BACKGROUND & AIMS: :Hoffmann (H) reflexes from foreleg flexor nerves were studied in cats. The right and left flexor nerves were stimulated and H reflexes were recorded from the same nerves. Paw preference was assessed by a food reaching test. Stimulation of the right median nerve elicited mono- and polysynaptic reflexes from the left ulnar nerve (crossed flexor nerve). Picrotoxin depressed, and strychnine increased H reflexes from both sides without affecting the spinal motor asymmetry. H reflexes were found to be larger on the left than the right side in right-preferent cats and vice versa in left-preferent cats. The right H-reflex recovery curve was higher than left in right-preferent cats. The inhibitory period of the recovery cycle disappeared after picrotoxin and changed to facilitation for the nonpreferred side. Strychinine caused bilateral, nearly-synchronous motoneuronal discharges from the right and left flexor nerves; the discharges originating from the left side preceded those from the right side in a right-preferent cat. These results indicate that spinal motor activity predominates on the nonpreferred side, which would be a prerequisite for postural adjustments during paw use in cats. This asymmetric motor organization in the forelegs of cats having quadrpedal locomotion seems to be similar to asymmetric motor organization in legs in humans.

背景与目标： : 在猫中研究了来自前肢屈肌神经的霍夫曼 (H) 反射。刺激左右屈肌神经，并记录同一神经的H反射。通过食物到达测试评估了爪子的偏好。右正中神经的刺激引起左尺神经 (交叉屈肌神经) 的单突触和多突触反射。苦味素抑制，士的宁增加两侧的H反射，而不影响脊柱运动不对称。在右偏爱的猫中，左侧的H反射比右侧大，反之亦然。右偏好猫的右H反射恢复曲线高于左。微毒素后，恢复周期的抑制期消失，并改变为非首选侧的促进作用。马钱子碱引起左右屈肌神经的双侧，几乎同步的运动神经元放电; 在右偏爱的猫中，来自左侧的放电先于右侧的放电。这些结果表明，脊柱运动活动在非首选侧占主导地位，这将是猫在使用爪子时进行姿势调整的先决条件。具有四足运动的猫前肢中的这种不对称运动组织似乎与人类腿部中的不对称运动组织相似。

BACKGROUND & AIMS: :GABA content of isolated, dark adapted frog retina was found to be 3.15 +/- 0.28 mM. After 30 minutes of exposure to intense light (200 lx), retinal GABA levels increased about 70%. Interestingly, incubation of dark adapted retina for 30 minutes with medium containing 0.4 mM taurine also led to a 70% increase in GABA levels. Since the light-induced elevation in GABA content was reduced over 50% by a simultaneous injection of 0.02 mM strychinine, it is likely that the light-induced GABA change is partly mediated by the release of taurine from the retina seen after light exposure. However, incubation of isolated retina with medium containing increasing concentrations of taurine (1, 2 and 20 mM), caused a progressive rise in 14C-GABA efflux from retina that was preloaded with 2.2 microM GABA and exposed to dim light (0.05 lx). It was also shown that taurine (1 and 5 mM) dramatically reduced 14C-aspartate efflux from retina preloaded with radioactive aspartate and exposed to dim light conditions. By comparison, intense light stimulation (40 lx) reduced basal 14C-aspartate efflux while dark exposure increased 14C-aspartate loss from the isolated retina. We found that taurine depressed the b-wave signal of frog retina, with the maximum effect occurring at a concentration of 1 mM. Addition of strychnine (0.4 mM) reversed the taurine effect on the b-wave, indicating that taurine receptors must be present in the inner retina. By contrast, taurine (0.1-20 mM) had no effect on the P111 component of the ERG initiated by either aspartate or cobalt. However, taurine exerted a modest depressant activity on P111 initiated by glutamate. The significance of these data relative to the putative neurotransmitter function of taurine in the inner retina is discussed.

