Discriminative conditioning-related slow potential and single-unit responses in the frontal cortex of urethane-anesthetized rats

A model is described for obtaining long-term and stable discriminative conditioning-related slow-potential and single-unit responses from the frontal cortex of urethane-anesthetized rats. Responses were recorded and analyzed to reinforced (rewarding medial forebrain bundle stimulation) and non-reinforced tone cues. In the present study, cortical event-related slow potentials provided an adequate index of the level of discriminative conditioning. Single-unit response patterns are described for 57 neurons which demonstrated a discriminative response to either the reinforced or non-reinforced tone cue.     

兔内听动脉阻断与听觉改变的关系

目的 探讨实验性内听动脉阻断与术后听力改变的关系及术中听觉监控的方法。方法 实验兔乙状窦后进路暴露小脑桥脑角，下压小脑暴露内听道及第Ⅷ神经复合体，分辨出内听动脉，予阻断不同时间，分别行蜗神经直接复合动作电位(DCAP)和畸变产物耳声发射记录(DPOAE)。结果对照组DCAPN1波潜伏期值无明显改变。内耳血供阻断10s和30s组在压迫开始后3min，DCAPN1波潜伏期值均恢复为初始值。内耳血供阻断1min组在压迫开始后3h，DCAPN1波潜伏期值未恢复为初始值假手术组DPOAE幅值无明显改变，内耳血供阻断10s、30s对DPOAE幅值无影响，内耳血供阻断1min使得DPOAE幅值下降结论兔内耳血供阻断1min可能造成兔听觉不可逆损伤。DCAP、DPOAE能有效、持续地监控内耳血供阻断，是耳神经外科手术中实用的听觉监测手段。     

Regulation of single potassium channels by serotonin in the cell bodies of the tail mechanosensory neurons ofAplysia californica

Sensory neurons in the pleural ganglion ofAplysia mediate the afferent portion of the tail withdrawal reflex. Previous work has shown that in these neurons and in the siphon sensory neurons ofAplysia, serotonin modulates a steady-state non-inactivating potassium current called the S current. Using the technique of patch clamping, we have examined the kinetics of single potassium channels and found that they share the properties of the S potassium channel of the siphon sensory neurons. This channel has an elementary slope conductance of73 ± 9.98pS(x±S.E.M.) and shows Goldman rectification. It is active at the resting potential and does not inactivate with maintained depolarization. Bath application of serotonin in a majority of experiments decreased the functional number of channels in the patch.     

3种钾通道在哮喘豚鼠气道高反应中的作用

目的：探讨钙激活钾通道（KCa）、延迟整流型钾通道（Kdr）和ATP敏感型钾通道（KATP）在哮喘豚鼠气道高反应中的作用。 方法： 采用离体气管环张力实验，观察加入特异性钾通道阻断剂后，与不加阻断剂相比气管环对组胺反应的量效曲线的差异。 结果： （１）加入KCa阻断剂TEA后，对照组气管环对组胺的反应变化不显著，而哮喘组气管环对10-4mol/L、10-3mol/L组胺的收缩反应均显著低于不加TEA的气管环(P<0.01)，量效曲线明显下移；（2）加入Kdr阻断剂4-AP后，对照组气管环对10-3mol/L组胺的最大收缩反应明显下降(P<0.05)，组胺的量效曲线下移，哮喘组气管环对10-4mol/L、10-3mol/L组胺的收缩反应均低于不加4-AP的气管环(P<0.01)，且下降程度较对照组大（P<0.05），量效曲线明显下移；（3）加入KATP阻断剂glibenclamide后，对照组和哮喘组气管环对组胺的量效曲线与不加glibenclamide的气管环相比变化均无明显差异。 结论： 在豚鼠哮喘模型中，KCa和Kdr活性的降低在气道高反应的发生中起介导作用，KATP作用不明显。     

Reassessment of the accuracy of traditional sperm characteristics and adenosine triphosphate (ATP) in estimating the fertilizing potential of human semen in vivo

Receiver operating characteristic curves and accuracy parameters were computed for traditional sperm characteristics (concentration, motility, morphology) and the number of peroxidase negative cells, and the concentration of adenosine triphosphate (ATP) in semen from populations of fertile and infertile men, and men who achieved a pregnancy after varicocele treatment. The percentage and concentration per millilitre of spermatozoa with rapid linear progressive motility, and the ATP concentration, provided the best discrimination between fertile and treated fertile from infertile men. The misclassification rate was higher for sperm morphology, total progressive motility and viability, whereas sperm concentration and the total sperm count per ejaculate had the worst discriminating power. The number of peroxidase negative cells per 100 spermatozoa was highly specific in identifying men who achieved pregnancy after varicocele treatment. The lower limit of normality of sperm characteristics was remarkably different between fertile men and men achieving pregnancy after treatment or during infertility work-up.     

脑瘫患儿脑干听觉诱发电位研究

本文采用日本光电公司生产的 MEB-5304K 诱发电位测定仪,对101名6月-14岁脑瘫患儿和40名正常儿测定了脑干听觉诱发电位(BAEP)。结果表明:给予80dBNHL,20Hz 刺激时 BAEP 异常率为45.54%,随刺激强度减小及刺激重复率增加,BAEP 阳性率提高。BAEP 改变与病情、病型及并发症有关。为脑瘫的发病机理及病理生理学研究提供神经电生理学依据。对脑瘫合并听力障碍者有助于及早选用助听装置,解决其听力障碍问题。     

用视诱发电位和富里叶变换作视力客观估计

目的:研究用图形视觉诱发电位(PVEP)和离散富里叶变换(DFT)作视力客观估计的方法。方法:检测对象为33只正常眼。用翻转频率为10次/秒,条纹张角分别为30、20、18、12、10、6、4和2弧分的垂直方波光栅图形刺激,记录相应的稳态图形视诱发电位。用离散富里叶交换提取WEP频谱中10Hz成分的幅值。以光栅条纹张角为横坐标、相应的VEP频谱幅值为纵坐标作关系曲线,取阈值附近的近似线性部分的数据点作直线回归,用外推法求得阈值和视力。结果:比较VEP所测之视力与用国际标准视力表所测之视力,可见在本研究中70％的受检眼VEP视力估计较准确。结论:用本研究中的VEP技术客观地测量视力可靠性较高。眼科学报1997;13:59～61。     

Analysis of reflex activity in cardiac sympathetic nerve induced by myelinated phrenic nerve afferents

Electrical stimulation of the phrenic nerve afferents evoked excitatory responses in the right inferior cardiac sympathetic nerve in chloralose-anaesthetized cats. The reflex was recorded in intact and spinal cats. The latency and threshold of the volley recorded from the phrenic nerve as well as of the cord dorsum potentials evoked by electrical stimulation of the phrenic nerve indicated that group III afferents were responsible for this reflex. The phrenicocardiac sympathetic reflex recorded in intact cats was followed by a silent period. The maximum amplitude of the reflex discharges was 800 microV, the latency was 83 ms and the central transmission time 53 ms. Duration of the silent period lasted up to 0.83 s. In spinal cats the reflex was recorded 5.5-8 h after spinalization. The maximum amplitude of the spinal reflex discharges ranged from 22 to 91 microV and the latency from 36 to 66 ms.