大鼠小脑皮质NPY能神经元的形态与分布

目的　研究大鼠小脑皮质内NPY免疫阳性神经元的形态与分布。方法　SD大鼠 10只 ,雌雄不限 ,升主动脉灌注固定 ,开颅取小脑 ,SP免疫组织化学染色。结果　大鼠小脑内NPY免疫阳性神经元分布在皮质的Purkinje细胞层 ,胞体呈梨形或烧瓶状 ,细胞核清晰不染 ,轴突伸向颗粒层 ,树突呈网状伸向分子层 ,突起未见染色。分子层和颗粒层未见阳性细胞 ,但可见神经纤维的存在。结论　小脑Purkinje细胞层内存在NYP阳性神经元。     

选择性破坏胰腺A细胞的模型大鼠大脑皮层神经毡突触的电镜观察

目的　探讨选择性破坏胰腺A细胞的模型大鼠胆碱能神经元的变化。方法　选用硝酸钴和利血平选择性破坏大鼠胰腺A细胞后电镜观察大脑皮层神经毡胆碱能神经元突触的变化。结果　硝酸钴组模型大鼠脑突触内含胆碱能神经递质乙酰胆碱的清亮小泡比对照组明显减少 (P <0 .0 1) ,利血平组清亮小泡比对照组明显增多 (P <0 .0 5 )。结论　这种内源性乙酰胆碱的变化可能与胰腺A细胞损伤有关 ,提示胆碱能神经除受其上级中枢调节外 ,还受某些内分泌细胞的影响     

神经节苷脂GM1对新生大鼠缺氧缺血性脑病的作用研究

目的 探讨单唾液酸四己糖神经节苷脂（GM1）对新生大鼠缺氧缺血性脑病（HIE）及其后的癫痫发作是否具有保护和预防作用以及可能作用机理，为临床应用GM1治疗HIE提供理论依据。方法 建立新生大鼠HIE模型。用组织化学方法和免疫组织化学方法观察缺氧缺血后脑损害的形态学改变，兴奋性氨基酸Glu阳性（Glu-IR)神经元和抑制性氨基酸GABA阳性（GABA-IR）神经元表达和GM1对上述变化的影响。结果 盐水处理组与GM1治疗组相比病变较重，Glu-IR神经元和GABA-IR神经元数目减少与GMI治疗组差异有显著性意义。结论 GM1能够在一定程度上减轻新生大鼠缺氧拭岂血后病损灶，保护Glu-IR神经元和GABA-IR神经元，尤其是对GABA-IR神经元的保护作用，提示GM1对新生大鼠缺氧缺血后的癫痫发作具有一定的预防作用。但尚需进一步探讨研究。     

Organization of receptive fields of tonic and phasic neurons of the pulvinar in the cat

The receptive fields (RF) of 163 neurons of the pulvinar were investigated by the method of point testing the RF surface with a stationary, flashing light spot. The RFs of 26% of the neurons were characterized by a phasic pattern of response in all regions studied, while the RFs of 15% of the neurons consisted of only tonic elements. A complex RF organization, consisting of tonic and phasic subfields, was characteristic of 59% of the neurons. On the basis of this fact the postulate is advanced concerning the convergence of two types of afferents on a single pulvinar neuron. The cell population receiving inputs from purely tonic or purely phasic afferents comprises 41% of all cells investigated. The measurement of the latent periods of neuron responses to a stationary, flashing light spot showed that neurons with a phasic type of response are distinguished by a shorter latent period compared to neurons with tonic and mixed types of responses.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 69, No. 1, pp. 19–25, January, 1983.     

Brunner's gland metaplasia of residual jejunum developed long after wide resection of the small intestine

We report a rare case in which mucous glands, similar to pyloric or Brunner's glands, developed in the residual jejunum (46 cm in length) long after wide resection of the small intestine. The mucous glands were observed in the mucosal and submucosal layers near the duodenum, and the mucin showed a positive reaction by paradoxical concanavalin A staining and immunoreactivity for HIK-1083, which were histochemically the same as those in the pyloric/Brunner's glands. This type of metaplasia in the small intestine without ulceration has not been described in the literature so far. It was speculated that these glands developed as a defense response or adaptation against relatively excessive acid due to the short small intestine.     

Deoxyribonucleic acid turnover in immature neurons of the rat cerebral cortex

To test for metabolic deoxyribonucleic acid (DNA) turnover in differentiating neurons, [methyl-3H]thymidine was injected into the lateral cerebral ventricles of newly born rats, and after 6, 24 and 96 h, neuronal nuclei were prepared from the immature cerebral cortex. Enzymatic treatment converted virtually all of the DNA into soluble deoxynucleosides which were fractionated by high-performance liquid chromatography for determination of specific activity. The specific activity of thymidine was found to decline rapidly with time. The rate of this loss correlated with the radioactivity initially incorporated into the DNA. This suggested that DNA was being replaced by DNA repair as a consequence of radiation damage, rather than by spontaneous metabolic DNA turnover.     

Correction of lipid composition of the lymph and blood during immediate type hypersensitivity

The survival of neurons is a key condition for complete posttraumatic regeneration of the peripheral nerve. In experiments on rats we studied survival capacity of different neuronal subpopulations in L_IV-L_V dorsal root ganglia after ligation or transection and suturing of the sciatic nerve. Experiments with nerve ligation showed that IB4⁺ neurons are more sensitive to the injury than NF200⁺ neurons. By day 90 after ligation of the sciatic nerve IB4⁺ neurons were virtually not detected in the dorsal root ganglia. By day 90 after nerve transection the number of surviving NF200⁺ and IB4⁺ neurons decreased by 26.1 and 21.4%, respectively, in comparison with intact animals. Treatment with xymedon, a regeneration stimulator, led to a 48.5% increase in the number of surviving NF200⁺ neurons by day 30 after ligation of the nerve and a 50.7% increase by day 90. The number of surviving IB4⁺ neurons increased more than 8-fold by this term after ligation of the nerve and drug stimulation. Xymedon had a neuroprotective effect towards both neuron subpopulations, more intensely preventing apoptosis of IB4⁺ neurons.     

