Postsynaptic fibers reaching the dorsal column nuclei in the rat

Postsynaptic fibers reaching the dorsal column nuclei were investigated in rat by means of retrograde transport of wheat germ agglutinin-horseradish peroxidase conjugate. Each nucleus received only ipsilateral afferents with most of the labeled cells forming a band which covered the mediolateral extent of the dorsal horn in an area that resembled lamina IV in the cat. The labeling excluded the reticular extension of the neck of the dorsal horn. Lumbosacral afferents were restricted to the gracilis nucleus and cervicothoracic afferents to the cuneatus nucleus. Cervical and anterior lumbar levels showed additional projections coming from their most medial parts. The organization of this second-order pathway in rat is similar to that in cat and monkey.     

脑立体定向手术戒毒对近期神经心理功能的影响

目的：了解脑立体定向手术戒毒对病人智力、记忆等脑功能的影响。方法：采用韦氏成人智力量表（WAIS）、韦氏记忆测验（WMS）、HR—B神经心理成套测验（HR—B）于术前、术后对病人进行检查。结果：①WAIS：知识、相识性、图画填充等分测验以及语言智商、操作智商、总智商术后均有所提高，其中知识、图画填充及总智商有显著性意义（P〈0．05）。②WMS：倒数数字、图片回忆、联想学习、背数等分测验较手术前下降（P〈0．01），触摸测验及记忆商数（MQ）也有下降（P〈0．05）。术后5-6个月对其中19例患者的WMS测验成绩追踪，各分测验成绩及MQ均有改善，尤以数数和记忆商数改善明显（P〈0．01）。③HR—B：脑损伤指数（DQ）手术前后未见明显变化，仅分测验连线A、连线B成绩术后有降低（P〈0．01）．而利手敲击成绩较术前有提高（P〈0．01）。结论：于术戒毒未造成患者智力明显下降及脑功能障碍．近期记忆下降可在4～5个月内恢复。     

基于几何活动轮廓的神经元干细胞序列图像的自动分割

一个快速稳定的分割系统是研究神经元干细胞变化的基础，为完善此系统，针对多连接边缘模糊的细胞分割提取问题，根据曲线进化原理，我们提出了一种基于水平集方法的改进的几何活动轮廓算法。此算法能自动解决图像的拓扑变化，并能获得更加真实的细胞轮廓边缘。将此方法应用于神经元干细胞的序列图像分割，实验结果证明了此算法的有效性与准确性。     

The dorsal spino-olivocerebellar system in the cat

Summary The spino-olivocerebellar paths ascending through the dorsal funiculi (DF-SOCPs) were studied by recording climbing fiber field potentials in the cerebellar cortex. Several DF-SOCPs were identified on the basis of their response latencies, peripheral inputs, and projection areas. The projection areas consist of eight sagittal zones on each side of the anterior lobe denoted a, x, b, C₁, c₂, c₃, d₁, and d₂. The a and b zones, which are activated exclusively from hindlimb nerves (Oscarsson, 1969a) were not studied.The shortest response latencies in the x, c₁, c₃ and d₂ zones indicate that these zones are activated by direct paths between the dorsal funiculus nuclei and the inferior olive. These zones also have long latency responses evoked through indirect paths. The direct paths are activated from the flexor reflex afferents and the indirect paths from distal cutaneous afferents. The x zone is activated from forelimb nerves only. The c₁ and c₃ zones and presumably also the d₂ zone are activated from hindlimb and forelimb nerves and have a detailed somatotopical organization.The c₂ and d₁ zones have long latency responses evoked through indirect paths. Both zones are activated from distal cutaneous afferents. The c₂ zone has no distinct somatotopical organization, whereas the d₁ zone has largely separate forelimb and hindlimb areas. In contrast to all other zones, the c₂ zone is activated not only from ipsilateral but also from contralateral nerves.     

音猬因子的功能受体斑片在培养神经干细胞中的表达

目的　观察在培养的神经干细胞内是否有发育调控分子———音猬因子 (sonichedgehog)功能受体———斑片 (patched)表达。　方法　神经干细胞克隆在体外培养传代后 ,用patched的特异性引物对培养的神经干细胞进行RT PCR分析 ,PCR产物经克隆测序后 ,用地高辛标记克隆的探针 ,对神经干细胞进行原位杂交分析。　结果　神经干细胞克隆内大量的细胞均可表达sonichedgehog的功能受体patched ,patched阳性细胞间未见明显差别 ,克隆边缘与中央的patched分布也未见明显差别。　结论　sonichedgehog信号传导路可能在神经干细胞的增殖与分化过程中起重要作用。     

Associated changes in Ca2+ and Sr2+ activation properties and fiber proteins in cross-reinnervated rabbit soleus

