Mozart effect in preschool children?

In 1993, Rauscher et al. reported a temporary increase in spatial-temporal ability after listening to Mozart's music. This led to numerous replication and extension studies with mixed findings in the past decade. This study investigated the 'Mozart effect' in preschool children. Forty-one boys and girls, aged three to five, attempted a series of pencil-and-paper maze tests after each of three listening conditions: Mozart's Piano Concerto in A Major (K488), age-appropriate popular music and silence. Overall, there were no statistically significant differences among the three interventions. The results are discussed in relation to the findings of other investigations of the Mozart effect, and the need for further investigation of possible trends.     

Interpretation of skeletal muscle four-electrode impedance measurements using spatial and temporal frequency-dependent conductivities

Spatial and temporal frequency-dependent conductivities are used to interpret four-electrode conductivity measurements on skeletal muscle. The model qualitatively explains the observed dependence of the experimental data on the temporal frequency of the injected current, the angle between the electrode array and the fibre direction and the distance between the electrodes.     

Fooling the brain into thinking it sees both hands moving enhances bimanual spatial coupling

This study examined the hypothesis that the mirror reflection of one hands movement directly influences motor output of the other (hidden) hand, during performance of bimanual drawing. A mirror was placed between the two hands during bimanual circle drawing, with one hand and its reflection visible and the other hand hidden. Bimanual spatial coupling was enhanced by the mirror reflection, as shown by measures of circle size. Effects of the mirror reflection differed significantly from effects of vision to one hand alone, but did not differ from a control task performed in full vision. There was no evidence of a consistent phase lead of the visible hand, which indicates that the observed effects on spatial coupling were immediate and not based on time-consuming feedback processes. We argue that visual mirror symmetry fools the brain into believing it sees both hands moving rather than one. Consequently, the spatial properties of movement of the two hands become more similar through a process that is virtually automatic.     

h载脂蛋白E4/h淀粉样前体蛋白转基因鼠自发变换行为的研究

目的 建立h载脂蛋白E4(h-apo E4)/h淀粉样前体蛋白(h-APP)双转基因鼠模型,探讨人apo E4及人突变APP基因在脂质代谢及早老痴呆疾病(AD)中的作用.方法 将h-apo E4转基因鼠及h-APP转基因鼠交配,建立h-apo E4/h-APP双转基因鼠.通过酶法检测鼠血清胆固醇.Y迷宫检测鼠自发变换行为.结果 经聚合酶链反应初选,Southern杂交进一步鉴定,获得h-apoE4/APP双转基因鼠(10只).h-apo E4/h-APP转基因鼠血清胆固醇水平[9月龄(2.76±0.75)mmol/L,12月龄(3.35±1.23)mmol/L]明显高于同龄对照组鼠(10只)[9月龄(2.03±0.30)mmol/L,12月龄(2.16±0.50)mmol/L](P＜0.05),分别是同龄对照组鼠的1.3倍和1.2倍.12月龄h-APP转基因鼠和h-apo E4转基因鼠血清胆固醇水平[h-APP鼠(2.38±0.37)mmol/L,h-apo E4鼠(2.67±0.59)mmol/L]均明显高于同龄对照组鼠[(2.16±0.5)mmol/L](P＜0.05).转基因鼠自发变换行为[h-apo E4/h-APP(0.74±0.03)%,h-APP(0.80±0.05)%,h-apo E4(0.72±0.07)%]与对照组鼠[(0.95±0.06)%]的差异有统计学意义(P＜0.01或＜0.05).结论 h-apo E4基因与血清胆固醇水平有关,h-apo E4基因及h-APP基因的异常表达对实验鼠的空间记忆能力有影响.     

Neural coding of nociceptive stimuli—from rat spinal neurones to human perception

Translational studies are key to furthering our understanding of nociceptive signalling and bridging the gaps between molecules and pathways to the patients. This requires use of appropriate preclinical models that accurately depict outcome measures used in humans. Whereas behavioural animal studies classically involve reports related to nociceptive thresholds of, for example, withdrawal, electrophysiological recordings of spinal neurones that receive convergent input from primary afferents permits investigation of suprathreshold events and exploration of the full-range coding of different stimuli. We explored the central processing of nociceptive inputs in a novel parallel investigation between rats and humans. Using radiant laser pulses, we first compared the electrophysiological responses of deep wide dynamic range and superficial nociceptive-specific neurones in the rat dorsal horn with human psychophysics and cortical responses. Secondly, we explored the effects of spatial summation using laser pulses of identical energy and different size. We observed 3 main findings. Firstly, both rodent and human data confirmed that neodymium–yttrium aluminium perovskite laser stimulation is a nociceptive-selective stimulus that never activates Aβ afferents. Secondly, graded laser stimulation elicited similarly graded electrophysiological and behavioural responses in both species. Thirdly, there was a significant degree of spatial summation of laser nociceptive input. The remarkable similarity in rodent and human coding indicates that responses of rat dorsal horn neurones can translate to human nociceptive processing. These findings suggest that recordings of spinal neuronal activity elicited by laser stimuli could be a valuable predictive measure of human pain perception.     