Spinal neuronal inhibition and EEG synchrony by electrical stimulation in subcortical forebrain regions of the cat

Summary In cats anaesthetized with sodium pentobarbital and 70% N₂O, single lumbar dorsal horn neurons were excited by controlled noxious radiant heating of glabrous hindpaw skin. The EEG was recorded from the pericruciate cortex and posterior lateral gyrus. Subcortical forebrain sites where electrical stimulation inhibited dorsal horn neuronal heat-evoked responses contralaterally were identified by mapping the caudate nucleus, internal capsule, septum, nucleus accumbens and basal forebrain regions. Inhibitory sites were mainly located in the ventral forebrain (ventral septum, diagonal band, basal forebrain). The caudate nucleus and internal capsule had a low incidence and effectiveness of inhibitory sites. In the basal forebrain, the incidence and effectiveness of inhibitory sites decreased from caudal to rostral regions. There was a rostral limit of inhibitory sites, both medially and laterally. The magnitude of inhibition increased with graded increases in brain stimulation intensity. The mean incremental increase in inhibition was greater for caudal than for rostral basal forebrain sites. Mean stimulus currents for threshold of inhibition and for inhibition to 50% of control heat responses were lower for caudal than for rostral sites. Responses of the dorsal horn neurons to increasing temperatures of noxious skin heating were monotonic linear functions over the temperature range studied (48–53° C). Stimulation in both rostral and caudal basal forebrain decreased the slope of this stimulus-response function, with a greater decrease for caudal sites. Cortical EEG synchronization was evoked by stimulation in the caudate nucleus and rostral basal forebrain. For both regions, most synchronogenic sites did not produce descending inhibition of dorsal horn neurons. The significance of these findings in relation to descending inhibition from other brain regions and stimulation-produced analgesia is discussed.     

培养大鼠皮层神经元NMDA受体蛋白单分子原子力显微镜定位研究

为在纳米尺度对 NMDA受体蛋白分子进行神经细胞膜表面原位定位和探讨原子力显微镜在生物单分子操纵和调控中的应用 ,本研究应用原子力显微镜分别对分布在云母表面的膜 NMDA受体蛋白分子标记物抗 NMDAR1Ig G-葡萄球菌蛋白 A-胶体金复合物分子和结合标记物分子后的神经元膜进行扫描 ,三维形貌测定 ,通过颗粒度分析结果 ,明确标记物分子的特征性三维形貌 ,对比确定经过免疫胶体金结合后的 NMDA受体蛋白单分子在神经元膜表面的定位。结果显示 ,空白云母表面标记物分子为分散均匀的平均粒径为 49nm的球形颗粒 ,在神经元膜表面结合 NMDA目的受体蛋白分子后 ,免疫复合物分子呈现出粒径为 5 3 nm的散在分布球形或短棒状颗粒 ,长径约为宽径的 2倍 ,长轴截面可见典型的双峰三维结构。上述结果表明 ,NMDA受体蛋白单分子可以结合 1个或 1个以上的胶体金标记物分子 ;原子力显微镜可以在纳米尺度对神经元膜 NMDA受体蛋白进行标记和其免疫复合物的三维形貌测定。胶体金颗粒标记 ,原子力显微镜测定是免疫细胞化学新方法。     

Subfornical organ and hypothalamic paraventricular nucleus connections with median preoptic nucleus neurons: an electrophysiological study in the rat

Summary The role of pathways from the subfornical organ (SFO) to the hypothalamic paraventricular nucleus (PVN) through the median preoptic nucleus (MnPO) in regulating the activity of putative vasopressin (VP)-secreting neurons in the PVN was examined in urethane-anesthetized male rats. The activity of the majority (79%) of SFO neurons antidromically identified as projecting to the MnPO was excited by microiontophoretically (MIPh) applied angiotensin II (ANG II) and the effect was blocked by MIPh-applied saralasin (Sar), an ANG II antagonist. Identified SFO neurons that were excited by MIPh-applied ANG II were also excited by intravenously administered ANG II. Electrical stimulation of the SFO produced orthodromic excitation (48%) or inhibition (24%) of the activity of MnPO neurons antidromically identified as projecting to the PVN. Identified MnPO neurons that were excited by SFO stimulation were also excited by MIPh-applied ANG II, while the remaining neurons were not affected. The excitatory responses to SFO stimulation and to MIPh-applied ANG II were both blocked by MIPh-applied Sar, whereas the inhibitory responses to SFO stimulation were not affected. ANG II injected into the region of the SFO produced either an excitation (55%) or no effect (45%) on the activity of identified MnPO neurons. Electrical stimulation of the MnPO produced orthodromic excitation (27%) or inhibition (23%) of the activity of putative VP-secreting PVN neurons. ANG II injected into the region of the MnPO produced either an excitation (31%) or no effect (69%) on the activity of putative VP-secreting PVN neurons. These observations reveal some possible interconnections between three brain regions and suggest that circulating ANG II excites a population of neurons projecting from the SFO to the MnPO, and that these neurons themselves release ANG II as an excitatory transmitter on part of MnPO neurons projecting to the PVN, thereby causing enhanced activity of putative VP-secreting PVN neurons.