Transplanted hypothalamic neurons restore leptin signaling and ameliorate obesity in db/db mice

Evolutionarily old and conserved homeostatic systems in the brain, including the hypothalamus, are organized into nuclear structures of heterogeneous and diverse neuron populations. To investigate whether such circuits can be functionally reconstituted by synaptic integration of similarly diverse populations of neurons, we generated physically chimeric hypothalami by microtransplanting small numbers of embryonic enhanced green fluorescent protein-expressing, leptin-responsive hypothalamic cells into hypothalami of postnatal leptin receptor-deficient (db/db) mice that develop morbid obesity. Donor neurons differentiated and integrated as four distinct hypothalamic neuron subtypes, formed functional excitatory and inhibitory synapses, partially restored leptin responsiveness, and ameliorated hyperglycemia and obesity in db/db mice. These experiments serve as a proof of concept that transplanted neurons can functionally reconstitute complex neuronal circuitry in the mammalian brain.     

Migration and differentiation of cerebral cortical neurons after transplantation into the brains of ferrets

Cells from the cerebral proliferative zones of newborn ferrets were labeled with tritiated thymidine and a fluorescent dye and were transplanted as a single-cell suspension into the occipital region of newborn ferrets. The transplanted cells became thoroughly integrated into the host environment: many cells migrated through the intermediate zone and into the cortical plate, where they developed as pyramidal neurons. Other transplanted cells came to resemble glial cells. After 1 to 2 months most transplanted neurons had taken up residence in layer 2 + 3, the normal destination of neurons generated on postnatal days 1 and 2. Thus the sequence of morphological differentiation and the eventual laminar position of the isochronically transplanted neurons closely paralleled that of their normal host counterparts.     

Labeling of neural cells by gold-filled Sendai virus envelopes before intracerebral transplantation

Gold-filled Sendai virus envelopes were fused with cell suspensions from the basal forebrain of fetal rat donors, and the resulting gold-labeled cells were transplanted into the neocortex of adult rat recipients. Not only did large numbers of labeled cells remain intact through 3 months in the neocortex, but sizable numbers migrated subcortically to the recipient's lesioned nucleus basalis region (a distance of 4 to 5 millimeters). Since this technique is capable of labeling most transplanted cells for long periods of time, it may be useful in determining the survival, migration, and connectivity of intracerebrally transplanted tissues.     

氮肥运筹对机插大穗型单季稻产量及品质的影响

为了提出适合大穗型杂交稻‘甬优1540’的最佳施肥模式,在机插且总氮施用量为195 kg/hm²条件下,以杂交稻‘甬优1540’为供试材料。在2019年设传统施肥(T1)、机插一次施肥(T2)、机插施肥:分蘖肥7:3(T3)、机插施肥:穗肥7:3(T4)四种氮肥施用模式,研究不同氮肥运筹模式对杂交稻‘甬优1540’产量和主要品质性状的影响。另外增设无氮区处理（磷、钾肥相同）作为对照(CK)。结果表明,穗期追施氮肥(7:3)产量最高。相比于传统施肥,机插施肥:穗肥7:3(T4)处理增加了整精米率、碱消值和胶稠度,降低了直链淀粉含量。说明‘甬优1540’在高产栽培中合理施肥模式为机插施肥:穗肥7:3(T4),该运筹比例有利于稻米品质提高。     

鸡胚胎代用蛋壳及异体胚盘移植孵化的研究

对鸡胚胎蛋壳培养的研究结果显示 :( 1 )在± 4 5°的转角下 ,不同体积的代用蛋壳的胚胎发育率 ,普通蛋代用蛋壳前 6d的胚胎发育率 ( 48.5% )显著高于双黄蛋代用蛋壳 (平均 2 2 .7% ) ,但是 ,双黄蛋代用蛋壳的孵化率 ( 8.3 % )显著高于普通蛋代用蛋壳。普通蛋代用壳无小鸡孵化 ,说明普通蛋壳对于移植等量鸡胚后期的发育空间不够。( 2 )双黄蛋作为代用壳时 ,可以不添加任何物质。( 3 )换蛋壳培养鸡胚胎 ,转蛋角度± 4 5°比± 3 0°的效果要好。异体胚盘移植结果显示 :同一动物间的同功物质具有通用性 ,异体胚盘移植鸡胚可以继续发育。     

Distal regeneration and symmetry

A revision of the "polar coordinate model" shows how pattern formation in diverse regenerating systems can be understood in terms of strictly local cell interactions.     

