第一和第二语言Stroop任务中EEG同步化分析

采用基于多元自回归的瞬时EEG相干方法研究了十位汉英双语者执行Stroop任务时脑神经电活动及其功能皮层区的协同作用。结果显示：在β1(13-18Hz)频段,无论是汉语(第一语言,L1)还是英语(第二语言,L2)呈现的刺激,不一致条件的EEG相干值明显大于一致条件的EEG相干值,表明β1频段对刺激类型敏感;与L2相比,L1的Stroop任务中,额一顶区的相干值显著增强。EEG相干值反映了不同脑皮层间的相互作用强度。因此研究结果表明：判断和处理冲突信息(如Stroop的不一致条件)时脑功能皮层区之间的协同作用增强;相对于第二语言,第一语言处理过程中额一顶区之间的通信协作增加。     

Gender-related differences in diazepam effects on performance

In order to investigate the possible differences of diazepam effects in the two sexes, two placebo-controlled double-blind studies were conducted on healthy volunteer students. In one study the subjects received diazepam 10 mg alone or combined with 0.5 g/kg of alcohol in a parallel group design; in the other 0.2 mg/kg of diazepam or placebo were given in a cross-over manner. In both trials diazepam impaired the psychomotor skills of women more than men. The difference was similar in tasks measuring cognitive (digit symbol substitution), motor (balance of extraocular muscles) and sensory (critical flicker fusion) performances. Tapping speed was affected to a similar degree in both genders. Diazepam 10 mg did not cause impairment of body balance, a parameter sensitive to alcohol. The combined effect of diazepam and alcohol was of similar magnitude in both sexes in all objective tests. Subjectively the women felt themselves clumsier than did the men. The calming effect was similar in both groups. The results suggest that while the performance of women may be more vulnerable than men to impairment by diazepam they also are aware of it. The difference of effects is of such magnitude that it may cause bias in experiments unless carefully balanced groups are used.     

Gender differences in EEG coherence during memorization of dichotically and monaurally presented verbal stimuli

Gender differences in changes of coherence values in the theta and alpha frequency bands during encoding of dichotically and monaurally presented verbal information were studied. Right-handed students (14 male and 14 female subjects) participated in experiments. The EEG was recorded from 16 electrodes placed at homologous sites of the left and the right hemispheres. In male subjects, numerous differences in coherence values between conditions of dichotical and monaural word presentation were found in the theta2- and alpha1-bands, in females, the differences were most pronounced in the theta1- and theta2-frequency bands. Numerous differences in coherence values differentiated between dichotic and left-sided monaural presentations in males and between dichotic and right-sided monaural presentations in females. As compared to dichotic presentation, in condition of the monaural presentation, higher coherence values were observed in men and lower in women. The features of gender differences in frequency-spatial patterns of changes in EEG coherence values under conditions of bilaterally and unilaterally directed attention in male and female groups may testify that female subjects predominantly use right-hemispheric processing strategy, whereas male subjects use, mainly, left-hemispheric strategy for selection and memorization of concrete nouns.     

Gender-related differences in polyamine oxidase activity in rat tissues

Summary Variations in level of polyamines and their related enzymes are frequently observed in response to some treatments which affect in a different way male and female. The possibility of a gender-related difference in the oxidation of polyamines was investigated in rats by measuring the activity of polyamine oxidase, a ubiquitous enzyme of vertebrate tissues, which transforms spermine into spermidine and spermidine into putrescine. The study was carried out on thymus, spleen, kidney and liver of young rats of both sexes, and female rats showed a lower polyamine oxidase activity than male rats in all the tissues. We also found higher values of spermidine acetylation in female than male rats in thymus and liver. Owing to these gender-related differences, a higher spermidine N-acetyltransferase/ polyamine oxidase ratio was found in female than in male rats. A second gender-related difference was a higher spermidine/spermine ratio in female than in male, the only exception being the thymus. These basal differences possibly account for the gender-related differences of polyamine metabolic enzyme activities in response to some treatments, including drugs or hormones.     