Changes in the Ca²⁺ and Sr²⁺ activation properties of functionally skinned slow-twitch soleus fibers were measured and compared with those of normal fast-twitch extensor digitorum longus (EDL) following cross-reinnervation of soleus with the nerve to EDL. Most of the fibers showed either complete transformation of activation properties (66%) or remained unchanged (34%). The change in sensitivity to divalent cations was correlated with changes in the proteins present in fibers pooled on the basis of their activation properties. The banding patterns of the 35,000- and 37,500-dalton proteins (tropomyosin and troponin T) in cross-reinnervated soleus were correspondingly transformed to those of normal EDL. Slow and fast myosin light chains were present in the pooled cross-reinnervated fibers. Fiber distributions based on activation properties were confirmed by histochemical features. For the first time it has been demonstrated that cross-reinnervation produced changes in the activation properties of soleus fibers and associated changes in the regulatory proteins measured.     

Lipid metabolism during exercise I: Physiological and biochemical characterization of normal healthy male subjects in relation to their physical fitness

Summary On the basis of maximal oxygen uptake ( O₂ max) 18 normal, healthy men were divided into two groups of equal size: moderately trained subjects (MTR) each having O₂ max below 65.0 ml·min^–1·kg^–1 body weight (54.0±8.3) and well trained subjects (WTR), whose O₂ max exceeded 65.0 ml·min^–1·kg^–1 body weight (69.2±4.1). The WTR group had slightly (non significant, n.s.) higher percentage of slow twitch, oxidative (SO) fibers in M. vastus lateralis and higher (n.s.) activities of cytochrome c oxidase (CytOx), succinate dehydrogenase (SDH), 3-hydroxyacyl-CoA-dehydrogenase (HADH), and citrate synthase (CS), while lactate dehydrogenase (LDH) activity was lower (n.s.). In the MTR group only, the SO-%, and the activities of CytOx, SDH and HADH correlated positively with O₂ max, and LDH negatively with O₂ max. These correlations were not significant in the WTR group possibly because of the adaptations produced by training in this group. Multiple regression analysis was used to elucidate the best combination of variables to explain the variance in O₂ max. The best model consisted of the sum of relative activities of oxidative muscle enzymes (CytOx, SDH, HADH, CS), muscle LDH activity, body fat content (% F) and lean body mass. This model explained 69% of the variance in O₂ max; and of the individual variables % F was of utmost importance.     

Perceptual Speed and IQ Are Associated Through Common Genetic Factors

Individual differences in inspection time explain about 20% of IQ test variance. To determine whether the association between inspection time and IQ is mediated by common genes or by a common environmental factor, inspection time and IQ were assessed in an extended twin design. Data from 688 participants from 271 families were collected as part of a large ongoing project on the genetics of adult brain function and cognition. The sample consisted of a young adult cohort (mean age 26.2 years) and an older adult cohort (mean age 50.4 years). IQ was assessed with the Dutch version of the WAIS-3R. Inspection time was measured in the so-called -paradigm, in which a subject is asked to decide which leg of the -figure is longest at varying display times of the -figure. The number of correct inspections per second (i.e., the reciprocal of inspection time) was used to index perceptual speed. For Verbal IQ and Performance IQ, heritabilities were 85% and 69%, respectively. For perceptual speed, 46% of the total variance was explained by genetic variance. No differences in heritability estimates across age cohorts or sexes were found. Across the whole sample, a significant phenotypic correlation was found between perceptual speed and Verbal IQ (0.19) and between perceptual speed and Performance IQ (0.27). These correlations were entirely due to a common genetic factor that accounted for 10% of the genetic variance in verbal IQ and for 22% of the genetic variance in performance IQ. This factor is hypothesized to reflect the influence of genetic factors that determine axonal myelination in the central nervous system.     

一种EEG信号盲分离和分类的神经网络方法

提出一种采用多神经网络处理脑电(EEG)信号的方法。首先，对混有噪声的脑电信号给出一种盲分离的自适应神经算法。通过寻求采样时间序列线性组合的kurtosis系数的局部极值，得出该算法的模型和步骤。在盲分离的基础上，对分离出的估计信号进一步利用Kohonen网络进行分类。将该算法用于300个EEG样本处理，并给出处理结果。     

Chronic morphine treatment increases the expression of the neural cell adhesion molecule in the dorsal horn of the mouse spinal cord

It is well known that prolonged exposure to morphine results in tolerance to morphine-induced antinociception. In the present study, we found that mice that were tolerant to morphine-induced antinociception exhibited an increase in immunoreactivity for the neural cell adhesion molecule in the dorsal horn of the spinal cord, which was highly overlapped with immunoreactivity for the increased metabotropic glutamate receptor 5 induced by morphine. These findings support the idea that repeated stimulation of μ-opioid receptors increases the expression of neural cell adhesion molecule and metabotropic glutamate receptor 5. This phenomenon leads to the enhanced excitatory synaptic transmission in the dorsal horn of the spinal cord, and in turn suppresses the morphine-induced antinociception.