首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Functional transcrannial Doppler (fTCD) is used for monitoring the hemodynamics characteristics of major cerebral arteries. Its resting-state characteristics are known only when considering the maximal velocity corresponding to the highest Doppler shift (so called the envelope signals). Significantly more information about the resting-state fTCD can be gained when considering the raw cerebral blood flow velocity (CBFV) recordings. In this paper, we considered simultaneously acquired envelope and raw CBFV signals. Specifically, we collected bilateral CBFV recordings from left and right middle cerebral arteries using 20 healthy subjects (10 females). The data collection lasted for 15 minutes. The subjects were asked to remain awake, stay silent, and try to remain thought-free during the data collection. Time, frequency and time-frequency features were extracted from both the raw and the envelope CBFV signals. The effects of age, sex and body-mass index were examined on the extracted features. The results showed that the raw CBFV signals had a higher frequency content, and its temporal structures were almost uncorrelated. The information-theoretic features showed that the raw recordings from left and right middle cerebral arteries had higher content of mutual information than the envelope signals. Age and body-mass index did not have statistically significant effects on the extracted features. Sex-based differences were observed in all three domains and for both, the envelope signals and the raw CBFV signals. These findings indicate that the raw CBFV signals provide valuable information about the cerebral blood flow which can be utilized in further validation of fTCD as a clinical tool.  相似文献   

2.
目的:观察电休克对大鼠空间记忆和海马磷酸化细胞外调节蛋白激酶(p-ERK)活性的影响。方法:大鼠随机分为电休克组和伪电休克组,每组12只。电休克组每天给予电痉挛刺激,伪电休克组每天给予假电痉挛刺激,共10天;第11天用水迷宫检测各组大鼠的空间学习记忆,然后每组大鼠再随机分为两组,每组6只。一组于学习后1小时处死取海马用Western blot法检测p-ERK活性,另一组于48小时后行水迷宫空间位置探寻实验检测大鼠的存储记忆。结果:电休克组的潜伏期显著长于伪电休克组(P0.01)。电休克组在隐匿平台周围区域/相反区域的搜寻时间无显著性差异(P0.05);伪电休克组在隐匿平台周围区域/相反区域的搜寻时间有显著性差异(P0.05)。电休克组海马p-ERK活性较伪电休克组显著下降(P0.01)。结论:电休克可导致大鼠显著空间记忆障碍,海马p-ERK活性的降低可能是其机制之一。  相似文献   

3.
From a fundamental point of view, chemotherapy is the most widely used treatment for cancers despite its side effects on normal cells and tissues. Electrochemotherapy (ECT) is a method for increasing the permeability of cancer cells to drugs and, hence, decreasing their dosage. It apparently creates electropores on the cell membrane using electric pulses. ECT can decrease tumor volume; but this effect is not permanent, and partial regrowth has been reported. The aim of this study was to investigate the potential of magnetic fields in preventing the regrowth of tumors after ECT. Tumoral Balb/c mice were exposed to a magnetic field (15 mT, 50 Hz) for 12 days after treating additionally with 70 V/cm electric pulses and bleomycin at the first day. The magnetic field caused a significant reduction in tumor volumes, while there was no significant difference between the ECT and the electroporation with ECT and magnetic field groups. The exploited magnetic field (15 mT, 50 Hz) could decrease the tumor growth rate significantly, without any effect on ECT efficiency.  相似文献   

4.
Most people are right-handed and left-cerebrally dominant for speech, leading historically to the general notion of left-hemispheric dominance, and more recently to genetic models proposing a single lateralizing gene. This hypothetical gene can account for higher incidence of right-handers in those with left cerebral dominance for speech. It remains unclear how this dominance relates to the right-cerebral dominance for some nonverbal functions such as spatial or emotional processing. Here we use functional magnetic resonance imaging with a sample of 155 subjects to measure asymmetrical activation induced by speech production in the frontal lobes, by face processing in the temporal lobes, and by spatial processing in the parietal lobes. Left-frontal, right-temporal, and right-parietal dominance were all intercorrelated, suggesting that right-cerebral biases may be at least in part complementary to the left-hemispheric dominance for language. However, handedness and parietal asymmetry for spatial processing were uncorrelated, implying independent lateralizing processes, one producing a leftward bias most closely associated with handedness, and the other a rightward bias most closely associated with spatial attention.  相似文献   