The counting Stroop: a cognitive interference task

The counting Stroop is a validated Stroop task variant. Initially designed as a functional magnetic resonance imaging (fMRI) task for identifying brain regions subserving cognition and attention (dorsal anterior midcingulate cortex (daMCC) and dorsolateral prefrontal cortex (DLPFC)), it has been used to study cognition in healthy volunteers and to identify functional brain abnormalities in neuropsychiatric disorders, such as attention deficit hyperactivity disorder (ADHD). During the counting Stroop, subjects report by button-press the number of words (one to four) appearing on the screen, regardless of word meaning. Neutral-word control trials contain single semantic category common animals (e.g., 'dog' written three times), while interference trials contain number words that are incongruent with the correct response (e.g., 'two' written four times). The counting Stroop can be completed in approximately 20 min per subject and can be used offline (behavioral performance) or with fMRI, positron emission tomography, event-related potentials, magnetoencephalography or intracranial recordings.     

EEG coherence analysis in music listening

Changes in EEG coherence were studied in subjects without special musical education when they were listening to low classic music (below 30 dB). The numbers of significant changes in coherence function in the left and right hemispheres were different. Predominant increase in coherence in the alpha 2, beta 1, and beta 2 frequency ranges was observed in the right temporal-central and parietal-occipital cortical areas. The left-hemispheric coherence was predominantly, decreased on the account of its decrease in the alpha range.     

Gender-related differences in proliferative response of cardiac fibroblasts to hypoxia

Ischemic heart disease is more prevalent in men than in women. The remodeling of extracellular matrix, is a structural correlate of heart failure of ischemic origin and proliferation of cardiac fibroblasts is a key factor in this remodeling. We asked if proliferative response of male and female cardiac fibroblasts is differentially susceptible to hypoxia. DNA synthesis, using 3H-thymidine incorporation was compared under hypoxia (2% O₂) in cardiac fibroblasts obtained from adult, age-matched male and female rat heart. In female cells DNA synthesis remained unchanged under hypoxia and this resistance was dependent on tyrosine kinase activation, as it was abolished in the presence of genistein, a tyrosine kinase inhibitor. Male cells, on the other hand, were susceptible to hypoxia and their DNA synthesis was reduced significantly (70%, (p < 0.0001). This effect was partially reversed by inhibition of tyrosine kinase. Western analysis showed a higher abundance of tyrosine phosphorylated proteins in male cells compared to female cells as well as differences in molecular weight of basal and hypoxia-induced tyrosine-phosphorylated proteins between male and female cells. The presence of estrogen (17- estradiol, 10 nM) altered the response of both cells to hypoxia. In female cells the combined effect of hypoxia and estrogen led to inhibition of DNA synthesis, whereas in male cells estrogen partially reversed the hypoxia-induced inhibition of DNA synthesis (37% (p < 0.01) inhibition in the presence of estrogen vs. 70% (p < 0.0001) inhibition in the absence of estrogen). The effects of estrogen in male and female cells were mediated via estrogen receptors as they were reversed by the pure anti-estrogen, ICI 182,780. Western analysis of cell lysate showed hypoxia-induced increase in the level of estrogen receptor in both male and female cells. Gel shift analysis showed hypoxia-induced increase in cytoplasmic ERE (estrogen response element)-binding activity and decrease in nuclear ERE-binding in male cells. In female cells cytoplasmic and nuclear ERE-binding activities remained unchanged under hypoxia. Together, these data demonstrate that while female cells are resistant to hypoxia-induced inhibition in DNA synthesis, male cells are susceptible; intracellular pathways involving tyrosine phosphorylation are involved in the response of both cells; and estrogen, via estrogen-receptor-dependent mechanisms, differentially alters the response of male and female cells to hypoxia.     

