Alcohol exposure during the first two trimesters-equivalent alters the development of corpus callosum projection neurons in the rat.

Children exposed prenatally to alcohol can display a variety of neural deficits, including an altered development of the corpus callosum (CC), the largest interhemispheric axon pathway in the brain. Furthermore, these children show functional abnormalities that are related to brain regions with significant numbers of CC connections. Little is known about how alcohol imparts influence on CC development, but one possible mechanism is by affecting the corpus callosum projection neurons (CCpn) directly. The purpose of this study was to quantify the effects of prenatal alcohol exposure on the number, size, and distribution of CCpn within the visual cortex. The visual cortex was selected specifically due to the many vision-related deficits noted in fetal alcohol exposed children and because the critical role of the CC in visual cortex development is well documented. Sprague-Dawley rat pups received one of four alcohol dosages during gestational days (G) 1-20, or reared as nutritional or untreated control animals. Each litter was categorized according to the peak blood alcohol concentration experienced. Pups were removed from each litter on days equivalent to G29, G36, G43, and G50, for histology and measurement. Callosal axons were labeled retrogradely to their CCpn using 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) and the CCpn were then examined using confocal laser scanning microscopy. Differences between alcohol-exposed and control animals were observed in CCpn cell body size, number, and location with the cortex. This was particularly true of animals exposed to high doses of alcohol. In addition, some trends of CCpn development were found to be unchanged as a result of prenatal alcohol exposure. The results demonstrate clear differences in the development of CCpn in the visual cortex between alcohol-exposed and control animals and suggest that this development is particularly affected in those animals exposed to high doses of alcohol.     

LRH-A对人胎盘和妊娠大鼠脑垂体-卵巢-子宫及胎盘作用的研究

本文研究大剂量LRH-A对人早孕胎盘绒毛、大鼠的脑垂体、卵巢、子宫和胎盘的作用。实验结果表明,大剂量LRH-A可使妊娠大鼠子宫内膜、胎盘淤血坏死,胚胎发育停滞,黄体退变及局灶性坏死,黄体细胞3β-HSD酶活性显著减弱,但大鼠垂体促性腺激素细胞超微结构没有受到明显影响。LRH-A可促进体外培养人绒毛hCG的分泌,并损害绒毛上皮的组织结构。     

A brief history of brain iron research

We present a patient with transient global amnesia (TGA) whose diffusion-weighted imaging (DWI) study showed a high-intensity signal in the left retrosplenium of the corpus callosum. In previous studies, lesions in the retrosplenium caused permanent but not transient global amnesia, called retrosplenial amnesia, by involving the thalamocortical portion of the Papez' circuit. This is the first report indicating that TGA can be associated with acute infarction only in the left retrosplenium of the corpus callosum.     

Cortical and subcortical contributions to the representation of temporal information

Converging evidence suggests that temporal representations of brief durations are derived subcortically. We tested split-brain patient JW in order to investigate whether these representations project bilaterally or unilaterally to cortex. Using visual stimuli to signal time intervals, JW was asked to compare the duration of a pair of standard stimuli that were presented bilaterally with a comparison stimulus that was presented to either the left or right visual field. Assuming the hand of response is controlled by the contralateral cerebral hemisphere, a hand by visual field interaction was predicted if the representation of stimulus duration was restricted to the cerebral hemisphere receiving the lateralized stimulus. However, we failed to observe this interaction for two different ranges of stimulus durations, both in the hundred (Experiment 2) to hundreds (Experiment 1) of milliseconds range. Instead, there was a consistent right hemisphere advantage in task performance. When the task then required a discrimination based on the physical size of the stimuli rather than their duration, an interaction between response hand and visual field was obtained (Experiment 3). Taken together, these results suggest that (1) even though the comparison stimulus was presented unilaterally, the representation of its duration was available to both cerebral hemispheres, and (2) a right hemisphere advantage in psychophysical tasks requiring the comparison of successive stimuli is observed for temporal and non-temporal judgments.     

伴颅内疾患语前聋病人的人工耳蜗植入术(附3例报告)

目的探讨伴有颅内疾患的聋儿人工耳蜗植入术候选者的手术和术前评估的问题.方法总结在我院发现的3例伴有颅内疾病的语前聋病人,3例都已经实施了人工耳蜗植入术.结果3例病人均在术前的磁共振检查发现了合并有颅内疾病,手术后病人均成功重建了听力.结论对于伴有颅内疾病的人工耳蜗植入术候选者在经过术前全面评估和审慎观察后可以实施手术;术前磁共振检查是发现大脑疾病的重要手段.     

Reduced interhemispheric inhibition in musicians

In vivo magnetic resonance imaging has revealed that the anterior half of the corpus callosum is larger in musicians trained intensively from an early age than in untrained subjects. The corpus callosum is crucial for the coordination of bimanual motor activity, but neurophysiological correlates of morphological differences in the corpus callosum of musicians are not known. In the present study we have used transcranial magnetic stimulation (TMS) to assess interhemispheric inhibition in six adult professional musicians who began musical training at an early age. Conditioning TMS was applied to the hand area of the motor cortex of one hemisphere, followed 4-16 ms later by a test stimulus applied to the other hemisphere. Tests were performed at rest, and with the first dorsal interosseous muscle contralateral to the conditioning hemisphere voluntarily active. Conditioning TMS in musicians was 29% less effective at reducing the size of the test MEP at rest, and 63% less effective in the active condition, compared with control subjects. We conclude that transcallosal interhemispheric inhibitory circuits activated by TMS are less effective in musicians than in controls.     

胎儿胼胝体发育的超声监测

目的:探讨胎儿胼胝体生长发育规律。方法:对622例孕16～39周胎儿进行胼胝体超声检查,测量胼胝体前后径,并分析其与孕周的关系。结果:胎儿胼胝体前后径与孕周呈正相关(r=0.932,P<0.001),回归方程为:胼胝体前后径(mm)=-9.567+1.495×胎龄(周)。结论:胼胝体随孕周发育的变化规律及其正常测量数据为进一步判断病变提供了参照标准。     

Amiloride Relaxes Rat Corpus Cavernosum Relaxation In Vitro and Increases Intracavernous Pressure In Vivo

Introduction

The antihypertensive effects of thiazide diuretics such as hydrochlorothiazide are commonly associated with erectile dysfunction. The association of hydrochlorothiazide/amiloride is not associated with erectile dysfunction. The hypothesis is that amiloride has beneficial effect in penile erection and, therefore, counterbalances the hydrochlorothiazide-induced disruptive effect.

Diagnostic value of Omniview technique on the agenesis of corpus callosum

Objective: This study aimed to discuss the diagnostic value of Omniview technique on the agenesis of corpus callosum.

Methods: A total of 43 pregnant women with no obvious structural abnormality and eight pregnant women who diagnosed with agenesis of corpus callosum (ACC) were included in this study. The 2D ultrasonography and the 3D ultrasonography Omniview technique were used to carry out ultrasonic examination on 43 normal fetuses and eight fetuses with agenesis of corpus callosum (as verified through magnetic resonance), respectively.

Results: The Omniview technique visually displayed the median sagittal plane of the fetus. The ROC curve of Omniview (0.999) was much higher than that of 2D ultrasonography (0.817). Rating of ACC and normal fetuses showed that the diagnostic efficiency of 3D ultrasonography Omniview technique was much higher than 2D ultrasonography.

Conclusion: 3D ultrasonography Omniview technique has certain advantage in the diagnosis of agenesis of corpus callosum, and is of great significance in the prenatal screening of callosum.     

川芎嗪对离体兔阴茎海绵体平滑肌条收缩的影响

目的 初步探讨川芎嗪(Ligustrazine)对离体兔阴茎海绵体平滑肌条的舒张作用及其机制。方法 离体家兔阴茎海绵体平滑肌实验方法,观察川芎嗪对阴茎海绵体平滑肌的舒张效应,测定去氧肾上腺素(PE)和氯化钾(Ka)的浓度-效应曲线。结果 川芎嗪浓度依赖性地舒张PE诱发的阴茎海绵体平滑肌收缩作用,最大舒张效应为(74.1±6.2)％[对照组为(21.9±5.6)％,P<0.01]。不同浓度的川芎嗪可使PE和KCL的浓度-效应曲线右移,最大收缩反应降低,高浓度(0.8g/L)时抑制收缩作用更显著。结论 川芎嗪有明显的舒张阴茎海绵体平滑肌作用,并呈剂量依赖性。川芎嗪舒张阴茎海绵体平滑肌机制可能与抑制细胞外钙内流有关。