Transplanted precursors of nerve cells: their fate in the cerebellums of young rats

The multiplying cells of the external granular layer in 7-day-old rats were labeled with [(3)H]thymidine. Slabs of the cerebellum were transplanted into the same region of uninjected hosts of the same age. The transplanted, undifferentiated cells of the donors migrated actively in the cerebellar cortex of the hosts and apparently differentiated there into basket and granule cells.     

Vertebrate regeneration system: culture in vitro

With standard tissue-culture techniques and media, various components of the lizard tail regenerate have been maintained in culture for 8 months. Differentiation of two cell types, melanophores and striated muscle, has been obtained. Myoblast proliferation and fusion can be selectively controlled by altering the culture medium.     

A method for estimating the number of hidden neurons in feed-forward neural networks based on information entropy

The number of hidden neurons of feed-forward neural networks is generally decided on the basis of experience. The method usually results in the lack or redundancy of hidden neurons, and causes the shortage of capacity for storing information or learning overmuch. This research proposes a new method for optimizing the number of hidden neurons based on information entropy. Firstly, an initial neural network with enough hidden neurons should be trained by a set of training samples. Secondly, the activation values of hidden neurons should be calculated by inputting the training samples that can be identified correctly by the trained neural network. Thirdly, all kinds of partitions should be tried and its information gain should be calculated, and then a decision tree for correctly dividing the whole sample space can be constructed. Finally, the important and related hidden neurons that are included in the tree can be found by searching the whole tree, and other redundant hidden neurons can be deleted. Thus, the number of hidden neurons can be decided. Taking a neural network with the best number of hidden units for tea quality evaluation as an example, the result shows that the method is effective.     

Limb regeneration: induction in the newborn opossum

The marsupial Didelphys virginiana (the North American opossumn) is uniquely suited for studies of mammalian limb replacement. By transplanting nervous tissute to the limb, regeneration has been successfully induced in this mammal.     

农村再生与农村永续发展

农村再生与永续发展建设范围及内容涉及生活改善与基础建设、产业发展与工作环境、自然景观与生态环境以及人文社会与文化等4个层面,具整体性、综合性与长久性。台湾农村再生与永续发展之问题主要表现为缺乏农村永续发展整体性内涵之概念和缺乏村民参与农村发展建设之机制。促进农村再生与永续发展,必须确立农村再生与永续发展整体性内涵之概念与架构,加强教育倡导促进村民参与农村再生与永续发展规划,确立整合型农地重划与农村小区范围扩展之意涵,加强农村小区营建规范与建筑管理,长远考虑农村发展规划建设之期程。     

Dynorphin and vasopressin: common localization in magnocellular neurons

The opioid peptide dynorphin is widely distributed in neuronal tissue of rats. By immunocytochemical methods, it was shown previously that dynorphin-like immunoreactivity is present in the posterior pituitary and the cells of the hypothalamic neurosecretory magnocellular nuclei which also are responsible for the synthesis of oxytocin, vasopressin, and their neurophysins. By using an affinity-purified antiserum to the non-enkephalin part of the dynorphin molecule it has now been demonstrated that dynorphin and vasopressin occur in the same hypothalamic cells of rats, whereas dynorphin and oxytocin occur in separate cells. Homozygous Brattleboro rats (deficient in vasopressin) have magnocellular neurons that contain dynorphin separate from oxytocin. Thus dynorphin and vasopressin, although they occur in the same cells, appear to be under separate genetic control and presumably arise from different precursors.     

不同播量对机插水稻群体生长发育及产量的影响

为完善盘锦稻区机插水稻精确定量栽培技术体系,探讨机插秧高产适宜播量。以盐丰47为供试材料,采用小区对比试验,通过设置不同播量处理,测定不同播量对水稻群体生长发育和产量的影响,结果表明,播量为97.5 g/盘的B3处理秧苗素质最好,本田群体生长量适宜,齐穗期和成熟期干物质产量最大,实际产量最高为10.95 t/hm2,比B2、B4、B1、B5处理分别高3.01%、5.80%、8.96%、12.77%。