Chronic Morphine Treatment Impaired Hippocampal Long-Term Potentiation and Spatial Memory via Accumulation of Extracellular Adenosine Acting on Adenosine A(1) Receptors

Chronic exposure to opiates impairs hippocampal long-term potentiation (LTP) and spatial memory, but the underlying mechanisms remain to be elucidated. Given the well known effects of adenosine, an important neuromodulator, on hippocampal neuronal excitability and synaptic plasticity, we investigated the potential effect of changes in adenosine concentrations on chronic morphine treatment-induced impairment of hippocampal CA1 LTP and spatial memory. We found that chronic treatment in mice with either increasing doses (20-100 mg/kg) of morphine for 7 d or equal daily dose (20 mg/kg) of morphine for 12 d led to a significant increase of hippocampal extracellular adenosine concentrations. Importantly, we found that accumulated adenosine contributed to the inhibition of the hippocampal CA1 LTP and impairment of spatial memory retrieval measured in the Morris water maze. Adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine significantly reversed chronic morphine-induced impairment of hippocampal CA1 LTP and spatial memory. Likewise, adenosine deaminase, which converts adenosine into the inactive metabolite inosine, restored impaired hippocampal CA1 LTP. We further found that adenosine accumulation was attributable to the alteration of adenosine uptake but not adenosine metabolisms. Bidirectional nucleoside transporters (ENT2) appeared to play a key role in the reduction of adenosine uptake. Changes in PKC-alpha/beta activity were correlated with the attenuation of the ENT2 function in the short-term (2 h) but not in the long-term (7 d) period after the termination of morphine treatment. This study reveals a potential mechanism by which chronic exposure to morphine leads to impairment of both hippocampal LTP and spatial memory.

丽江拉市海保护区的鱼类区系和现存状态

2001年8、10月和1999年10月在云南丽江拉市海高原湿地自然保护区采得鱼类标本4550号. 结合文献记录, 并用参与式农村评估(PRA)与渔民讨论, 评估各鱼种的生存状态. 初步确定该保护区共有鱼类25种, 隶属5目10科21属. 其中有7个土著种, 18个引入种, 高度濒危或灭绝3种. 首次记录到秀丽高原鳅. 该地鱼类区系主要由引入种组成, 土著种正在消失。

Phylogeny and zoogeography of the cyprinid hemicultrine group (Cyprinidae : Cultrinae)

Ying-Gui Dai and Jun-Xing Yang (2003) Phylogeny and zoogeography of the cyprinid hemicultrine group (Cyprinidae: Cultrinae). Zoological Studies 42(1): 73-92. The hemicultrine group consists of middle-sized cyprinids in Asia which taxonomically belong to the subfamily Cultrinae in the Cyprinidae (Cypriniformes), but there has been no convincing generic phylogenetic hypothesis proposal so far. On the basis of a morphological study of 65 specimens soaked in formalin and 14 skeletal specimens of 8 species in 6 genera within the hemicultrine group as an ingroup, a 70-character matrix was obtained. The generic phylogenetic relationships of the hemicultrine group are hypothesized with the matrix by the method of cladistic analysis. When the species Rasborinus lineatus or Cultrichthys erythropterus is used as the sole outgroup, the matrix gives the same single most-parsimonious tree of generic phylogenetic relationships within the hemicultrine group which shows that the hemicultrine group forms a monophyletic group. However, when Rasborinus lineatus is used as the sole outgroup and Cultrichthys erythropterus and Paralaubuca barroni are included in the ingroup, the hemicultrine group is validated to represent a paraphyletic group, and the hemicultrine group and the genus Paralaubuca form a monophyletic group. The tree of generic relationships and zoogeography of the monophyletic group comprising the hemicultrine group and the genus Paralaubuca suggest the following: (1) The monophyletic group comprises 2 smaller monophyletic groups: the genera Hemiculterella + Pseudohemiculter + Hainania and the genera Hemiculter + Paralaubuca + Pseudolaubuca + Toxabramis. (2) The sister groups of the monophyletic group show both overlapping and vicariant distribution patterns; therefore the generic distribution pattern of the monophyletic group maybe have resulted from both dispersal and vicariance events. (3) The monophyletic group probably originated on the Asian mainland from the Yangtze River to the Pearl River and on Hainan Island in China. (4) The monophyletic group probably originated after the Japanese Archipelago was separated from the Asian mainland at the beginning of the Quaternary Period in the Cenozoic but before Taiwan, Hainan Island, and Indonesia were completely isolated from the Asian mainland after the ice age in the Quaternary Period. (5) Speciation of the genus Hemiculter should have been the earliest, and those of the genera Paralaubuca, Pseudolaubuca, and Hainania ought to be the latest in the process of evolution of this monophyletic group. http://www.sinica.edu.tw/zool/zoolstud/42.1/73.pdf.

