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31.
Cortex-restricted disruption of NMDAR1 impairs neuronal patterns in the barrel cortex 总被引:14,自引:0,他引:14
Iwasato T Datwani A Wolf AM Nishiyama H Taguchi Y Tonegawa S Knöpfel T Erzurumlu RS Itohara S 《Nature》2000,406(6797):726-731
In the rodent primary somatosensory cortex, the configuration of whiskers and sinus hairs on the snout and of receptor-dense zones on the paws is topographically represented as discrete modules of layer IV granule cells (barrels) and thalamocortical afferent terminals. The role of neural activity, particularly activity mediated by NMDARs (N-methyl-D-aspartate receptors), in patterning of the somatosensory cortex has been a subject of debate. We have generated mice in which deletion of the NMDAR1 (NR1) gene is restricted to excitatory cortical neurons, and here we show that sensory periphery-related patterns develop normally in the brainstem and thalamic somatosensory relay stations of these mice. In the somatosensory cortex, thalamocortical afferents corresponding to large whiskers form patterns and display critical period plasticity, but their patterning is not as distinct as that seen in the cortex of normal mice. Other thalamocortical patterns corresponding to sinus hairs and digits are mostly absent. The cellular aggregates known as barrels and barrel boundaries do not develop even at sites where thalamocortical afferents cluster. Our findings indicate that cortical NMDARs are essential for the aggregation of layer IV cells into barrels and for development of the full complement of thalamocortical patterns. 相似文献
32.
Mark C. Hove Bernard E. Sietman Matthew S. Berg Erika C. Frost Kiru Wolf Tony R. Brady 《Journal of Natural History》2016,50(9-10):523-542
Managing a rare species can be improved with knowledge of its natural history. The sheepnose (Plethobasus cyphyus) is a freshwater mussel recently listed by the US as federally endangered. We used standard methods to study P. cyphyus brooding behaviour, host fishes in the laboratory and under natural conditions, and glochidial morphology. We monitored a population of P. cyphyus in the Chippewa River, WI during spring and summer 2007–2009 and 2011 and found brooding animals between mid-May and early August. Gravid individuals ranged between 5 and 27 yr (mean age ± 1 s.d. = 13 ± 4 yr). Plethobasus cyphyus brooded glochidia in outer gills, which varied in colour from red, orange, pink, cream, or white. We observed mature glochidia more commonly in individuals with cream or white gills and these glochidia were released in a clear, adhesive, mucus matrix. In laboratory trials we found several minnow and topminnow species (29 spp.) served as productive suitable native hosts. The mean number of juvenile mussels released per cyprinid per day was significantly higher for trials conducted at 22–25°C compared with those at 18–20°C, and 83% of trials conducted at 18–20°C using suitable host species produced no juveniles. Glochidia had a unique outline and shell morphometrics that distinguished P. cyphyus from seven other Chippewa River mussel species that produce similar sized glochidia. Using morphometrics we determined that mimic shiners (Notropis volucellus) were natural hosts for P. cyphyus, round pigtoe (Pleurobema sintoxia), and Wabash pigtoe (Fusconaia flava). Releasing mucus-bound glochidia has evolved in a variety of mussel species and may be more common than is currently realized. Our data show that P. cyphyus is a cyprinid host specialist, and propagation efforts for this species can be strengthened through improved access to mature glochidia by using females with cream-coloured gills and increased juvenile production through warmer fish holding temperatures. 相似文献
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K. Rácz I. Wolf R. Kiss Gy. Lada S. Vida E. Gláz 《Cellular and molecular life sciences : CMLS》1979,35(11):1532-1534
Summary The direct effect of serotonin and antiserotonin agents on adrenal steroid biosynthesis was studied in isolated adrenal cells derived from patients with Cushing's syndrome. The results indicate that serotonin increases corticosterone production, while the serotonin antagonists cyproheptadine and methysergide depress adrenal steroid-particularly cortisol and aldosterone-biosynthesis.The authors are indebted to Dr. M. Kárteszi, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, for the determination of plasma ACTH by radioimmunoassay in our patients, and to Prof. P. Vecsei, Department of Pharmacology, University of Heidelberg, providing us with highly specific antisera for corticosteroids RIA-s. 相似文献
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H Wolf 《Experientia》1987,43(11-12):1189-1192
Molecular biology allowed considerable improvements in diagnostic procedures by production of new and more specific sonds for the detection of traces of viruses, both on the nucleic acid and protein levels, and by determining the immune response of the host to specific antigens. Improvements in sensitivity and improved correlation to the stage of viral disease are already evident from several applications and strongly suggest a broad application of these approaches. 相似文献
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Constância M Hemberger M Hughes J Dean W Ferguson-Smith A Fundele R Stewart F Kelsey G Fowden A Sibley C Reik W 《Nature》2002,417(6892):945-948