首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5篇
  神经病学   5篇
  2006年   1篇
  2005年   1篇
  2002年   1篇
  2000年   1篇
  1991年   1篇
排序方式: 共有5条查询结果,搜索用时 31 毫秒
1
1.
The distribution of nestin immunoreactivity was studied in the whole normal adult human forebrains using new anti-human nestin mouse monoclonal and rabbit polyclonal antiserum. The nestin immunoreactive cells could be divided into three types according to their morphological characteristics. The first type contained neuron-like nestin immunoreactive cells, distributed in CA1-3 of hippocampus, septum, the nucleus of diagonal band, amygdala and basal nucleus of Meynert. The second type contained astrocyte-like cells, distributed in the subependymal zone and subgranular layer of dentate gyrus. The third type of cells had smaller cell bodies and fewer processes, also distributed in the subependymal zone and subgranular layer of dentate gyrus. Double immunohistochemical staining showed that the nestin positive, neuron-like cells in the nucleus of diagonal band and hippocampus also expressed NSE. However, the astrocyte-like nestin immunoreactive cells of the subependymal zone and subgranular layer of dentate gyrus were not double labeled with GFAP. Although some nestin immunoreactive fibers were distributed in the infundibulum, no nestin-immunoreactive cells were detected in the cortex. These data indicate that nestin exist in the adult human brain outside of the subependymal zone and dentate gyrus and also implies that nestin-immunoreactive cells may play a role in the modulation of basal forebrain function.  相似文献
2.
NMDA receptor-mediated process of rat neocortex slices prepared from 2-24-day-old rats were studied in Mg(2+)-free solution. The response to NMDA application as well as the susceptibility to epileptiform discharges showed age-dependent changes during the first 4 weeks. Slices from the youngest age group seemed to be the most sensitive to NMDA, whereas epileptic activity developed most readily at around the third week.  相似文献
3.
Overexcitation of neuronal networks in some forebrain structures and pathological synchronization of neuronal activity play crucial role in epileptic seizures. Seizure activity can be elicited experimentally by different convulsants. Because of various distribution of excitatory and inhibitory connections in the neocortex there might be laminar differences in seizure sensitivity. Current source density (CSD) analysis or immunocytochemical c-Fos localization offer suitable tools to localize increased activation of neurons during seizure. In the present experiments, interictal epileptiform activity elicited by 4-aminopiridine, bicuculline or Mg(2+)-free solution was recorded with a 16-channel multielectrode assembly in different layers of the somatosensory cortex, and CSDs were calculated. Parallel c-Fos immunocytochemistry was applied. Each convulsant elicited characteristic activation pattern. 4-aminopiridine induced relatively short discharges, which were associated with a huge sink in layer V, the sink and source pattern was relatively simple. Mg(2+)-free solution elicited the longest discharges, sinks appeared typically in the supragranular layers II and III than quickly distributed toward layers V and VI. Bicuculline induced rather similar seizure pattern as Mg(2+)-free solution, but the amplitudes of field potentials were larger, while the durations shorter. The peak of c-Fos activation, however, was not parallel with the largest electrical activation. Larger amount of stained cells appeared in layers II and III in 4-aminopiridine and bicuculline, respectively. In Mg(2+)-free solution the highest c-Fos activity was detected in upper layer VI. Long-lasting cellular effects do not always correspond to the largest electrical responses, which are primarily determined by the activation of asymmetrical pyramidal neurons. Interneurons, which possess more symmetric process arborisation, play less important role in the generation of field potentials, although they may be intensively activated during seizure.  相似文献
4.
Following infraorbital nerve transection, underlying mechanisms of the altered synaptic strength were studied in rat barrel cortex slice experiments. In addition to the in vitro electrophysiological studies, open-field tests were run to detect possible behavioural changes associated with cortical oversensitization. Enhanced NMDA receptor-mediated component of the evoked field response appeared in the barrel cortex after nerve injury. The alteration was transient, very distinct on the first day following injury, and almost returned to normal level by the end of the second week. Behavioural changes had not followed this time-course since long-lasting alterations were detected in the open-field test. These observations are in agreement with findings that showed biphasic regenerative processes following nerve injuries in other cortical areas.  相似文献
5.
The effect of GYKI-52466 (1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine), a selective antagonist of AMPA receptor was investigated on the generation and manifestation of 4-aminopyridine-induced cortical epileptiform activity. In vivo experiments were carried out on pentobarbital-anaesthetised adult rats. Ictal epileptiform activity was induced by local application of 4-aminopyridine (4-Ap) to the surface of somatosensory cortex. In one group of animals, GYKI 52466 was administered intraperitoneally before 4-Ap application, in another group, the already active primary focus was treated locally by GYKI 52466. Different parameters of epileptic activity were measured and compared in GYKI 52466-treated and control animals. The results demonstrate that GYKI 52466 exerts anticonvulsive effects on both the induction and the expression of epileptiform activity, by delaying the onset of the first ictal event, decreasing the numbers and duration of ictal periods, as well as the amplitudes of epileptiform discharges both in the primary and mirror foci. However, seizure propagation to other cortical areas seemed to be facilitated. The anticonvulsive effect of GYKI 52466 was stronger in pretreatment than in treatment of ongoing epileptiform activity. As a conclusion, it is supposed that AMPA receptors are probably more dominant in the induction of epileptiform activity than in the maintenance of it, mainly through the activation of corticothalamo-cortical networks. It is also supposed that the cortical inhibition which blocks the propagation of epileptiform process might be activated mainly through non-N-methyl-D-aspartate receptors.  相似文献
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号