Balitora nantingensis (Teleostei : Balitoridae), a new hillstream loach from Salween drainage in Yunnan, Southwestern China

A new species of hillstream loach genus Balitora Gray is discovered from Nanting River drainage, which drains to Salween, Yongde County, Yunnan, China. Balitora nantingensis can be distinguished from B. lancangjiangensis by a triangle-like blotch in nape absent vs. present; area from halfway of pelvicfin ray to anus covered by scales vs. no scales in this area; the first pectoral ray thickened vs. not; posterior end of pelvic-fin surpasses middle point from posterior end of pelvic-fin base to anal-fin origin vs. the end from posterior extremity of pelvic-fins to anus; fewer lateral line scales, 59-64 vs. 66-70; slightly longer head, SL 4.2-5.1 (4.6) times of HL vs. 5.0-5.9 (5.4); slightly larger eyes, HL 4.0-6.4 (5. 1) times of eye diameter vs. 5.5-7.5 (6.3). Balitora nantingensis can be distinguished from B. burmanica by body rounded vs. slender in dorsal view; pointed snout vs. blunt in dorsal view; a deeper body, body depth 12.5-16.9% of SL vs. 10-12%; a deeper caudal-peduncle, length of caudal-peduncle 2.0-2.8 times of its depth vs. 3.0-4.2; a shorter caudal-peduncle, 14.3-15.6% of SL vs. 16-21%; the average ratio of body width at pelvic-fin origin and distance between inner pelvic-fin base 2.0 vs. 3.4; body width 1.1-1.5 times of body depth vs. 1.5-1.6; posterior end of pelvic-fin almost one or slight more than one eye diameter from anus vs. closet to anus; outside rays of pelvic-fin extend more posteriorly than inside rays and make posterior outline of fin acclivitous and straight vs. the outside ones almost equal to the inside ones and make the fin slightly convex.

Schistura cryptofasciata, a new loach (Cypriniformes : Balitoridae) from Salween drainage in Yunnan, Southwestern China

Schistura cryptofasciata is distinguished from its congeners by following combination characters: lateral line complete; 8(1)/(2) branched dorsal-fin rays; 9+8 branched caudal-fin rays; no sexual dimorphism; 8-11 indistinct bars, wider than interspaces; caudal-peduncle length 44.1-16.5% standard length, 68.1-90.4% dorsal head length; anterior portion of body scaleless; air bladder entirely embedded in bony capsule; lateral head length 104-122% dorsal head length; lower jaw with a notch at symphysis; lower lip completely interrupted; interorbital width 1.9-2.2 times eye diameter; pelvic-fin origin ventral to dorsal-fin origin; anus 1.0-1.5 eye diameters in front of anal-fin origin; the widest part of black basal caudal bar is the midlateral, and then the upper and lower ends.