Gender-related differences in the dysfunctional resting networks of migraine suffers

Background

Migraine shows gender-specific incidence and has a higher prevalence in females. However, little is known about gender-related differences in dysfunctional brain organization, which may account for gender-specific vulnerability and characteristics of migraine. In this study, we considered gender-related differences in the topological property of resting functional networks.

Methodology/Principal Findings

Data was obtained from 38 migraine patients (18 males and 20 females) and 38 healthy subjects (18 males and 20 females). We used the graph theory analysis, which becomes a powerful tool in investigating complex brain networks on a whole brain scale and could describe functional interactions between brain regions. Using this approach, we compared the brain functional networks between these two groups, and several network properties were investigated, such as small-worldness, network resilience, nodal centrality, and interregional connections. In our findings, these network characters were all disrupted in patients suffering from chronic migraine. More importantly, these functional damages in the migraine-affected brain had a skewed balance between males and females. In female patients, brain functional networks showed worse resilience, more regions exhibited decreased nodal centrality, and more functional connections revealed abnormalities than in male patients.

Conclusions

These results indicated that migraine may have an additional influence on females and lead to more dysfunctional organization in their resting functional networks.     

Interhemispheric differences in the spectral power and coherence of EEG rhythms in children with autism spectrum disorders

Electroencephalographic examination of boys aged 4–9 years with autism spectrum disorders (ASDs) showed spectral power values and coherence in high-frequency bands (20–60 Hz) in various brain areas were higher than normal. Differences in spectral power were greater in the anterior areas of the left hemisphere; differences in coherence, in the right anterior and posterior areas. Interhemispheric differences typical of healthy subjects were absent in the children with ASDs. The spectral power of the θ rhythm was lower in autism, especially in the left hemisphere. The spectral power of the α rhythm in the autistic children was lower than normal, especially in the posterior areas of the left hemisphere. The μ rhythm was higher than normal in spectral power and was localized in the right, rather than left, anterior areas. The children were examined again after corrective procedures. The α-rhythm spectral power increased (became closer to the norm) in the left posterior areas, while the γ-rhythm spectral power decreased (became closer to the norm) in the right anterior areas in some of the autistic children. The electrophysiological changes were associated with improved psychological testing results, especially in nonverbal measures.     

兔LQT2模型心室肌复极化的性别差异

本研究旨在探讨长QT综合征（long QT syndromes,LQTS）室性心律失常发生的性别差异及其电生理机制,初步观察了不同性别兔LQT2模型左心事原已存在的电生理异质性和心事复极动力学的特征。实验分为3组,上下常组以标准台氏液灌流;LQT2模型组给予含100gmol／L dl-sotalol的台式液灌流;LQT2模型＋低钾组给了含3．0mmol／LKCl、100μmol／L dl-sotalol的台式液灌流。采用冠状动脉旋支灌注兔左室心肌楔形组织块标本,应用浮置玻璃微电极记录技术进行记录。给予基础刺激周长（basic cycle length,BCL）为500、l000和2000ms的S1刺激,同步记录心事肌内膜侧、外膜侧细胞动作电位,并记录跨壁心电图：在BCL为500和1000ms时加用S2程序刺激以记录动作电位时程（action potential duration,APD）恢复曲线。研究发现：在不同刺激频率时,3组实验雌兔心肌细胞的跨壁复极化离散（transmural dispersion of repolarization,TDR）、APD恢复曲线斜率均大于雄兔,有显著性差异（P〈0．05）,并呈频率依赖性;LQT2模型组及LQT2模型＋低钾组雌雄兔TDR、APD恢复曲线斜率较正常组明显增人（P〈0．01）。BCL为1000ms时,LQT2模型组雌兔7例中1例发生尖端扭转性窀性心动过速（torsade de pointes,TdP）;LQT2模型＋低钾组雌兔7例中5例诱发TdP,雄兔7例中2例诱发TdP,有显著性差异（P〈0．05）。结果提示：LQT2模型心肌原已存在的电生理异质性和动态异质性均有明显的性别差异,并≯频率依赖性。存LQT2模型中,TDR以及APD恢复曲线斜率的增大可能是雌性动物较雄性更易发生尖端扭转性心律失常的原因。     

Gender-related differences in elite gymnasts: the female athlete triad.

