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41.
The early maintenance of long-term potentiation (LTP) was studied in the CA1 region of hippocampal slices from 12- to 18-day-old rats in a low-magnesium solution (0.1 mM). The α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor-mediated components of the field excitatory postsynaptic potential were estimated in parallel using early and late measurements of the composite potential. At the normal test stimulus frequency of 0.1 Hz, LTP was seen initially as a predominant increase in the AMPA component, but converted, via a substantial decay of this component and a gradual growth of the NMDA component, into nearly equal changes of the two components. Interrupting the test stimulation for 10 min, changing the test stimulus frequency to 1/60 Hz after LTP induction, or using a test stimulus frequency of 1/60 Hz during the entire experiment significantly reduced the decay of the potentiation of the AMPA component while enhancing the potentiation of the NMDA one. The ratio between the magnitudes of the two excitatory postsynaptic potential (EPSP) components showed a decaying time course that was independent of the manipulations used. Application of the NMDA antagonist D(-)-2-amino-5-phosphonopentanoic acid (50μM) after LTP induction stabilized the LTP of the AMPA component until washout was started. On the other hand, the phosphatase inhibitor okadaic acid (1 μM) resulted in decay of the potentiation of both EPSP components back to around baseline and altered the time course of the ratio between the components. Our results show that the early maintenance of LTP is controlled in an activity-dependent and NMDA-dependent manner. This process accelerates the decay of LTP of both AMPA and NMDA components in parallel, suggesting that it is similar to homosynaptic long-term depression, although it operates at the normal test stimulus frequency. The data support a scenario in which LTP ensues as a selective AMPA receptor modification and subsequently converts to another modification, possibly a presynaptic one. 相似文献
42.
Sheryl Brennan 《Nursing inquiry》1998,5(1):11-17
The present paper addresses the relationship between community based child health nursing services and social constructions of motherhood within Australia during the 1920s. Following the First World War, child health nursing services (then generally known as infant welfare or child welfare services) were established in all Australian states. The focus of the paper is mainly upon the development of the Tasmanian child health service, with some reference to similar services in other states. Within two decades of their establishment, most child-bearing women in Tasmania were in contact with child health services and this apparent success meant that, thereafter, women in Tasmania cared for their children under the 'expert' guidance of nurses. As the 1920s progressed, child health nurses increasingly promoted one particular, and ultimately extremely influential, construction of motherhood, 'scientific motherhood', based upon the philosophy of Dr Truby King. I argue that an understanding of how nursing services have historically reinforced and promoted ideological constructions of motherhood enhances the practice of present day nurses working with women. This argument is supported by reference to present day nursing practice in relation to postnatal depression. 相似文献
43.
E. Isometsa M. Heikkinen M. Henriksson M. Marttunen H. Aro J. Lonnqvist 《Acta psychiatrica Scandinavica》1997,95(4):297-305
As part of a nation-wide psychological autopsy we examined the differences in DSM-III-R mental disorders, recent life events and other characteristics between urban (n=143) and rural (n=85) completed suicides in a random sample of 229 cases from the National Suicide Prevention Project in Finland for the period 1987-1988. Psychoactive substance use disorders (48% vs. 34%), cluster B personality disorders (24% vs. 9%) and psychiatric comorbidity (66% vs. 42%) were found more commonly among urban than rural suicides. Urban suicides were also more often reported to be preceded by a recent separation (25% vs. 8%), whereas rural suicide victims tended to have lacked a close companion of the opposite sex (36% vs. 18%) and to have had physical disorders (56% vs. 40%). Overall, urban and rural suicides may vary with regard to the prevalence of some mental disorders, their comorbidity, and physical disorders, as well as the preceding life situation. This variation may also imply the need for differences in strategies for suicide prevention in each setting. 相似文献
44.
45.
C. M. A. Pennartz R. F. Ameerun H. J. Groenewegen F. H. Lopes da Silva 《The European journal of neuroscience》1993,5(2):107-117
Extra- and intracellular recordings in slices were used to examine what types of synaptic plasticity can be found in the core of the nucleus accumbens, and how these forms of plasticity may be modulated by dopamine. Stimulus electrodes were placed at the rostral border of the nucleus accumbens in order to excite primarily infralimbic and prelimbic afferents, as was confirmed by injections of the retrograde tracer fluoro-gold. In extracellular recordings, tetanization induced long-term potentiation (LTP) of the population spike in 20 out of 53 slices. The presynaptic compound action potential did not change following LTP induction. For the intracellularly recorded excitatory postsynaptic potential, three types of synaptic plasticity were noted: long-term potentiation (16 out of 54 cells), decremental potentiation (eight cells) and long-term depression (LTD; six cells). No correlation was found between the occurrence of potentiation or depression and various parameters of the tetanic depolarization (e.g. peak voltage, integral under the curve). The N -methyl- d -aspartate receptor antagonist d (–)-2-amino-5-phosphonopentanoic acid (50 μM; d -AP5) reduced, but did not completely prevent, the induction of LTP. The incidence of LTD was not markedly affected by d -AP5. No difference in LTP was found when comparing slices bathed in dopamine (10 μM) and controls. Likewise, slices treated with a mixture of the D1 receptor antagonist Sch 23390 (1 μM) and the D2 antagonist S (–)-sulpiride (1 μM) generated a similar amount of LTP as controls. In conclusion, both LTP and LTD can be induced in a key structure of the limbic-innervated basal ganglia. LTP in the nucleus accumbens strongly depends on N -methyl- d -aspartate receptor activity, but is not significantly affected by dopamine. 相似文献
46.
