A strong influence of serotonin axons on beta-adrenergic receptors in rat brain

The role of serotonin axons in modulating the norepinephrine neurotransmission system in rat brain was investigated. Selective lesions of the forebrain serotonergic system were made by injecting 5,7-dihydroxytryptamine into the midbrain raphe nuclei. Four to six weeks after the lesion, the uptake of 3H-labeled serotonin in the frontal cortex and the hippocampus was reduced by more than 90 percent, while neither the uptake of 3H-labeled norepinephrine nor the content of norepinephrine was affected in either tissue. The number of beta-adrenergic receptors, as measured by radioligand binding with 3H-labeled dihydroalprenolol, was increased in the frontal cortex and hippocampus of rats with lesions. Similarly, specific lesions of central serotonin axons produced by systemically administered p-chloramphetamine resulted in an increase in the binding of 3H-labeled dihydroalprenolol to beta-adrenergic receptors and in the production of adenosine 3',5'-monophosphate in response to isoproterenol. These results indicate that serotonin axons may regulate beta-adrenergic receptor number and function in brain.     

Neurons generated in the adult brain are recruited into functional circuits

Adult canaries, Serinus canarius, received injections of 3H-labeled thymidine, a marker of DNA synthesis. Thirty days after the last injection, intracellular potentials were recorded from neurons in the nucleus hyperstriatum ventralis pars caudalis, a vocal control nucleus in the telencephalon; these same cells were then injected with horseradish peroxidase. Of the 74 neurons labeled with horseradish peroxidase that were recovered, the nuclei of seven were radioactively labeled. Four of these seven neurons had responded to auditory stimuli. These double-labeled neurons were apparently generated during or after the 3H-labeled thymidine treatment (during adulthood) and subsequently incorporated into functional neural circuits.     

Direct evidence that endogenous GM1 ganglioside can mediate thymocyte proliferation

The B subunit of cholera toxin, which is multivalent and binds exclusively to a specific ganglioside, GM1, was mitogenic for rat thymocytes. When exposed to the B subunit, the cells proliferated, as measured by 3H-labeled thymidine incorporation. Mitogenesis depended on the direct interaction of the B subunit with GM1 on the surface of the cells. This demonstrates that endogenous plasma membrane gangliosides can mediate proliferation in lymphocytes.     

水生无脊椎动物血淋巴细胞分类及免疫研究进展

水生无脊椎动物的血淋巴细胞是机体免疫防御屏障的重要组成部分,但对不同水生无脊椎动物的血淋巴细胞分类和功能的研究整体上比对脊椎动物的研究落后。本研究中系统地归纳和综述了贝类、甲壳类、棘皮动物等水生无脊椎动物血淋巴细胞的分类及其免疫功能的研究进展,贝类血淋巴细胞的分类主要以染色后细胞质中颗粒物质的有无作为指标,一般分为颗粒细胞(granulocyte)和透明细胞(hyalinocyte),其防御机制主要通过包囊作用、伤口修复、吞噬作用等方面体现;甲壳动物血淋巴细胞的分类主要依据血淋巴细胞的形态特征和胞质中颗粒物质的有无、大小和密度等特征,一般将其分为无颗粒细胞(hyaline cell)、小颗粒细胞(semi-granular cell)和大颗粒细胞(granular cell),透明细胞和小颗粒细胞共同介导吞噬作用,小颗粒细胞还介导包囊作用,大颗粒细胞主要介导细胞毒作用;棘皮动物的细胞免疫主要由体腔细胞即变形吞噬细胞或颗粒细胞完成。建议未来应使用多种方法和技术以及结合血淋巴细胞表面受体对水生无脊椎动物血淋巴细胞进行分类和功能研究。     

Long-term facilitation in Aplysia involves increase in transmitter release

In a variety of vertebrates and invertebrates, long-lasting enhancement of synaptic transmission contributes to the storage of memory lasting one or more days. However, it has not been demonstrated directly whether this increase in synaptic transmission is caused by an enhancement of transmitter release or an increase in the sensitivity of the postsynaptic receptors. These possibilities can be distinguished by a quantal analysis in which the size of the miniature excitatory postsynaptic potential released spontaneously from the presynaptic terminal is used as a reference. By means of microcultures, in which single sensory and motor neurons of Aplysia were plated together, miniature excitatory postsynaptic potentials attributable to the spontaneous release of single transmitter quanta from individual presynaptic neurons were recorded and used to analyze long-term facilitation induced by repeated applications of 5-hydroxytryptamine. The results indicate that the facilitation is caused by an increase in the number of transmitter quanta released by the presynaptic neuron.     

