两栖类峡核的顶盖外投射

用辣根过氧化物酶法研究了中华大蟾蜍峡核的顶盖外投射。结果指出：（１）中脑脚盖前背核、中脑深核和表层峡网核投向双侧峡核,对侧投射经过Ｖｅｌｉ交叉;（２）这些脚盖核投向整个峡核,其间没有区域对应关系,讨论了这些投射的可能功能意义。     

家鸽峡核顶盖通路的神经传递

采用微量离子电泳的方法研究了家鸽峡核顶盖的神经传递。电刺激峡核小细胞部（Ｉｐｃ）主要诱发顶盖细胞的抑制性反应（Ｉ－型）,也有少量兴奋－抑制型反应（ＥＩ－型）,兴奋性反应以乙酰胆碱为递质,抑制性反应则以ＧＡＢＡ为递质。据推测,Ｉｐｃ可能通过直接的神经投射调制顶盖细胞的活动。     

蛤蚧豆状核的结构及其与顶盖前端的纤维联系

运用Nissl法和辣根过氧化物酶(horseradish peroxidase,HRP)追踪标记技术,研究蛤蚧(Gekko gecko)豆状核的结构及其与顶盖前端的纤维联系。Nissl染色显示,蛤蚧豆状核细胞大小没有明显差别,由背内侧细胞密集部和腹外侧细胞稀疏部组成。将HRP注射于顶盖前端,结果豆状核背内侧部和腹外侧部分别接受同侧顶盖前端脑室内、外侧纤维的传入,核内标记有浓密的神经丛和大量纤维末梢,并在该核腹外侧部及其邻近区域发现少量大胞体标记细胞。推测豆状核腹外侧部的大胞体细胞及其邻近区域的大胞体细胞可能具有相同的功能,且该核可能形成离顶盖通路和副视系统相联系的交通要道。     

鸟类峡核传入通路及其细胞起源

采用辣根过氧化物酶（ＨＲＰ）和荧光染料固兰（ＦＢ）逆向追踪技术研究了家鸽峡核大细胞部（Ｉｍｃ）的顶盖传入投射及其细胞起源。结果表明,同侧顶盖ＩＩｉ和ＩＩＩ层细胞投射到Ｉｍｃ,或其轴突在Ｉｍｃ内有分枝末梢。结合以前的研究得出结论,鸟类顶盖与同侧Ｉｍｃ之间有交互神经联系,构成了一个视觉反馈回路     

下丘脑背内侧核在缰核兴奋诱发的心血管反应及腓深神经抑制中的作用

目的 :阐明下丘脑背内侧核 (DMH)在缰核 (Hb)兴奋诱发的心血管反应中的作用及DMH在腓深神经 (DPN)传入冲动调节Hb兴奋诱发的心血管活动中的作用及机制。方法 :脲酯和氯醛糖混合静脉麻醉的家兔 ,电刺激Hb、腓深神经 ,记录股动脉血压及心外膜电图 ,DMH内微量注射受体拮抗剂。结果 :同侧DMH微量注射谷氨酸受体阻断剂Kynurenicacid ,部分取消了电刺激Hb兴奋诱发的升压反应及缺血性心电变化反应。同侧DMH微量注射纳洛酮对腓深神经传入冲动抑制Hb兴奋诱发的上述反应有削弱作用。结论 :DMH及其中的谷氨酸受体参与电刺激缰核兴奋诱发的心血管反应 ,DMH及其中的阿片受体参与了DPN传入冲动对上述心血管反应的抑制作用     

锡嘴雀和家鸽中脑发声与听觉核团传入联系的比较研究

作者采用HRP神经轴突逆行标记的方法对鸣禽锡嘴雀(Coccothraustes coccothraustes)、非鸣禽家鸽(Columba livia domesticus)丘间核内发声与听觉核团的传入联系进行了比较研究。结果表明:丘间核内侧部的背内侧亚核接受来自前脑发声运动核团的传入;外侧部的背外侧亚核接受来自脑干听觉中继核的传人。鸣禽与非鸣禽的两亚核接受下行纤维投射的部位既有共同之处,亦存在着差异。     