A new species of sisorid catfish genus Glyptothorax (Teleostei: Sisoridae) from Salween drainage of Yunnan, China

A new species of the genus Glyptothorax, Glyptothorax obliquimaculatus sp. nov. is described from the Xiaohei River, a tributary of the Nanting River, Salween drainage, in southwestern Yunnan province, China. This new species can be distinguished from its congeners by the following combination of characteristics: unculiferous ridges of the thoracic adhesive apparatus extending anteriorly onto the gular region; body with irregular dark blotches scattered along lateral surface (blotches mostly oblique); skin smooth on head and body; dorsal spine smooth without serrations on its posterior margin; lips smooth; posterior margin of pectoral spine with 7-8 serrations; dorsal-fin base 11.0-13.2% SL; pectoral-fin length 15.6-19.6% SL; depth of caudal peduncle 8.6-9.8% SL; head width 19.1-24.0% SL; nasal barbel length 23.3-33.3% HL.

反渗透膜进水预处理及水质硬度过大的对策

超纯水系统中的反渗透膜无法长时间在原水水质硬度过大的条件下正常运转,本文就原水水质硬度大对反渗透膜的不良影响,及软水剂、防垢剂除盐法和阳树脂交换除盐法这两种软化水方法的实际效果进行了探讨和比较.经过长期实践,采用膜前树脂交换除盐法为主,各类添加剂为辅的前处理方法成功解决了这一问题.

婴猴麻疹38例临床分析

麻疹病毒是副粘病毒科麻疹病毒属成员之一,主要通过呼吸道传播,其传染性强,人群发病率很高,主要常发于婴幼儿及儿童[1].国外有报道人源麻疹病毒和狗的犬温热病毒可引起捕获猕猴麻疹病毒感染的暴发[2-4],并表现为与人相似的临床症状和病理表现[5-6].目前,国内还未有猕猴麻疹暴发的病例报道.本中心2008年1月至3月共有38例8月龄~15月龄的腹泻猕猴诊断为麻疹,经过及时确诊,有效治疗,临床效果很好的.分析如下.

A homogenous nature of native Chinese duck matrilineal pool

Background: China, with around 30 unique breeds, has a diverse duck genetic pool. Currently, there is no systematic report which investigates the genetic diversity, phylogenetic relationship, and matrilineal genetic structure of these domestic breeds and

信息素受体V1R基因家族基因数目在哺乳动物中存在巨大差异

信息素是由动物分泌的化学物质,用于影响同种动物的行为,其感觉器官叫做犁鼻器,是一个位于鼻中隔底部的软骨结构。信息素受体由V1R和V2R两个基因超家族编码。美国密歇根大学张建之研究小组与中科院昆明动物所张亚平等合作,通过对目前可利用的哺乳动物基因组工作草图的分析,发现V1R基因家族的基因数目在哺乳动物中存在着巨大的差异,是目前所知的基因数目差异倍数最大的哺乳动物基因家族,其中,小鼠、老鼠、狗、牛和负鼠的V1R基因数目分别为187、102、8、32和49。研究人员认为,V1R基因家族这种惊人的差异主要是由基因的快速新生与消亡过程造成的,即:在食肉类和偶蹄类动物中多次发生丢失祖先V1R基因的情况,而在啮齿类动物中却通过基因重复的形式产生了许多新基因。V1R基因家族在不同物种中的巨大差异可能反映了不同物种对信息素的感受能力的不同。此外,该研究结果还表明了V1R基因家族的大小和犁鼻器形态上的复杂程度紧密相关,提示着具有形态复杂的犁鼻器的物种可能也具有复杂的信息素传递系统。该研究结果不仅证明了哺乳动物的V1R基因家族惊人的多样性和快速的进化历程,还提示当利用模式生物小鼠所获得的信息素知识推广、应用到其它的哺乳动物时,一定...