High-intensity training can alter the normal pattern of pubertal development in elite gymnasts. We investigated sex hormones, the ob gene product leptin, body composition, nutrition, and eating habits in female and male elite gymnasts from national cadres to elucidate gender-related differences. Serum leptin levels were decreased, particularly in pubertal girls, and did not show the normal developmental pattern. After leptin levels were transformed into standard deviation scores, mainly pubertal female gymnasts had significantly lower values than normal controls of the same gender, pubertal stage, and body mass index. The percentage of body fat was reduced compared with a normal age-matched population in both genders but to a higher degree in female gymnasts. When leptin standard deviation scores were based on percent body fat instead of body mass index, mean values were still significantly decreased compared with those of normal controls: -1.05 in girls (P < 0.001) and -0.60 in boys (P = 0.025). In both genders, total energy consumption and nutritional intake were insufficient, although to a lesser extent in male gymnasts. Pubertal development is influenced to a different degree in female and male elite gymnasts. In contrast to their male counterparts, high-intensity training takes place during the sensitive phase of pubertal maturation in female gymnasts. Whereas the girls displayed low estrogen levels, hypoleptinemia, reduced body fat mass, insufficient caloric intake, and retarded menarche, the pubertal development of male gymnasts remained almost unaltered.     

Spontaneous eyeblinks are correlated with responses during the Stroop task

The timing and frequency of spontaneous eyeblinking is thought to be influenced by ongoing internal cognitive or neurophysiological processes, but how precisely these processes influence the dynamics of eyeblinking is still unclear. This study aimed to better understand the functional role of eyeblinking during cognitive processes by investigating the temporal pattern of eyeblinks during the performance of attentional tasks. The timing of spontaneous eyeblinks was recorded from 28 healthy subjects during the performance of both visual and auditory versions of the Stroop task, and the temporal distributions of eyeblinks were estimated in relation to the timing of stimulus presentation and vocal response during the tasks. We found that the spontaneous eyeblink rate increased during Stroop task performance compared with the resting rate. Importantly, the subjects (17/28 during the visual Stroop, 20/28 during the auditory Stroop) were more likely to blink before a vocal response in both tasks (150-250 msec) and the remaining subjects were more likely to blink soon after the vocal response (200-300 msec), regardless of the stimulus type (congruent or incongruent) or task difficulty. These findings show that spontaneous eyeblinks are closely associated with responses during the performance of the Stroop task on a short time scale and suggest that spontaneous eyeblinks likely signal a shift in the internal cognitive or attentional state of the subjects.     

Association of lucid dreaming frequency with Stroop task performance.

Lucid dreaming involves the attentional skill of having metacognition about the dreamer's state of consciousness at the same time as being engaged in the dream scenario. A combination of two levels of cognition also occurs in the incongruent condition of the Stroop task, where there is interference between the attentional demands of a relatively difficult (color naming) and an easy (reading) task. It was thus hypothesized that frequent lucid dreamers would perform better on the Stroop task than would nonlucid dreamers. Individuals who reported having lucid dreams more than once per month (n = 15) were found to be significantly faster on the incongruent condition of the Stroop task than were occasional lucid dreamers (n = 15) or nonlucid dreamers (n = 15). The groups did not differ on the standard colored nonword control condition. Continuity in attentional ability between waking and dreaming cognition was thus found. This continuity may counteract the psychophysiologically dominant and possibly evolutionarily selected lack of self-awareness in dreams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender-related differences in susceptibility to oxidative stress in healthy middle-aged Serbian adults

Gender-related differences in the association between polymorphism of xenobiotic-metabolising enzymes or non-genetic biomarkers and susceptibility to oxidative stress was assessed in healthy middle-aged Serbian adults, by urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG/creatinine) and total antioxidant status in serum (TAOS). Females were more susceptible to oxidative stress. In both genders, positive predictor of the antioxidative protection was serum triglyceride, while BMI?<25?kg/m² was associated with oxidative stress. Susceptibility to oxidative stress in males was associated with GSTT1*null allele and increased serum iron, but in females, it was decreased serum bilirubin. Early identification of the risk factors could be important in the prevention of oxidative stress-related diseases.     