新西兰无脊椎动物多样性及面临的威胁

对当前新西兰无脊椎动物生物多样性状况,以及新西兰无脊椎动物生物多样性所面临的威胁等进行了综述．在新西兰共有31种无脊椎动物被列入最受威胁的物种名录,其中昆虫18种、螨类1种、环节动物1种、软体动物11种．人类活动、栖息地破坏和外来物种的入侵是新西兰无脊椎动物多样性面临的主要威胁．     

分解袋法在湿地枯落物分解研究中存在的问题与对策

分解袋法是研究湿地植物枯落物分解应用最广泛的方法,但在研究湿地挺水植物枯落物分解时存在一些问题。首先,容易忽视挺水植物立枯分解阶段;其次,在研究不同类型无脊椎动物和微生物的分解功能时,不同网孔的分解袋都一定程度地阻碍了无脊椎动物,而且不同网袋中微生物的数量和活性等生态性质不一定相同,因而分解袋法不利于区分不同功能群的无脊椎动物和微生物;另外,分解袋法实验周期长,工作量大,枯落物残留量测量不准确。今后要加强湿地挺水植物枯落物分解的机理研究,在此基础上改进实验方法。     

海洋无脊椎动物多不饱和脂肪酸合成代谢机理研究进展

近年来,人们对水产品质量安全、优质的动物蛋白以及脂肪来源的关注度越来越高。海洋无脊椎动物不仅是优质食物蛋白的重要来源,也是人体获取多不饱和脂肪酸（polyunsaturated fatty acids,PUFA）的主要食物来源。研究表明,几乎所有的PUFA都来自于水生生态系统中的初级生产者,海洋中主要初级生产者微藻生产出PUFA进入食物链后,较高营养级生物可通过生物转化或修饰产生新的PUFA。关于初级生产者和脊椎动物中PUFA合成代谢的研究较多,但位于两者之间无脊椎动物PUFA的生物合成代谢途径却知之甚少。因此,本文对五类海洋无脊椎动物（多孔动物、刺胞动物、软体动物、甲壳动物和棘皮动物）PUFA的合成代谢途径以及参与其过程中重要酶和关键基因的研究进展进行了总结,以期为更深入地理解海洋无脊椎动物PUFA的合成代谢与调控体系提供有价值的参考资料。     

无脊椎动物促性腺激素释放激素研究进展

促性腺激素释放激素（gonadotropin-releasing hormone,_GnRH）是下丘脑-垂体-性腺（hypothalamic-pituitary-go-nad,_HPG）轴的关键信息分子,在脊椎动物的性腺发育、性成熟和繁殖功能的维持中起着重要作用。用免疫组织化学、酶联免疫吸附测定以及高效液相色谱等方法在多种无脊椎动物中也检测到了其存在,主要分布于中枢神经以及生殖系统。可见,GnRH在无脊椎动物中具有普遍存在性。目前已至少发现28种类型的GnRH,15种来自脊椎动物,13种来自无脊椎动物。目前,无脊椎动物中除被囊动物外,仅有真蛸、海兔和商乌贼已经获得了GnRH的mRNA序列,其肽链分子结构与脊椎动物的类似。GnRH在无脊椎动物中具有广阔的研究空间,将为无脊椎动物的生殖调控的研究提供参考。     

单克隆抗体在水产无脊椎动物血淋巴细胞研究中的应用

近年来,单克隆抗体在水产无脊椎动物血淋巴细胞研究中的应用越来越广泛,迄今报道的研究种类主要是对虾和贝类,另外还包括一些其他水产无脊椎动物,如海参等。主要应用于血淋巴细胞的识别和鉴定,并对其个体的发生和分化方面也进行了初步的研究。对单克隆抗体在水产无脊椎动物血淋巴细胞的分类、分布、发生和功能研究等方面的应用进行了综述。     

