电刺激大鼠尾核头部对丘脑后核中内脏痛反应神经元电活动的影响

电刺激同侧尾核头部(HCN)能抑制多数内脏痛兴奋神经元和内脏痛抑制神经元的电活动,使其自发放电减少或消失、内脏痛刺激引起的增频或减频效应减弱或消失。电刺激对侧的HCN也能抑制PO核中多数内脏痛反应神经元的活动,其抑制作用与同侧比较无明显差异。     

肾血管性高血压大鼠尾壳核NPY阳性神经元的变化

目的 :研究易卒中型肾血管性高血压大鼠尾壳核 NPY阳性神经元的变化。方法 :雄性 SD大鼠 6 0只 ,随机分为两组 (n=30 )。手术组用单肾单夹法复制高血压模型 ,假手术组手术过程同手术组 ,但不上银夹。于术后 7d,30 d,90 d处死动物 ,取脑 ,用 ABC免疫组化方法对大鼠尾壳核 NPY阳性神经元进行定量分析。结果 :假手术组尾壳核 NPY阳性神经元密度随年龄增加而减少 ,而手术组 NPY阳性神经元密度先减少 ,再增加 ,后保持不变。手术组和假手术组 NPY神经元密度相比 ,早期两组间无显著差异 ;中期手术组小于假手术组 (P<0 .0 5 ) ;晚期 ,手术组大于假手术组 (P<0 .0 5 )。结论 :NPY阳性神经元在高血压的发生、发展过程中起一定调控作用。     

基于MR图像的人脑尾状核定量分析方法研究

大脑结构的研究对于脑相关疾病及脑功能研究具有重要意义,随着计算机视觉和数学领域相关知识的引入,研究热点集中到感兴趣区的形状建模及形状量化分析上。尾状核作为人脑中的重要结构,对大脑活动,特别是认知方面,起着至关重要的作用。本文对MR图像进行分割,并对尾状核的绝对体积以及归一化体积进行了定量测量与分析。同时通过细化算法给出尾状核的骨架模型,得到了初步的尾状核形状描述,并应用移动立方体算法对尾状核进行三维重建,得到了较理想的尾状核可视化结果。     

大鼠帕金森综合征模型脑的黑质、尾状核及中缝核的超微结构变化

目的　观察大鼠帕金森综合症模型脑的黑质、尾状核及中缝核神经元超微结构变化。方法　应用透射电镜。结果　上述核团神经元的超微结构均发生病理性改变 :神经细胞核膜皱缩 ,核膜凹凸不整 ,并有局部断裂 ;线粒体变性 ,基质浓度降低及空泡化 ;粗面内质网和高尔基复合体囊腔扩张变性 ;大量初级溶酶体及脂褐素集聚 ;出现了髓样体和多泡体等变性结构。结论　黑质、尾状核及中缝核神经元超微结构的病理性变化从而导致纹状体 黑质 纹状体锥体外路系环路功能障碍 ,是引发帕金森氏综合症的结构基础。     

Postvibration Changes in the Spike Activity of Neurons in the Medial Vestibular Nucleus

Changes in the baseline spike activity in the medial vestibular nucleus were studied after exposure to vibration for 5, 10, and 15 days. Studies addressed the distributions of neurons within this structure in terms of the regularity of their spike activity, the dynamics of neural flows, and the modalities of interspike histogram modalities. Mean values were calculated for the major statistical measures of baseline spike activity. Statistically significant changes in the major characteristics of neuron activity were seen in the medial vestibular nucleus at different periods of vibration exposure. Vibration was found to induce complex dynamic rearrangements in the baseline activity of neurons in this structure. The characteristics and functional significance of the results are discussed.     