Gender-related differences in the oxidant state of cells in Fanconi anemia heterozygotes

Abstract Fanconi anemia (FA) is a rare cancer-prone genetic disorder characterized by progressive bone marrow failure, chromosomal instability and redox abnormalities. There is much biochemical and genetic data, which strongly suggest that FA cells experience increased oxidative stress. The present study was designed to elucidate if differences in oxidant state exist between control, idiopathic bone marrow failure (idBMF) and FA cells, and to analyze oxidant state of cells in FA heterozygous carriers as well. The results of the present study confirm an in vivo prooxidant state of FA cells and clearly indicate that FA patients can be distinguished from idBMF patients based on the oxidant state of cells. Female carriers of FA mutation also exhibited hallmarks of an in vivo prooxidant state behaving in a similar manner as FA patients. On the other hand, the oxidant state of cells in FA male carriers and idBMF families failed to show any significant difference vs. controls. We demonstrate that the altered oxidant state influences susceptibility of cells to apoptosis in both FA patients and female carriers. The results highlight the need for further research of the possible role of mitochondrial inheritance in the pathogenesis of FA.     

Gender-related differences in drug effects: The role of multidrug resistance proteins

Mechanisms of the involvement of multidrug resistance proteins (MRPs) in the formation of gender-related differences in drug effectiveness and adverse effects have been analyzed. The structure, tissue and cellular localization, substrate specificity, and functions of MRPs are discussed. The regulation of MRP expression and activity by endogenous metabolites, signaling compounds, including sex hormones, and pharmaceutical agents is described. Nuclear receptors have been shown to play a role in the regulation of MRP expression. Data on gender-related differences in the expression of MRPs and nuclear receptors that are involved in the induction of MRPs in the liver and kidney are presented. It is concluded that gender-related differences in the expression and functional activity of MRPs in excretory organs (the liver and kidney) may significantly contribute to gender dependence of drug pharmacokinetics and effectiveness.     

Gender-related differences in myocardial inflammatory and contractile responses to major burn trauma

Gender-related differences in immune responses to hemorrhage and sepsis have been described. However, most trauma studies continue to limit experimental models to males to avoid the variable responses associated with hormonal fluctuation in proestrus/estrus females. In the present study, male and female (either diestrus or proestrus/estrus) Sprague-Dawley rats (250-325 g) were given a third-degree scald burn over 40% total body surface area and fluid resuscitated (4 ml/kg per %burn of lactated Ringer solution); sham burn males and diestrus as well as sham burn proestrus/estrus female rats were included to provide controls. Twenty-four hours postburn, hearts were either perfused to examine mechanical function (Langendorff, n = 8 to 9 hearts/group) or to prepare cardiomyocytes (collagenase digestion, n = 4 to 5 hearts/group). Left ventricular developed pressure and the positive and negative first derivative of left ventricular pressure responses to increases in preload were significantly lower in burned males compared with responses measured in either burned proestrus/estrus or burned diestrus females; burn trauma increased cardiomyocyte secretion of tumor necrosis factor-alpha, interleukin-1beta, and nitric oxide to a lesser extent in proestrus/estrus females than levels secreted by either diestrus females or males. Similarly, myocytes from proestrus/estrus females accumulated significantly less sodium/calcium compared with values measured in males (P < 0.05). Our data confirm gender-related differences in myocardial function and myocardial inflammatory responses to burn injury.