5.
The role of structures of the left and right cerebral hemispheres in formation of speech function and memory was studied on the basis of complex examination of children with developmental speech disorders. On the basis of EEG estimation of the functional state of the brain, children were classified in two groups depending on the side of localization of changes in electrical activity: those with local changes in electrical activity in the left hemisphere (group I) and those with changes in the right hemisphere (group II). The medical history suggested that the observed features of topography of local changes in electrical activity were linked with the character of prenatal and labor complications and their consequences leading to embryo- and ontogenetic disorders in development of different brain regions. Comparison of the results of neuropsychological examination of the two groups showed that different regions of the brain cortex of both the left and right hemispheres are involved in speech formation. However, a specific role of the right hemisphere in formation and actualization of automatic speech series was revealed. It was suggested that the integrity of gnostic functions of the right hemisphere and, primarily, the spatial organization of perception and movements is a necessary factor of development of auditory–speech and nominative memory.  相似文献   

6.
Measurements evaluating possible cerebral hemispheric asymmetries were taken by hand on frontal, parietal, and temporal cortex on 60 formalin-fixed Macaca mulatta and Macaca fascicularis brain specimens. No statistically significant (P less than 0.05) right/left side differences in the mean length of four sulci in visual-processing areas of the cortex were found. The sulcus adjacent to the region cytoarchitecturally homologous to the motor speech area in the human brain did not show pronounced asymmetry. In both species, however, a small parietal lobe sulcus showed greater development on the left hemisphere than in the right. In measurements made using digital planimetry, right/left side differences in the area of the dorsal cingulate gyrus were not found. Behavioral evidence suggests that monkeys do not exhibit a consistent pattern of cerebral dominance for functions associated with most of these regions of the brain.  相似文献   

7.

Background

Many patients have serious depression that is nonresponsive to medications, but refuse electroconvulsive therapy (ECT). Early research suggested that isoflurane anesthesia may be an effective alternative to ECT. Subsequent studies altered drug, dose or number of treatments, and failed to replicate this success, halting research on isoflurane''s antidepressant effects for a decade. Our aim was to re-examine whether isoflurane has antidepressant effects comparable to ECT, with less adverse effects on cognition.

Method

Patients with medication-refractory depression received an average of 10 treatments of bifrontal ECT (n = 20) or isoflurane (n = 8) over 3 weeks. Depression severity (Hamilton Rating Scale for Depression-24) and neurocognitive responses (anterograde and retrograde memory, processing speed and verbal fluency) were assessed at Pretreatment, Post all treatments and 4-week Follow-up.

Results

Both treatments produced significant reductions in depression scores at Post-treatment and 4-week Follow-up; however, ECT had modestly better antidepressant effect at follow-up in severity-matched patients. Immediately Post-treatment, ECT (but not isoflurane) patients showed declines in memory, fluency, and processing speed. At Follow-up, only autobiographical memory remained below Pretreatment level for ECT patients, but isoflurane patients had greater test-retest neurocognitive score improvement.

Conclusions

Our data reconfirm that isoflurane has an antidepressant effect approaching ECT with less adverse neurocognitive effects, and reinforce the need for a larger clinical trial.  相似文献   

8.
成敬  李承晏  王高华  陈振华  肖玲 《生物磁学》2013,(27):5230-5233
目的:研究石杉碱甲对电休克模型大鼠记忆和海马活性调节的细胞骨架联合基因(Activity-regulatedcytoskeletal—associatedgene,ARC)表达的影响。方法:大鼠随机分为假电休克对照组和电休克组,再随机分为生理盐水对照组(CS组、ES组)和石杉碱甲组(CH组、EH组)。第l-17天行生理盐水或石杉碱甲灌胃;第8—17天给予假电痉挛刺激或电痉挛刺激;第18天水迷宫定位航线实验;然后各组大鼠随机分成两组,一组取海马用RT.PCR检测ARCmRNA表达,Westem--blot法检测ARC蛋白表达水平,一组于48小时后行水迷宫空间位置探寻实验。结果:电休克导致大鼠显著记忆障碍,ARCmRNA、ARC蛋白表达水平较假电休克对照组显著下降;而石杉碱甲干预的电休克大鼠记忆保持较好,ARCmRNA、ARC蛋白表达水平显著高于生理盐水干预的电休克大鼠,与假电休克大鼠相比无显著性差异。结论:石杉碱甲能减轻电休克模型大鼠记忆损害,其机制可能与海马ARC的表达增加有关。  相似文献   

9.
Physostigmine and other centrally-acting acetylcholinesterase inhibitors are currently being examined for their potential in the treatment of Alzheimer's Disease. The ability to employ this class of agents is limited by the potential for debilitating and dangerous side effects. Clonidine and related drugs have recently been demonstrated to enhance memory performance in monkeys. Clonidine also inhibits the function of cholinergic neurons in specific brain regions and reduces certain side effects of physostigmine. Seven adult macaque monkeys performing a delayed matching-to-sample (DMTS) task received regimens of increasing doses of clonidine and physostigmine on separate occasions to determine the 'best dose' of each agent in terms of enhanced memory performance. The best doses were combined as a single administration and performance compared to that using the two drugs alone. The combination regimen of clonidine and physostigmine was more effective than either drug alone in enhancing memory performance. Part of the benefit may have been due to the ability to employ significantly higher doses of physostigmine in the combination regimen. A single injection of the combination resulted in enhanced performance both on the day of administration as well as on the following day. These results are consistent with the ability of clonidine to limit the expression or intensity of certain physostigmine-induced autonomic side effects, while allowing the cognitive beneficial effects of the cholinesterase inhibitor.  相似文献   

10.
Liu C  Min S  Wei K  Liu D  Dong J  Luo J  Liu XB 《生理学报》2012,64(4):387-402
This study explored the effect of the excitatory amino acid receptor antagonists on the impairment of learning-memory and the hyperphosphorylation of Tau protein induced by electroconvulsive shock (ECT) in depressed rats, in order to provide experimental evidence for the study on neuropsychological mechanisms improving learning and memory impairment and the clinical intervention treatment. The analysis of variance of factorial design set up two intervention factors which were the electroconvulsive shock (two level: no disposition; a course of ECT) and the excitatory amino acid receptor antagonists (three level: iv saline; iv NMDA receptor antagonist MK-801; iv AMPA receptor antagonist DNQX). Forty-eight adult Wistar-Kyoto (WKY) rats (an animal model for depressive behavior) were randomly divided into six experimental groups (n = 8 in each group): saline (iv 2 mL saline through the tail veins of WKY rats ); MK-801 (iv 2 mL 5 mg/kg MK-801 through the tail veins of WKY rats) ; DNQX (iv 2 mL 5 mg/kg DNQX through the tail veins of WKY rats ); saline + ECT (iv 2 mL saline through the tail veins of WKY rats and giving a course of ECT); MK-801 + ECT (iv 2 mL 5 mg/kg MK-801 through the tail veins of WKY rats and giving a course of ECT); DNQX + ECT (iv 2 mL 5 mg/kg DNQX through the tail veins of WKY rats and giving a course of ECT). The Morris water maze test started within 1 day after the finish of the course of ECT to evaluate learning and memory. The hippocampus was removed from rats within 1 day after the finish of Morris water maze test. The content of glutamate in the hippocampus of rats was detected by high performance liquid chromatography. The contents of Tau protein which included Tau5 (total Tau protein), p-PHF1(Ser396/404), p-AT8(Ser199/202) and p-12E8(Ser262) in the hippocampus of rats were detected by immunohistochemistry staining (SP) and Western blot. The results showed that ECT and the glutamate ionic receptor blockers (NMDA receptor antagonist MK-801 and AMPA receptor antagonist DNQX) induced the impairment of learning and memory in depressed rats with extended evasive latency time and shortened space exploration time. And the two factors presented a subtractive effect. ECT significantly up-regulated the content of glutamate in the hippocampus of depressed rats which were not affected by the glutamate ionic receptor blockers. ECT and the glutamate ionic receptor blockers did not affect the total Tau protein in the hippocampus of rats. ECT up-regulated the hyperphosphorylation of Tau protein in the hippocampus of depressed rats, while the glutamate ionic receptor blockers down-regulated it, and combination of the two factors presented a subtractive effect. Our results indicate that ECT up-regulates the content of glutamate in the hippocampus of depressed rats, which up-regulates the hyperphosphorylation of Tau protein resulting in the impairment of learning and memory in depressed rats.  相似文献   

11.
There are many unanswered questions about cerebral lateralization. In particular, it remains unclear which aspects of language and nonverbal ability are lateralized, whether there are any disadvantages associated with atypical patterns of cerebral lateralization, and whether cerebral lateralization develops with age. In the past, researchers interested in these questions tended to use handedness as a proxy measure for cerebral lateralization, but this is unsatisfactory because handedness is only a weak and indirect indicator of laterality of cognitive functions1. Other methods, such as fMRI, are expensive for large-scale studies, and not always feasible with children2.Here we will describe the use of functional transcranial Doppler ultrasound (fTCD) as a cost-effective, non-invasive and reliable method for assessing cerebral lateralization. The procedure involves measuring blood flow in the middle cerebral artery via an ultrasound probe placed just in front of the ear. Our work builds on work by Rune Aaslid, who co-introduced TCD in 1982, and Stefan Knecht, Michael Deppe and their colleagues at the University of Münster, who pioneered the use of simultaneous measurements of left- and right middle cerebral artery blood flow, and devised a method of correcting for heart beat activity. This made it possible to see a clear increase in left-sided blood flow during language generation, with lateralization agreeing well with that obtained using other methods3.The middle cerebral artery has a very wide vascular territory (see Figure 1) and the method does not provide useful information about localization within a hemisphere. Our experience suggests it is particularly sensitive to tasks that involve explicit or implicit speech production. The ''gold standard'' task is a word generation task (e.g. think of as many words as you can that begin with the letter ''B'') 4, but this is not suitable for young children and others with limited literacy skills. Compared with other brain imaging methods, fTCD is relatively unaffected by movement artefacts from speaking, and so we are able to get a reliable result from tasks that involve describing pictures aloud5,6. Accordingly, we have developed a child-friendly task that involves looking at video-clips that tell a story, and then describing what was seen.  相似文献   

12.
Zhou L  Li F  Xu HB  Luo CX  Wu HY  Zhu MM  Lu W  Ji X  Zhou QG  Zhu DY 《Nature medicine》2010,16(12):1439-1443
Stroke is a major public health problem leading to high rates of death and disability in adults. Excessive stimulation of N-methyl-D-aspartate receptors (NMDARs) and the resulting neuronal nitric oxide synthase (nNOS) activation are crucial for neuronal injury after stroke insult. However, directly inhibiting NMDARs or nNOS can cause severe side effects because they have key physiological functions in the CNS. Here we show that cerebral ischemia induces the interaction of nNOS with postsynaptic density protein-95 (PSD-95). Disrupting nNOS-PSD-95 interaction via overexpressing the N-terminal amino acid residues 1-133 of nNOS (nNOS-N(1-133)) prevented glutamate-induced excitotoxicity and cerebral ischemic damage. Given the mechanism of nNOS-PSD-95 interaction, we developed a series of compounds and discovered a small-molecular inhibitor of the nNOS-PSD-95 interaction, ZL006. This drug blocked the ischemia-induced nNOS-PSD-95 association selectively, had potent neuroprotective activity in vitro and ameliorated focal cerebral ischemic damage in mice and rats subjected to middle cerebral artery occlusion (MCAO) and reperfusion. Moreover, it readily crossed the blood-brain barrier, did not inhibit NMDAR function, catalytic activity of nNOS or spatial memory, and had no effect on aggressive behaviors. Thus, this new drug may serve as a treatment for stroke, perhaps without major side effects.  相似文献   