Activity of Neurons in the Pedunculopontine Nucleus during a Food-Related Operant Conditioned Reflex

The activity of 91 neurons in the compact and diffuse zones of the pedunculopontine nucleus of freely mobile rabbits was studied during performance of a food-related operant conditioned reflex. A total of 37.4% of the neurons recorded showed reactivity to the conditioned stimulus, which is evidence that the pedunculopontine nucleus is involved in operant learning. A significant predominance of excitatory responses to the conditioned stimulus and to food reinforcement was demonstrated. The main patterns of cell responses were identified, these reflecting the nature of the effect of the conditioned stimulus on neuron activity, the structure of the behavioral act, and the properties of the reinforcement, and demonstrating a relationship between the pedunculopontine nucleus and the processes of attention, motor learning, and reinforcement. Differences were seen in the associative reactive properties of the compact and diffuse zones of the pedunculopontine nucleus to the conditioned stimulus and reinforcement, which is evidence for the functional diversity of this formation and suggests a leading role for the cholinergic compact zone in food-related operant learning and reinforcement, the diffuse zone having a leading role in food-related classical conditioned-reflex learning.     

Early Afferent Reactions in Caudate Nucleus and Neocortex during Consolidation and Extinction of Conditioned

Experiments in cats revealed a clear-cut dependence of the early complex (up to 100 msec) of evoked potentials recorded in the caudate nucleus and temporal cortex on biological relevance of the stimulus (presence or absence of alimentary signal), with constant physical parameters. The early complex of evoked potentials can reflect activity of the mechanisms preventing non-specific motor response to exteroceptive stimulus, although it does not exclude processing the stimulus-carried information during generation of evoked potentials.     

脑室注射γ—氨基丁酸对大鼠尾核痛反应神经元放电的影响

本文在32只大鼠上,用玻璃微电极引导神经元放电,观察了脑室注射γ-氨基丁酸(GABA)后,尾核痛反应神经元电活动的规律和印防已毒素(picrotoxin,PIX)对GABA的阻断效应。研究所见:当脑内GABA含量增加时,尾核痛兴奋神经元(pain excitation neurons,PEN)电活动受到抑制,表现为痛诱发放电频率下降,潜伏期延长;痛抑制神经元(pain inhibition neurons,PIN)电活动加强,表现为抑制时程缩短,痛诱发放电频率增加。PIX可阻断这种效应。综上表明,GABA通过同时影响尾核PEN和PIN的电活动而产生镇痛效应。     

Effects of Lesioning of the Medial Cervical Nucleus on the Baseline Spike Activity of Neurons in the Central and Basolateral Nuclei of the Amygdala

Studies of the characteristics of baseline spike activity in the central and basolateral nuclei of the amygdala demonstrated significant differences between these nuclei. Lesioning of the medial cervical nucleus, which is one of the sources of ascending serotoninergic projections of the forebrain, led to marked and generally reciprocal changes in the spike activity of the amygdalar nuclei studied. It is suggested that serotoninergic afferentation from the medial cervical nucleus modulates the activity of amygdalar nuclei with different functional assignments. __________ Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 54, No. 5, pp. 698–704, September–October, 2004.     

Activity of Neurons in the Basal Magnocellular Nucleus During Performance of an Operant Task

Spike activity was studied in 95 neurons in the basal magnocellular nucleus in rabbits during spontaneous behavior and during performance of a conditioned operant response. Nearly half the neurons (48.4%) showed significant (p < 0.05) negative correlations between spontaneous discharges and the power of the frontal lobe EEG delta rhythm; most of these cells could be identified as cholinergic projection neurons. Neurons of this group had predominantly excitatory responses to the conditioned stimulus during performance of the operant task, while the responses to the conditioned stimulus of presumptively non-cholinergic neurons, not projecting to the cortex, were mainly inhibitory. The activatory responses of neurons in the basal magnocellular nucleus to the conditioned stimulus were markedly stronger while the animals performed the operant response as compared with performances in which there was no response to the conditioned stimulus. These results provide evidence that the basal magnocellular nucleus supports the level of waking and attending required for performance of operant conditioned reflex activity.     

Relationship between Bioelectric Activity of Neurons in the Gigantocellular Nucleus of the Medulla Oblongata and Spontaneous Movements of Chick Embryo

Electrophysiological study revealed a correlation between changes in bioelectric activity of the reticular gigantocellular nucleus and movements of chick embryos during ontogeny (16-20 days). This relationship increased by the end of embryogenesis. The reticular gigantocellular nucleus is the major source of supraspinal influences on motor activity during ontogeny. Blockade of proprioceptive impulses with myorelaxin inhibited bioelectric activity of the regulatory gigantocellular nucleus, which attests to the activating effect of proprioception.     