Detection of two viral genomes in single cells by double-label hybridization in situ and color microradioautography

Double labeling and color microradioautography were used in a new method of hybridization in situ to identify different genes in individual cells. The method is based on the unequal penetration of 3H and 35S into two layers of nuclear track emulsion separated by a thin barrier film. Hybridization of a 35S-labeled probe specific for one kind of gene results in silver grains over cells in both layers of emulsion; a 3H-labeled probe for a second gene provides grains only in the first layer of emulsion. Silver grains are converted to magenta-colored grains in the first layer and to cyan-colored grains in the second to facilitate enumeration of grains in each layer. This technique should be widely applicable in analyses of differential gene expression in single cells or in discrete populations of cells.     

Endotoxin-stimulated opioid peptide secretion: two secretory pools and feedback control in vivo

Small doses of endotoxin evoked a dramatic biphasic response of opioid peptide secretion into blood in sheep. The first phase began within minutes and coincided with a brief hypertensive response to endotoxin well before the appearance of fever or hypotension. The ratio of beta-endorphin to beta-lipotropin fell abruptly at the onset of the second phase of release, suggesting early depletion of a pool rich in beta-endorphin and subsequent emergence of a pool rich in unprocessed precursor. The concentration of cerebrospinal fluid opioids increased tenfold during the second phase. Naloxone administration augmented endotoxin-induced opioid secretion in both early and late phases, suggesting a short-loop feedback regulation of stress-induced endorphin secretion.     

黄顶菊(Flaveria bidentis)凋落物对土壤无脊椎动物群落的影响

以黄顶菊(Flaveria bidentis)入侵的林地、荒地和沟渠作为调查样地,探讨黄顶菊凋落物对土壤无脊椎动物群落的影响。利用环刀进行取样,3种生境共捕获土壤无脊椎动物54315头,隶属2门10纲17目。3种生境的优势类群皆为蜱螨目和弹尾目,其余类群的相对多度较小。黄顶菊凋落物能够为土壤无脊椎动物提供栖息地与食物来源,进而影响其群落结构及多样性,该影响与黄顶菊自身群体的生长状况有关,在长势较弱的林地生境影响较小,而在长势较强的荒地和沟渠生境影响较大。综上所述,黄顶菊入侵3种生境后,植株及其凋落物能为优势类群提供更好的栖息地和隐蔽所,并通过改变表层腐殖土的主要养分含量,引起土壤无脊椎动物多样性的升高,且土壤无脊椎动物在凋落物层中多样性呈自上而下的升高趋势。     

淮河流域贾鲁河栖息地完整性评价分析

运用多指标综合评价体系,评价了贾鲁河9个河流断面的栖息地质量状况,分析了栖息地综合指数(HI)与水质理化指标、底栖动物的相关关系,探讨了栖息地质量状况影响底栖动物分布的主要途径。结果表明,贾鲁河9个河段中,有超过50%的河段处于不健康状态;栖息地质量与水质无显著相关性,但与底栖动物生物量、B-IBI指数、Goodnight-Whitley指数、Shannon-Wiener多样性指数均显著相关(P<0.05);栖息地主要通过河道内生境变化与河滨带土地利用变化影响贾鲁河底栖动物的分布特征,其中底质类型和城镇土地利用强度是影响底栖动物分布的两大因素。     

Anatomically distinct opiate receptor fields mediate reward and physical dependence

Rats never before exposed to opioids rapidly learned to press a lever for microinjections of morphine into the ventral tegmental area. Challenge by a narcotic antagonist produced no signs of physical dependence. Dependence was not seen after long-term morphine infusions into the ventral tegmentum but was seen after similar infusions into the periventricular gray region. Thus a major rewarding property of morphine is independent of the drug's ability to produce physical dependence. These data challenge models of drug addiction that propose physical dependence as necessary for the rewarding effects of opioids.     