Symptom Clusters in Patients With High-Grade Glioma 总被引:2,自引:0,他引:2
47.
Christopher R Pryce Andrea C Dettling Marianne Spengler Christian R Schnell Joram Feldon 《Neuropsychopharmacology》2004,56(2):72-79
BACKGROUND: Early environment is a major determinant of long-term mental health, evidenced by the relationship between early-life neglect or abuse and chronically increased vulnerability to developmental psychopathology, including major depressive disorder (MDD). Animal studies can increase understanding of environmentally mediated causal risk processes. We describe how daily deprivation of biological parenting in primate infants disrupts development of homeostatic and reward systems central to MDD. METHODS: Nine breeding pairs of marmoset monkeys provided control twins (CON) and early-deprived twins (ED); the latter were socially isolated for 30-120 min/day on days 2-28. During the first year of life, basal urinary norepinephrine (NE) titers and cardiophysiologic activity were measured. At the end of year 1 (adolescence), automated neuropsychologic tests were conducted to measure responsiveness to changes in stimulus-reward association (simple/reversed visual discrimination learning) and to reward per se (progressive ratio [PR] reinforcement schedule). RESULTS: The ED monkeys exhibited increased basal urinary NE titers and increased systolic blood pressure relative to CON siblings. The ED monkeys required more sessions to reinstate stimulus-oriented behavior following reversal, suggesting increased vulnerability to perceived loss of environmental control; ED monkeys also performed less PR operant responses, indicating that reward was less of an incentive and that they were mildly anhedonic relative to CON. CONCLUSIONS: In marmoset monkeys, neglect-like manipulation of ED leads to chronic changes in homeostatic systems, similar to those in children and adolescents exposed to early-life adversity and in MDD, and to responses to environmental stimuli similar to those that characterize MDD. 相似文献
48.
抑郁障碍对血液透析患者的影响 总被引:1,自引:0,他引:1
目的 探讨尿毒症患者产生抑郁障碍的可能因素及其对血液透析的影响,并尝试药物治疗,改善患者的生活质量。方法 选择无精神病史的规律性血透患者51例,进行汉密尔顿抑郁量表(HAMD,24项版本)评分,并分为抑郁组和非抑郁组;在组间进行性别、年龄、文化程度和经济状况的比较,观察患者透析充分性、营养、就业率及顺应性在组间的差异。选择重度抑郁状态者予博乐欣(75-150mg/d)抗抑郁治疗,观察疗效。结果 (1)35.3%的患者存在抑郁障碍;(2)两组的年龄、性别、文化程度和婚姻障碍情况均无显著差异;(3)两组间在医疗付费方式、透前规律性肾科门诊及顺应性、充分性、营养状态方面存在显著差异;(4)在18例中选7例抗抑郁治疗,1个月后HAMD评分均有不同程度下降。结论 抑郁障碍在血透患者中是常见的。它可造成血透患者的顺应性下降、营养不良、透析不充分等。抗抑郁的药物治疗可望改善患者的抑郁状态。 相似文献
49.
在53只乌拉坦麻醉家兔身上,观察到延髓孤束核(NTS)区注射γ-氨基丁酸(GABA)使血压显著下降,安定(DZ)有相似的降压效应,荷包牡丹碱(BIC)和印防己毒素(PIC)则使血压升高;促甲状腺素释放激素(TRH)和甲硫脑啡肽(MTP)对血压无明显影响;延髓的另一些区域应用GABA等药物后血压变化不明显;提示GABA能神经递质系统参与心血管活动的抑制性中枢调节,NTS区是其作用部位之一。 相似文献
50.
Birgit Herting MD Bettina Beuthien‐Baumann MD Katrin Pöttrich PhD Markus Donix MD Antje Triemer PhD Johannes B. Lampe MD Rüdiger von Kummer MD Karl Herholz MD Heinz Reichmann MD Vjera A. Holthoff MD 《Movement disorders》2007,22(4):490-497
Depressive symptoms are common in patients with neurodegenerative disorders. Imaging studies suggest that a disruption of frontal-subcortical pathways may underlie depression associated with basal ganglia disease. This pilot study tested the hypothesis that frontal dysfunction contributes to depression associated with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Depressed patients with MSA (n = 11), PSP (n = 9), and age-matched controls (n = 25) underwent measures of cerebral glucose metabolism applying positron emission tomography with (18)F-fluorodeoxyglucose. Regional metabolism in the patient groups was compared to the normal subjects using the voxel-based statistical parametric mapping. Depressive symptom severity (Hamilton Depression Rating) and degree of locomotor disability (Hoehn & Yahr) were assessed in the patient groups. The association between prefrontal metabolism and the occurrence of depressive symptoms and the degree of locomotor disability was investigated. When compared to controls, MSA patients revealed significant metabolic decreases in bilateral frontal, parietal, and cerebellar cortex and in the left putamen. In PSP patients, significant hypometabolism was demonstrated in bilateral frontal cortex, right thalamus, and midbrain. Depression severity but not the patients' functional condition was significantly associated with dorsolateral prefrontal glucose metabolism in both patient groups. The findings of this pilot study support the hypothesis that depressive symptoms in MSA and PSP are associated with prefrontal dysfunction. 相似文献