Involvement of the Rat Caudate Nucleus in the Immunostimulatory Effect of Dago

The involvement of the caudate nucleus, i.e., the terminal zone of the nigrostriatal dopaminergic system, in neuroimmunostimulation during the activation of opioid receptors by the highly specific agonist DAGO. Single doses of DAGO (100 g/kg) in sham-operated control Wistar rats induced significant increases in the numbers of direct IgM-antibody-forming and total rosette-forming cells at the peak of the immune response after immunization with sheet red blood cells. The experiments showed that bilateral electrolytic lesioning of the caudate nucleus in rats suppressed the immune response, demonstrating its involvement in neuroimmunomodulation. Since the effect of immunostimulation induced by DAGO disappeared when given to animals with caudate nucleus lesions, it was concluded that this structure is involved in activatory immunogenesis via opioid mechanisms.     

Characteristics of Small Neurons of the Reticular Thalamic Nucleus in WAG/Rij Rats

The aim of the present work was to study the ultrastructure of small neurons in the reticular thalamic nucleus (RTN) in WAG/Rij rats, which are used as a model of absence epilepsy. A total of 24 rats were studied. The brains of 10 rats were used for studies of the cytoarchitectonics and cytological characteristics of neurons, for which paraffin sections were stained with cresyl violet by the Nissl method. Electron microscopic studies were performed by microscope-controlled harvesting of the RTN with fixation in 2.5% glutaraldehyde in phosphate buffer pH 7.4. Small neurons were found to account for 5–8% of all neurons in the RTN. These had oval bodies, sparse and pale-staining cytoplasm, and were frequently located in pairs. The ultrastructure of these neurons was characterized by poor development of cell membranes, branching of the axon close to the cell body, and multiple axon contacts with the body and dendrites. It is suggested that these neurons are short-axon neurons __________ Translated from Morfologiya, Vol. 127, No. 1, pp. 56–57, January–February, 2005. Director Professor L. B. Kalimullina     

Effects of Electrical Stimulation of the Posterior Part of the Hypothalamus on the Spike Activity of Neurons in the Oral Nucleus of the Pons

Chronic experiments were performed on four cats to study evoked spike activity in neurons in the oral nucleus of the pons to electrical stimulation of the posterior hypothalamus in the waking, slow-wave sleep, and paradoxical sleep states. A total of 42% of study neurons were found to respond to stimulation during waking. PS-on and PS-off neurons were identified in the oral nucleus of the pons, along with phasic cells showing bursts of activity during the physical manifestations of paradoxical sleep. Stimulation induced inhibitory responses in PS-on neurons, excitatory responses in PS-off neurons, and excitatory and inhibitory responses in 68% and 32% respectively of phasic neurons. The magnitudes of evoked responses in these neurons changed during the sleep-waking cycle. These data demonstrate the involvement of the posterior hypothalamus in controlling the mechanisms of paradoxical sleep, these mechanisms being located in the oral nucleus of the pons.__________Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 90, No. 9, pp. 1094–1102, September, 2004.     

Ultrastructural Changes of Caudate Nucleus in Mice Chronically Treated with Manganese

Manganese (Mn) is able to cross the blood–brain barrier and induces functional and structural alterations during the intoxication by this metal. Therefore, the effects of chronic administration of Mn in the caudate nucleus of mice were evaluated by electron microscopy. Male albino mice were injected intraperitoneally with MnCl₂ (5?mg/kg/d) 5?d per week during 9 weeks. The control group received only 0.9% of NaCl solution. The caudate nuclei were extracted and subsequently processed to be observed on a conventional transmission electron microscope at 2, 4, 6, and 9 weeks after treatment. A high percentage of vacuolated and swollen mitochondria were found throughout all the analyzed periods. Myelin disarrangement and ultrastructural alterations related to edema were observed increased in Mn-treated mice at week 9. Granular degeneration of myelin at week 9 accompanied with deposition of electron dense granules in the neuropil was also observed. Edema in neuropil and glial cells was detected from week 2 to week 9 accompanied by swollen mitochondria. Neuronal bodies, synaptic terminals, and perivascular cells were found swollen. Decreased electron density in postsynaptic areas and decreased and dispersed synaptic vesicles in presynaptic areas were noted in Mn-treated animals. Some neurons from Mn-treated mice showed cisternae dilation of the Golgi apparatus. These results suggest that Mn-treatment produces structural alterations in the caudate nucleus that could be responsible for some of the neurotoxic effects of this metal.     