转基因抗虫棉对土壤无脊椎动物群落的影响

选择连续种植传统非转基因棉、5年连续种植转基因抗虫棉和10年连续种植转基因抗虫棉的棉田为研究对象,调查了土壤0～20 cm的小型无脊椎动物的群落组成和多样性变化.结果表明,与种植传统非转基因棉相比,种植转基因抗虫棉对土壤小型无脊椎动物的种类和数量等没有显著性差异,但减少了双翅目的优势种群.种植5年转基因抗虫棉会降低土壤无脊椎动物的Simpson指数、Shannon-Wiener多样性指数和Pielou均匀度.     

Effects of Acid rain on freshwater ecosystems

Acid-vulnerable areas are more numerous and widespread than believed 7 years ago. Lakes and streams in acid-vulnerable areas of northeastern North America have suffered substantial declines in acid-neutralizing capacity, the worst cases resulting in biological damage. Many invertebrates are very sensitive to acidification, with some disappearing at pH values as high as 6.0. However, the recent rate of acidification of lakes is slower than once predicted, in part the result of decreases in sulfur oxide emissions. A discussion of some of the processes that have contributed to the acidification of lakes as well as those that have protected acid-sensitive freshwaters is presented. The author is in the Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba R3T 2N6, Canada.     

土壤微塑料污染的生态效应

土壤环境中微塑料积累量大且不易降解，因此微塑料长期残留对土壤生态系统的影响已引起广泛关注。通过收集近年来有关土壤微塑料污染及其效应相关的文献，全面系统介绍了土壤微塑料积累后，土壤物理环境的变化、土壤动物摄入及其肠道微生物的响应、土壤微生物和土壤酶活性响应、以及植物对微塑料的吸收及其效应等方面的最新研究进展。现有研究结果表明:微塑料污染对土壤容重、团聚体组成和持水性等土壤物理性质有明显改变，而这些改变是影响土壤酶活性、微生物群落组成、甚至植物生长的关键因素。也有一些研究关注土壤无脊椎动物(如蚯蚓Lumbricus terrestris、跳虫Folsomia candida等)对微塑料在土壤中迁移的影响。同时，微塑料也会被这些土壤动物所摄食，并导致土壤动物体内肠道微生物群落组成的变化以及对其生长产生影响。此外，微塑料在陆地生态系统食物链中的积累及其效应也受到关注，比如，被蚯蚓摄食的微塑料可通过鸡Gallus gallus domesticus摄食蚯蚓进入鸡体内积累。在系统介绍土壤微塑料污染生态效应的研究进展基础上，结合微塑料组成与性质的复杂性以及当前研究的不足，提出4个未来研究方向:①建立土壤微塑料污染毒理学诊断的标准化方法体系；②研究土壤微塑料与微生物、植物和土壤动物之间的作用机理；③揭示微塑料与物质转化之间的关键微生物学机制；④开展不同土壤生态系统中的“塑料圈”研究。这些研究成果可为评估土壤微塑料污染的生态效应提供科学支撑。参80     

Calcium as a coagonist of inositol 1,4,5-trisphosphate-induced calcium release

Inositol 1,4,5-trisphosphate (IP3)-induced calcium release from intracellular stores is a regulator of cytosolic-free calcium levels. The subsecond kinetics and regulation of IP3-induced calcium-45 release from synaptosome-derived microsomal vesicles were resolved by rapid superfusion. Extravesicular calcium acted as a coagonist, potentiating the transient IP3-induced release of calcium-45. Thus, rapid elevation of cytosolic calcium levels may trigger IP3-induced calcium release in vivo. Extravesicular calcium also produced a more slowly developing, reversible inhibition of IP3-induced calcium-45 release. Sequential positive and negative feedback regulation by calcium of IP3-induced calcium release may contribute to transients and oscillations of cytosolic-free calcium in vivo.     

江苏省农业生态系统外来入侵动植物初步研究

通过调查江苏省农业生态系统外来入侵动植物现状,共查明陆生植物86种,水生植物6种,陆生无脊椎动物20种,水生无脊椎动物1种,两栖类1种,哺乳类2种。并从种类构成及其与国家种类构成的对比、原产地、省内分布特征以及危害等方面,分析了江苏省农业生态系统外来入侵动植物的现状,在此基础上提出了农业生态系统外来入侵动植物的管理对策。