13.
Established therapies for cerebral ischemia-reperfusion injury are currently limited. The urinary trypsin inhibitor ulinastatin (UTI) is considered cytoprotective against ischemia-reperfusion injury in internal organs through its anti-inflammatory activity. We aimed to investigate the neuroprotective effects of UTI on learning and memory of rats after cerebral ischemia-reperfusion injury. Rats were treated with UTI at 10,000 U/kg body weight, then underwent ischemia and reperfusion by the middle cerebral arterial occlusion (MCAO) method. At various times after the onset of reperfusion, we evaluated neurologic impairment scores. Brain sections underwent immunohistochemical staining for synaptophysin and calcium-binding protein S100β. Other rats underwent the Morris water maze test to determine the effects of UTI on learning and memory. Spatial reference learning and memory were improved with UTI treatment by down-regulating S100β-positive cells and preventing the loss of neural cells. Thus, UTI has a neuroprotective role on synaptic plasticity and spatial memory with cerebral ischemia-reperfusion injury in rats.  相似文献   

14.
In nine schizophrenic patients (five males and four females) on haloperidol treatment, plasma and red blood cell (RBC) haloperidol neuroleptic activities were measured before and after ECT by radioreceptor assay. Five patients randomly selected from these patients also served as controls on another occasion and neuroleptic activities in plasma and RBC were examined before and after the premedication only. All patients given ECT showed a considerable increase in plasma and RBC haloperidol neuroleptic activities after ECT (% increase in plasma neuroleptic activity, 28–409%; mean + SD, 136 ± 155%, P<0.005, Wilcoxon test; % increase in RBC neuroleptic activity, 11–121%; mean + SD, 59 ± 40%, P<0.005). However, no significant increase was observed for either plasma or RBC haloperidol neuroleptic activity, when patients were examined after premedication only. It was suggested that ECT induced a transient redistribution of haloperidol. It remains to be studied whether this phenomenon is causally related to the previous observation that the combination therapy of ECT and neuroleptics is more effective in the treatment of schizophrenia than ECT alone.  相似文献   

15.
Despite repeated assertions by some critics of the impossibility of linking behaviour to study of the brain, there have been major, although not always continuous advances in this field over the past 100 years, some of them based on simple techniques. One example is the study of cerebral dominance, for which it was believed until quite recently that no anatomical basis had been specified. The paper summarizes the findings of striking anatomical asymmetry of the upper surface of the temporal lobe, in an area known to be involved in speech functions. Asymmetries observed in autopsy brains of adults and fetuses, both by gross and by cytoarchitectonic techniques, are reported. By use of radiological methods asymmetries have been shown in the brains and skills of living persons. Asymmetries also appear to be present in the endocasts of skulls of ancient humans, and in nonhuman primates. The distribution of asymmetries is different in left and right handers. The implications of these findings are discussed.  相似文献   

16.
人参皂苷Rg2抗MTD大鼠海马神经元凋亡的研究   总被引:1,自引:0,他引:1  
目的:观察多发梗塞性痴呆模型大鼠CPU凋亡相关蛋白的改变,研究其在学习记忆障碍中的作用机制,并探讨人参皂苷Rg2的干预作用。方法:将复合血栓诱导剂经大鼠左颈总-颈内动脉注射入其左侧大脑半球,诱导半球内血栓形成,造成多发梗塞,从而建立大鼠的学习和记忆功能障碍模型。分别给予不同剂量的人参皂苷Rg2治疗7天,并以尼莫地平进行对照。用Y型电迷宫检测正常对照及痴呆模型大鼠学习和记忆能力的改变;对大鼠的脑组织切片作尼氏染色行病理学检查;以免疫组化方法检测Glu、CalpainⅡ、Caspase-3、Bax的表达。结果:颈内动脉注射复合血栓诱导剂可造成大鼠在Y型电迷宫中的学习和记忆成绩明显降低,与假手术对照组比较有显著差异(P<0.05)。尼氏染色可在大鼠脑片的CPU区发现胶质瘢痕化的微梗塞灶。在免疫组化结果中,Glu、CalpainⅡ、Caspase-3、Bax表达均增高。结论:单侧大脑注射复合血栓诱导剂可造成大鼠的学习记忆能力降低,可部分模拟MID的行为和病理学改变。人参皂苷Rg2能明显改善MID模型大鼠的学习记忆成绩,其作用机制可能与它的钙通道阻滞作用使凋亡蛋白CalpainⅡ、Caspase-3、Bax表达降低有关...  相似文献   