加压素在自发性高血压大鼠与正常大鼠下丘脑视上核、室旁核神经元内表达

目的观察加压素(AVP)在自发性高血压大鼠(SHR)与正常大鼠下丘脑视上核(SON)、室旁核(PVN)内的分布。方法应用光镜和免疫细胞化学技术。结果SHR的AVP阳性细胞内分泌颗粒密集呈棕黄色,正常大鼠组则染色较浅。SHR大鼠SON内AVP阳性神经元百分数(69.30±18.10%)明显多于正常大鼠(59.53±16.97%,P<0.05),而两组大鼠PVN内AVP的表达无明显差异。结论AVP在下丘脑的血压调节活动中起着重要的介导作用,中枢AVP含量的异常增加可能与高血压的发病有关。     

The Role of the Septal Nuclei in Controlling the Activity of Vagosensitive Neurons in the Solitary Tract Nucleus in Cats

Studies on cats anesthetized with a mixture of Nembutal and chloralose were performed to study the descending influences of single, paired, and frequent stimulation of the lateral septal nucleus (LSN) and bed nucleus of the stria terminalis (BNST) on the activity of viscerosensory neurons in the solitary tract nucleus, identified by stimulation of the cervical part of the vagus nerve. Of 70 units recorded in the solitary tract nucleus, 50 were identified as primary and secondary input vagus neurons. Single stimuli applied to the septal nuclei induced initial excitation in 30% (15 units) of vagus neurons. The latent period of these responses was 5-25 msec. Presentation of paired stimuli showed that loss of the ability to respond to the second stimulus occurred at interstimulus intervals of 10-200 and sometimes 300 msec. A total of 34% (17 units) of solitary tract nucleus neurons showed tonic changes in spontaneous activity in response to rhythmic stimulation. Increasing the stimulation frequency to 10-20 Hz led to very different changes in the spontaneous rhythm, i.e., wave-like changes (decreases and increases in frequency, secondary suppression) or complete inhibition, sometimes lasting up to 10 sec after stimulation ended. A small number of units (five) showed a blocking effect of septal discharges on the visceral afferent input in conditions of paired stimulation. These results lead to the conclusion that the LSN and BNST are involved in modulating the activity of bulbar viscerosensory neurons, though their influences are mediated mainly via oligo- and polysynaptic pathways via other limbic structures (hypothalamus, amygdala).     

Baseline Spike Activity of Neurons in the Locus Coeruleus of the Rat after Lesions to a Number of Medulla Oblongata Nuclei

Bilateral lesioning of the presublingual nucleus (nucleus praepositus hypoglossi) of the medulla oblongata induced significant changes in the nature of baseline spine activity in the locus coeruleus. After lesioning, the mean frequency of spike activity of locus coeruleus neurons decreased more than two-fold. The numbers of neurons with train-grouped activity and polymodal neurons increased significantly. Exclusion of the solitary tract nucleus led to an increase in the number of neurons with regular activity and some decrease in the mean discharge frequency in locus coeruleus neurons. These data support the suggestion that the presublingual nucleus plays a significant role in the transmission of afferent influences on the activity of locus coeruleus neurons.     

催产素对大鼠尾核痛反应神经元放电的影响

实验用Ｗｉｓｔｅｒ大鼠４８只，在尿酯（１．０ｇ／ｋｇ）麻醉下行常规手术，人工呼吸条件下进行实验。用玻璃微电极引导尾核中痛反应神经元（ＰＥＮ、ＰＩＮ）的放电，研究外源、内源催产素（ＯＴ）对其放电的影响。结果：１．尾核内微量注射ＯