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Summary The effects of i.p. injections of amphetamine and apomorphine were determined before and after unilateral ligation of the carotid artery in the gerbil. Significant increases in turning behavior were observed in the absence of neurohistological evidence of infarction.  相似文献   
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The highly reduced genome of an enslaved algal nucleus   总被引:34,自引:0,他引:34  
Chromophyte algae differ fundamentally from plants in possessing chloroplasts that contain chlorophyll c and that have a more complex bounding-membrane topology. Although chromophytes are known to be evolutionary chimaeras of a red alga and a non-photosynthetic host, which gave rise to their exceptional membrane complexity, their cell biology is poorly understood. Cryptomonads are the only chromophytes that still retain the enslaved red algal nucleus as a minute nucleomorph. Here we report complete sequences for all three nucleomorph chromosomes from the cryptomonad Guillardia theta. This tiny 551-kilobase eukaryotic genome is the most gene-dense known, with only 17 diminutive spliceosomal introns and 44 overlapping genes. Marked evolutionary compaction hundreds of millions of years ago eliminated nearly all the nucleomorph genes for metabolic functions, but left 30 for chloroplast-located proteins. To allow expression of these proteins, nucleomorphs retain hundreds of genetic-housekeeping genes. Nucleomorph DNA replication and periplastid protein synthesis require the import of many nuclear gene products across endoplasmic reticulum and periplastid membranes. The chromosomes have centromeres, but possibly only one loop domain, offering a means for studying eukaryotic chromosome replication, segregation and evolution.  相似文献   
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Cellular and Molecular Life Sciences - Le comportement des rats a été fortement influencé par des dérivés de la 2,5-diméthoxyamphétamine Le mécanisme...  相似文献   
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J M Beaton 《Experientia》1976,32(8):1036-1037
The activity of 5 groups of gerbils was monitored over 22 days. 3 of the groups received daily injections of nicotinamide (125, 250 or 500 mg/kg) and a 4th group received saline. The 5th group was untreated. The results indicated that both the 250 and 500 mg/kg nicotinamide administrations greatly reduced the activity levels of the gerbils.  相似文献   
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