HCA_3-EL两周后,大鼠空腹血糖浓度增高,且糖耐量降低。但胰岛B细胞对葡萄糖刺激之分泌反应却显著增强。HCA_3-EL或ACHF-EL大鼠经静脉糖耐量试验(IVGTT)后,其胰岛A细胞内胰高血糖素样及B细胞内胰岛素样免疫阳性物质的相对含量均明显低于对照组。HCA_3-EL组大鼠胰岛中生长抑素样免疫阳性物质的相对含量及阳性细胞数目均较对照组减少,而胰岛中胰多肽样免疫阳性物质却无明显变化。上述结果表明,海马CA_3区(HCA_3)及连台前穹窿(ACHF)对胰岛素的分泌有紧张性抑制作用。     

大鼠海马移植物内神经元与CA能纤维之间突触联系的研究

将胎龄为１７ｄ的大鼠胚胎海马（移植物）移植到同种成年大鼠（宿主）腹海马,９０ｄ后,用ＴＨ免疫细胞化学方法对海马移植物内神经元与儿茶酚胺（ｃａｔｅｃｈｏｌａｍｉｎｅ ＣＡ）能纤维之间的突触联系进行上观察。免疫组织化学显示,宿主海马内有大量ＴＨ免疫反应纤维。这些纤维是直径为０．５－１μｍ的细纤维。它们的分布密度是,齿回门区和ＣＡ３区透明层内较密集,分子层次之,锥体细胞层和颗粒细胞层内较稀疏。在移植物的     

5-HYDROXYTRYPTAMINE AND NORADRENALINE IN THE HIPPOCAMPAL REGION: EFFECT OF TRANSECTION OF AFFERENT PATHWAYS ON ENDOGENOUS LEVELS, HIGH AFFINITY UPTAKE AND SOME TRANSMITTER-RELATED ENZYMES

The monoaminergic fibres enter the hippocampal formation through a dorsal and a ventral route. The dorsal route consisting of fimbria, fornix superior and cingulum, was estimated to supply about 75% of the 5-HT fibres and 40% of the noradrenaline containing (NA) fibres. The ventral route, allegedly passing through the amygdaloid area, accounts for the rest. The cingulum bundle contributes a definite part of the 5-HT fibres but very few of the NA fibres. No evidence was found for an intrinsic origin of monoaminergic fibres in the hippocampal region. Monoamine oxidase and catechol-O-methyltransferase showed no change following the lesions and are considered to be localized predominantly outside the aminergic neurones. The results on DOPA decarboxylase indicate that about 50% of the enzyme is situated outside 5-HT and NA nerves. Glutamic acid decarboxylase did not decrease even after transection of the ventral route, substantiating the earlier conclusion that this enzyme is situated in intrinsic neurones in the hippocampal region. For choline acetyltransferase and AChE the dorsal route was confirmed to be the only quantitatively important way of access. None of the enzymes studied, nor the uptake activities, were affected by cervical sympathectomy.