不同地域卵黄萤荧光素酶基因的克隆与序列分析

为了比较不同地域萤火虫荧光素酶基因的进化关系,通过GenBank中已知的荧光素酶基因保守区段设计引物,利用5'-RACE(rapid-amplification of cDNA ends)和3'-RACE技术克隆了来自云南省文山州和西双版纳州的同种卵黄萤荧光素酶基因cDNA和全基因序列.来自不同地域的2种卵黄萤荧光素酶在基因序列上存在3个不同碱基位点,但是它们编码的荧光素酶只存在1个不同的氨基酸.卵黄萤荧光素酶基因全长(从起始密码子到终止密码子)1998 bp,包含7个外显子,6个内含子,其cDNA序列共1976 bp,包含102 bp 5'UTR(untranslated region)、1635 bp的荧光素酶基因开放阅读框和239 bp的3'UTR序列.卵黄萤荧光素酶基因的开放阅读框编码1个544个氨基酸的蛋白质,比同属的其它几种荧光素酶少4个氨基酸.来自2个不同地域的卵黄萤荧光素酶在进化上是比较保守的,它们与北美萤火虫Photinus pyralis荧光素酶在碱基序列上分别有62.9%和63%相似性.

Cloning,Expression and Sequence Analysis of A Luciferase Gene from the Chinese Firefly Pyrocoelia pygidialis

从一种来自中国日行性萤火虫(云南窗萤)发光器官mRNA中克隆、测序并表达了有功能的荧光素酶.云南窗萤荧光素酶的cDNA序列有1647个碱基,编码548个氨基酸残基.从推测得到的氨基酸序列的比对分析得出:云南窗萤的荧光素酶与来自Lampyris noctiluca,L.turkestanicus和Nyctophila cf.caucasica三种萤火虫的荧光素酶有97.8%的序列一致性.从推测得出的氨基酸序列进行系统发育分析,其结果表明:云南窗萤和Lampyris+Nyctophila聚在一起,与同属的发光强夜行性的萤火虫不形成的单系.云南窗萤荧光素酶在大肠杆菌中表达的条带大约70kDa,并且在有荧光素存在时发出黄绿色荧光.对荧光素酶的结构模拟和分析表明,云南窗萤荧光素酶基因的氨基端和羧基端结构域之间的裂沟处存在这5个多肽环,这正是从其他荧光素酶推测得到的催化荧光反应时的底物结合位点.云南窗萤和窗萤属的其他3种萤火虫的荧光素酶卡目比,有13个不同氨基酸位点,位于模拟分子结构的表面.对于这些多肽环、不刚氨基酸残基和晶体结构的进一步研究有利于解释日行和夜行性萤火虫荧光素酶的差异.

Effect of Pyrethrins and Rosemary on the ATPase Activities of Rat Cerebral Synaptosome

除虫菊酯越来越广泛地被应用于农业和家庭昆虫防治,主要通过作用于膜结合蛋白而对动物起神经毒性.迷迭香因其抗氧化功能而被应用于很多商业化的除虫菊酯产品中.本实验以大鼠大脑突触体ATP酶为研究对象,对除虫菊酯和迷迭香的药理学进行了研究.用Percoll梯度离心法分离突触体,通过检测无机磷的量来测定总ATP酶和Mg2+-ATP酶活性.结果表明,除虫菊酯在浓度为10 μmol/L时总ATP酶和Mg2+-ATP酶分别降低到对照的80.3%和46.9%.迷迭香在浓度为0.3～30 μmol/L时几乎不影响ATP酶活性,当浓度上升到3 000 μmol/L时,总ATP酶活性降低到66.8%,而Mg2+-ATP酶活性降低到54.5%. 10 μmol/L 除虫菊酯和30 μmol/L迷迭香混合物引起总ATP酶和Mg2+-ATP酶分别降低到72.9%和33.4%.结论: 1) 除虫菊酯能抑制大鼠大脑ATP酶活性; 2) 迷迭香只在高浓度下才对ATP酶有抑制作用; 3) 迷迭香能增强除虫菊酯对ATP酶的抑制作用.图3参19