背景与目标： : 发现孤立的深色适应青蛙视网膜的GABA含量为3.15/- 0.28 mM。暴露于强光 (200 lx) 30分钟后，视网膜GABA水平增加约70%。有趣的是，黑暗适应视网膜与含有0.4 mM牛磺酸的培养基孵育30分钟也导致GABA水平的70% 增加。由于通过同时注射0.02 mM的士冬氨酸，随着50% 的推移，光诱导的GABA含量升高降低，因此光诱导的GABA变化可能部分由暴露后从视网膜中释放的牛磺酸介导。然而，将分离的视网膜与含有浓度增加的牛磺酸 (1、2和20 mM) 的培养基一起孵育，导致来自预先装有2.2 microM GABA并暴露于暗光 (0.05 lx) 的视网膜的14C-GABA流出逐渐增加。还显示，牛磺酸 (1和5毫米) 显着减少了来自预先装有放射性天冬氨酸并暴露于昏暗光线条件下的视网膜的14c-天冬氨酸外排。相比之下，强光刺激 (40 lx) 减少了基底14c-天冬氨酸的流出，而黑暗暴露增加了离体视网膜14c-天冬氨酸的损失。我们发现牛磺酸抑制了青蛙视网膜的b波信号，最大的作用发生在1毫米的浓度下。添加士的宁 (0.4 mM) 逆转了牛磺酸对b波的作用，表明牛磺酸受体必须存在于内部视网膜中。相比之下，牛磺酸 (0.1-20 mM) 对由天冬氨酸或钴引发的ERG的P111组分没有影响。然而，牛磺酸对谷氨酸引发的P111具有适度的抑制活性。讨论了这些数据相对于牛磺酸在视网膜内的假定神经递质功能的重要性。

BACKGROUND & AIMS: :The crude drug, Chotoko (Uncariae Uncis cam Ramlus), the hooks of Uncaria spp. (Rubiaceae), has been claimed to possess sedative and anti-spasmodic actions, and is contained in a Chinese traditional preparation, Choto-san, as a main crude drug. Examinations were made on the anti-convulsion effects of Choto-san and Chotoko against some animal models of epilepsy conducted by the stimulation of drugs or electricity. Oral administration of the Choto-san extract to mice at the doses of 1.0 g/kg and 3.0 g/kg tended to inhibit the glutamate-induced convulsion in a dose-dependent manner, and the effect of the Chotoko extract at a 3.0 g/kg dose was significant, while both the extracts showed no activity against the picrotoxine-induced, strychinine-induced, and electroshock convulsions. The Choto-san preparation without Chotoko was inactive, and the activity of the Chotoko extract was more potent than that of the every crude drug comprising Choto-san, suggesting that Chotoko plays the most important role in the Choto-san prescription and contains some active compounds. Bioassay-guided fractionation of the Chotoko extract led to the location of the active components in the less polar alkaloids-containing fraction, from which three indole alkaloids, geissoschizine methylether (1), hirsuteine (2) and hirsutine (3), and an oxyindole alkaloid, isocorynoxeine (4) were isolated and identified. Oral administration of 1 and 2 to mice at the doses of 50, 100, and 200 mg/kg inhibited the glutamate-induced convulsion in a dose-dependent manner. The effect of 3, the dihydro derivative of 2, was less potent than those of 1 and 2. Compound 4 showed no activity at a 100 mg/kg dose compared with control. The above results support the Chinese herbal description of the anti-spasmodic action of Chotoko, and show that 1 and 2 contained in Chotoko must be mainly contributed to the activity. It is also suggested that Choto-san may be clinically available for treatment of epilepsy.

背景与目标： : 粗药，chootoko (Uncariae Uncis cam Ramlus)，钩藤属的钩。(茜草科)，据称具有镇静和抗痉挛作用，并作为主要生药包含在中国传统制剂Choto-san中。检查了Choto-san和Chotoko对通过药物或电刺激进行的某些癫痫动物模型的抗惊厥作用。以1.0g/kg和3.0g/kg的剂量对小鼠口服Choto-san提取物倾向于以剂量依赖性方式抑制谷氨酸引起的惊厥，并且以3.0g/kg的剂量对Chotoko提取物的作用是显着的，尽管两种提取物均对苦豆碱诱导的，马冬氨酸诱导的和电击惊厥均无活性。不含Chotoko的Choto-san制剂无活性，并且Chotoko提取物的活性比包含Choto-san的每种粗制药物的活性更有效，这表明Chotoko在Choto-san处方中起着最重要的作用，并且包含一些活性化合物。生物测定指导的Chotoko提取物的分馏导致活性成分在极性较小的含生物碱部分中的位置，其中三种吲哚生物碱，geissoschizine methylether (1)，hirsuteine (2) 和hirsutine (3)，以及一种氧吲哚生物碱，分离并鉴定了异糖苷 (4)。以50、100和200 mg/kg的剂量对小鼠口服1和2以剂量依赖性方式抑制谷氨酸诱导的惊厥。2的二氢衍生物3的作用不如1和2的作用。与对照相比，化合物4在100 mg/kg剂量下无活性。以上结果支持了中草药对Chotoko的抗痉挛作用的描述，并表明Chotoko中所含的1和2必须主要有助于该活性。还建议Choto-san在临床上可用于治疗癫痫。