CELLULAR COMMUNICATION AND COUPLING WITHIN THE SUPRACHIASMATIC NUCLEUS

In mammals, the part of the nervous system responsible for most circadian behavior can be localized to a pair of structures in the hypothalamus known as the suprachiasmatic nucleus (SCN). Importantly, when SCN neurons are removed from the organism and maintained in a brain slice preparation, they continue to generate 24h rhythms in electrical activity, secretion, and gene expression. Previous studies suggest that the basic mechanism responsible for the generation of these rhythms is intrinsic to individual cells in the SCN. If we assume that individual cells in the SCN are competent circadian oscillators, it is obviously important to understand how these cells communicate and remain synchronized with each other. Cell-to-cell communication is clearly necessary for conveying inputs to and outputs from the SCN and may be involved in ensuring the high precision of the observed rhythm. In addition, there is a growing body of evidence that a number of systems-level phenomena could be dependent on the cellular communication between circadian pacemaker neurons. It is not yet known how this cellular synchronization occurs, but it is likely that more than one of the already proposed mechanisms is utilized. The purpose of this review is to summarize briefly the possible mechanisms by which the oscillatory cells in the SCN communicate with each other. (Chronobiology International, 18(4)579–600, 2001)     

SMALL GRANULES IN THE AMPHIBIAN OOCYTE NUCLEUS AND THEIR RELATIONSHIP TO RNA

Small particles (100 to 300 A in diameter) are seen in sections of nucleoli, the loops of the amphibian lampbrush chromosomes, and the Balbiani-ring regions of dipteran salivary-gland chromosomes. All of these structures contain cytochemically demonstrable RNA. Furthermore, the annuli seen on the nuclear envelope are composed of small particles which are similar to or identical with those commonly associated with the endoplasmic reticulum. It seems likely that ribonucleoproteins are organized as small particulates in the nucleus as well as in the cytoplasm.     

重庆市两栖动物资源及现状

依据近３０年的野外调查采集结果,重庆市现有两栖动物２目８科１８属３３种。区系组成以华中区物种占绝对优势,为５１．５２％。地理分布上处于盆中平原丘陵省的物种仅１２种,盆地东北缘大巴山省有２４种,盆地东南缘山地省有２８种。对重庆的两栖动物多样性和资源类型进行了分析,概括了资源利用现状。     

THE DEVELOPMENT OF GOLGI COMPLEXES AND THEIR DEPENDENCE UPON THE NUCLEUS IN AMEBAE

The production of Golgi complexes was investigated in Amoeba proteus by introducing a nucleus into cells that had been enucleated for 5 days. Golgi complexes were not detected in 5 day enucleates, nor were they observed in amebae fixed 15 min after renucleation. Samples taken at longer intervals after the introduction of a nucleus exhibited an increase in the size and abundance of Golgi complexes. Small curved smooth cisternae, some of which were aligned in parallel to form small Golgi complexes, were observed 30 min after the operation. Aggregations of small Golgi complexes increased in number in amebae fixed 1 to 6 hr after renucleation. Golgi complexes of normal size were present 6 hr after the operation and became more abundant in samples fixed 12 hr, and 1, 2, and 3 days after renucleation. The possible participation of the granular endoplasmic reticulum in the development of Golgi complexes was suggested by two observations. First, the Golgi complexes in renucleates contained a dense material similar to the content of the endoplasmic reticulum in enucleates and early renucleates. Second, examples of continuity between the endoplasmic reticulum and Golgi cisternae were present in renucleates. The possibility that Golgi complexes can be produced in the absence of preexisting Golgi complexes is discussed.     

中国化石两栖类和有鳞类研究进展:过去15年回顾

过去15年中,我国的化石两柄类和有鳞类研究取得了加速进展。共报道了16种两栖类和22种有鳞类,其中15种两栖类和11种有鳞类为新种,包括我国最古老的四足动物宁夏晚泥盆世的潘氏中国螈,湖北中三叠世的大型全椎两栖类宽头远安鲵,东北晚侏罗世/早白垩世的多种滑体两栖类(如无尾类三燕丽蟾和北票中蟾,有尾类奇异热河螈和东方塘螈),华北占近纪的蜥蜴类(如淅川短齿蜥和垣曲响蜥),以及内蒙古晚白垩世的多种蜥蜴类等。部分旧属种被修订,多与热河生物群的种类有关,如细小矢部龙过去依据幼年个体被认为是一种小型细弱的蜥蜴,新材料显示它实为大型强壮的种类。一批新的两栖类和有鳞类重要化石点被发现,如辽宁北票市四合屯、陆家屯和葫芦岛市水口子,河北丰宁县炮仗沟以及内蒙古宁城县道虎沟和乌拉特后旗巴彦满达呼。我国晚侏罗世/早白垩世两栖类和有鳞类对研究滑体两栖类和有鳞类相关类群的起源和早期演化提供了重要信息,但系统发育研究工作尚处于初级阶段。     