A comparative evaluation of the time to frame removal for tibia fractures treated with hexapod and Ilizarov circular frames

IntroductionTraditional Ilizarov and hexapod frames have different biomechanical properties and there is limited literature regarding their effect on time to fracture union or time to frame removal.MethodsTibial fractures managed with a circular frame at a tertiary limb reconstruction referral centre between 2011 and 2018 were retrospectively identified from a prospectively maintained database. They were classified into three treatment groups; Ilizarov style, Taylor Spatial Frame (TSF) and TrueLok Hex (TL-Hex). Data were extracted from electronic patient records and digital radiographs. The primary outcome was time to frame removal, which was seen as an indicator of clinical and radiological fracture union. Odds ratios were calculated with the clinical significance set at 30 days.Results274 patients (median age 49 years, 36% female) were included in the analysis. 8.4% Ilizarov, 10.5% TSF and 13.5% TL-Hex frames required further surgery to aid fracture healing (p = 0.38). 30% of patients had open fractures. Median time to removal for Ilizarov, TSF & TL Hex frames was 167, 198 and 185 days respectively. There was a significant difference between Ilizarov and hexapod frames. Both TSF (OR 2.2, p<0.003) and TL-Hex (OR 1.8, p<0.04) had a significantly increased time to removal of 30 days or more compared with Ilizarov frames.The time to frame removal in metaphyseal fractures was significantly shorter for Ilizarov frame fixation than hexapod frames (p = 0.04). Open fractures were significantly more likely to require at least 30 days extra time to removal than closed fractures (OR 3.3, p<0.001). There was no significant difference in the time to frame removal between fracture location, age or sex.ConclusionIlizarov frames have demonstrated a reduced time to frame removal in the management of tibial fractures than hexapod frames. Differences in the time to frame removal, an indicator of time to fracture union, may be due to the different mechanical properties of the frame, or early disruption of the fracture haematoma through secondary frame manipulation and fracture reduction, increased proportion of metaphyseal fractures treated with Ilizarov, or patient selection. The healing time was comparable across the tibia. Pooled meta-analyses may be able to further quantify these associations.     

慢性阻塞性肺疾病模型大鼠的学习记忆改变及咖啡因的干预作用

目的观察慢性阻塞性肺疾病(COPD)大鼠模型学习记忆的改变,以及不同剂量咖啡因的干预作用。方法通过八臂迷宫训练筛选的SD大鼠,间歇放置于低O2高CO2密闭氧舱4周。咖啡因分两种剂量(30mg/kg和10mg/kg)口服给药。学习记忆的行为学检测先后应用八臂迷宫和Morris水迷宫实验。结果COPD大鼠模型组空间学习记忆能力下降。在八臂迷宫实验中,与对照组相比,COPD模型组的工作记忆错误(WME)为(1.00±1.41)次,增加了50%,参照记忆错误(RME)为(2.83±1.53)次增加了41.5%。咖啡因30mg/kg和10mg/kg干预组WME次数与COPD模型组相比各减少了42%和58%;但咖啡因干预并不能明显减少COPD大鼠的RME。在Morris水迷宫实验中,COPD组训练后3d的总逃避潜伏期都较对照组延长,第5天最明显,延长达32.6%;咖啡因干预组与COPD模型组相比逃避潜伏期均缩短,且第5天明显,其中10mg/kg组缩短了18.7%。结论COPD大鼠空间学习记忆受损,以短时空间记忆受损明显;咖啡因干预可以改善COPD模型的短时空间记忆,慢性咖啡因干预的量效关系不明显。     

Influence of dopamine D3 receptor knockout on age-related decline of spatial memory

There is evidence indicating that the brain's dopaminergic system is involved in age-associated memory impairment. However, specific roles in this process for the different dopamine receptor subtypes have not been elucidated. The cAMP-response element binding protein (CREB) is one of the cellular molecules that have been strongly implicated in the synaptic plasticity deficits occurring in age-related memory and cognitive impairment. In the present study, dopamine D₃ receptor mutant mice were tested in the Morris water maze task. We found that aged D₃ receptor mutant mice perform comparatively better than their even-aged wild-type counterparts in both spatial learning training and a subsequent memory test. The degree of hippocampal CREB phosphorylation is significantly higher in aged D₃ receptor mutants compared to aged wild-type mice, whereas no difference in CREB activation was observed in the prefrontal cortex. These results suggest that blockade of D₃ receptors ameliorates age-related memory decline and that D₃ receptor-regulated CREB signaling in the hippocampus may be involved in these age-associated alterations.     

精神分裂症空间工作记忆任务的fMRI研究

目的采用fMRI技术探讨精神分裂症患者空间工作记忆损害的神经机制。方法收集18例精神分裂症患者和18名正常受试者进行空间n-back任务的fMRI扫描。采用SPM 8进行数据预处理和统计分析,单样本t-检验用于分析两组各自脑激活结果,双样本t-检验用于工作记忆相关脑激活的组间比较。采用FDR方法进行多重比较校正。利用SPSS 17.0软件对工作记忆任务中的行为学结果 (正确率和反应时间)进行组间比较。结果与对照组相比,精神分裂症患者空间工作记忆任务反应时间延长(882.00±50.31)ms,正确率下降(83.60±2.90)%(P0.05)。精神分裂症患者在n-back空间工作记忆任务时所激活的脑区分布与对照组基本一致,主要包括双侧前额皮层、颞顶叶皮层及部分基底核团。但组间比较显示精神分裂症患者多个脑区激活强度及范围明显增加,包括双侧前额皮层背外侧、双侧后顶叶皮层、右侧中央前回、左侧颞中回、右扣带回和双侧小脑(FDR校正,P0.05)。结论执行空间工作记忆任务时精神分裂症患者脑区激活增加,但行为学表现下降,提示患者脑区活动效率低下,可能是工作记忆能力损害的神经基础。