17.
目的:探讨体外反搏联合言语训练治疗脑性瘫痪并语言发育迟缓儿童的临床疗效。方法:选择2015年12月至2017年12月在上海市儿童医院康复科普通门诊确诊的脑瘫并语言发育迟缓患儿52例,按照随机数字表法将其随机分为治疗组和对照组,每组26例。对照组仅给予言语训练治疗,治疗组给予体外反搏联合言语训练治,以4周1个疗程,两组均治疗3个疗程。治疗前后,采用中国康复研究中心汉语版儿童语言发育评定法s-s法、Gesell发育评分法评价和比较患儿言语发育商和认知发育商的变化。结果:治疗后,两组言语发育商和认知发育商均显著高于治疗前,且治疗组言语发育商和认知发育商均显著高于对照组,差异均有统计学意义(均P0.01)。结论:体外反搏联合言语训练较单纯言语训练可更有效改善脑瘫并语言发育迟缓患儿的言语发育和认知发育。  相似文献   

18.
It is well described that impairment of energy production has been implicated in the pathogenesis of a number of diseases. Although several advances have occurred over the past 20 years concerning the use and administration of electroconvulsive therapy (ECT) to minimize its side effects, little progress has been made in understanding its mechanism of action. In this work, our aim was to measure the activities of mitochondrial respiratory chain complexes II and IV and succinate dehydrogenase from rat brain after acute and chronic electroconvulsive shock (ECS). Our results showed that mitochondrial respiratory chain enzymes activities were increased after acute ECS in hippocampus, striatum and cortex of rats. Besides, we also demonstrated that complex II activity was increased after chronic ECS in cortex, while hippocampus and striatum were not affected. Succinate dehydrogenase, however, was inhibited after chronic ECS in striatum, activated in cortex and not affected in hippocampus. Finally, complex IV was not affected by chronic ECS in hippocampus, striatum and cortex. Our findings demonstrated that brain metabolism is altered by ECS.  相似文献   

19.
Neurological and cognitive impairment persist in more than 20% of cerebral malaria (CM) patients long after successful anti-parasitic treatment. We recently reported that long term memory and motor coordination deficits are also present in our experimental cerebral malaria model (ECM). We also documented, in a murine model, a lack of obvious pathology or inflammation after parasite elimination, suggesting that the long-term negative neurological outcomes result from potentially reversible biochemical and physiological changes in brains of ECM mice, subsequent to acute ischemic and inflammatory processes. Here, we demonstrate for the first time that acute ECM results in significantly reduced activation of protein kinase B (PKB or Akt) leading to decreased Akt phosphorylation and inhibition of the glycogen kinase synthase (GSK3β) in the brains of mice infected with Plasmodium berghei ANKA (PbA) compared to uninfected controls and to mice infected with the non-neurotrophic P. berghei NK65 (PbN). Though Akt activation improved to control levels after chloroquine treatment in PbA-infected mice, the addition of lithium chloride, a compound which inhibits GSK3β activity and stimulates Akt activation, induced a modest, but significant activation of Akt in the brains of infected mice when compared to uninfected controls treated with chloroquine with and without lithium. In addition, lithium significantly reversed the long-term spatial and visual memory impairment as well as the motor coordination deficits which persisted after successful anti-parasitic treatment. GSK3β inhibition was significantly increased after chloroquine treatment, both in lithium and non-lithium treated PbA-infected mice. These data indicate that acute ECM is associated with abnormalities in cell survival pathways that result in neuronal damage. Regulation of Akt/GSK3β with lithium reduces neuronal degeneration and may have neuroprotective effects in ECM. Aberrant regulation of Akt/GSK3β signaling likely underlies long-term neurological sequelae observed in ECM and may yield adjunctive therapeutic targets for the management of CM.  相似文献   

20.
Sir: For women diagnosed with Recurrent depressive disorder, pregnancy poses a major treatment challenge. Apart from antidepressants, the most commonly used biological therapeutical method is ECT (electroconvulsive therapy). We believe that similar efficacy can be achieved using rTMS as a safer option with substantially less side effects. So far, only a few case-reports reporting the use of rTMS for treatment of pregnant patients with depression were published.  相似文献   

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