RELATION BETWEEN METAMORPHOSIS AND OTHER DEVELOPMENTAL PHENOMENA IN AMPHIBIANS

1. The difference in time existing between the first shedding of the skin and the reduction of the gills to mere stubs without fringes is constant and unchangeable, which indicates that the fundamental cause for both is a common one. 2. This common cause is the action of iodine, and consequently both phenomena constitute, or at least are part of, the metamorphosis of the salamanders. 3. The development of the adult skin coloration and of the legs may take place either before or after metamorphosis. Iodine cannot enforce either of these phenomena. 4. The same is true of the development of the sex organs. 5. Development of the tongue and palatal teeth can be checked even in animals in which metamorphosis takes place. 6. Consequently development of the skin coloration, as well as development of the legs, sex organs, tongue, and palatal teeth are all caused by substances not identical with the substances causing metamorphosis and, since they are also all independent of each other in their development, it is probable that special chemical mechanisms exist for the development of each one of these six groups of organs. 7. This assumption is also supported by the fact that the order of development in several of these organ pairs can be changed by a difference in temperature, which would indicate that the development of each of these groups of organs is caused by chemical reactions with different temperature coefficients. 8. That the germ cells can develop in amphibians either before or after metamorphosis does not mean that the germ plasma is opposed as a unit to the somatic plasma, since other organs which are believed to be part of the somatic plasma behave in this respect like the germ cells. 9. The noteworthy feature of the amphibian metamorphosis is that instead of being controlled and kept in harmony by the organic individual the development of at least six groups of organs is controlled separately by the action of probably six different chemical mechanisms, each of which can be stopped or enforced independently either by directly supplying the substances required or by causing an increased formation within the body by suitable temperatures.     

Rubisco和RCA在青菜叶绿体中的分布及病毒侵染对其细胞定位的影响

运用免疫金标电镜术观察了青菜叶细胞中光合作用关键酶Rubisco和Rubisco活化酶(RCA)的细胞化学定位,结果显示Rubisco和RCA免疫金颗粒主要分布于薄壁组织叶绿体的间质中,在基粒片层上很少,表皮的气孔保卫细胞和维管束薄壁细胞叶绿体内也有分布,在细胞质及线粒体等细胞器中无特异性分布。同时比较观察了感染芜菁花叶病毒(TuMV)的青菜叶绿体Rubisco和RCA免疫金标记结果,发现病组织中结构尚完整的叶绿体Rubisco和RCA标记率略有下降,而结构严重破坏的叶绿体中两种酶标记率分别仅为正常叶绿体的58.44%和64.67%,表明病毒侵染可导致Rubisco和RCA含量下降,影响寄主植物的光合作用。     

山东省两栖爬行动物多样性

山东省有两栖爬行动物３７ 种, 有３ 种为省新记录。其中两栖类１０ 种, 分别隶属２ 目５ 科; 爬行类２７种, 分别隶属２ 目９ 科。     

THE EVOLUTION OF PARASITISM IN RED ALGAE: CELLULAR INTERACTIONS OF ADELPHOPARASITES AND THEIR HOSTS1

In the initial stages of cell–cell interactions (spore germination and host penetration), the adelphoparasites Gardneriella tuberifera Kyl. and Gracilariophila oryzoides Setch. & Wilson form infection rhizoids that fuse directly with underlying host epidermal or cortical cells. In so doing, parasite nuclei and other organelles enter the cytoplasm of the host. The resulting heterokaryon may fuse with adjacent host cells either directly, via secondary pit connections, or by the dissolution or dislodgment of pit plugs from existing pit connections. The cell fusion events result in a heterokaryotic syncytium in which parasite nuclei replicate. In Gardneriella, formation of the syncytium induces surrounding host tissues to divide to form a photosynthetic callus. The internalized syncytium forms conjunctor and rhizoidal cells that fuse with host callus, eventually transforming the host callus into cells containing parasite nuclei. Gracilariophila does not induce surrounding host tissue to divide. Rather, division of the initial heterokaryotic tissue gives rise to the colorless mantle that protrudes from the host and forms reproductive structures. The heterokaryotic tissue also fuses with underlying host cells, thereby spreading parasite nuclei throughout adjacent host cells. In both these adelphoparasites, transformation of host cells by parasite nuclear invasion results in plastid dedifferentiation, an increase in mitochondria, autolysis of organelles, and accumulation of large amounts of floridean starch. The development and physiology of these parasites is similar to normal post-fertilization processes in the hosts that give rise to carposporophytes and suggests that these adelphoparasites may have originated from perturbations of developmental pathways involved in their host's post-fertilization development.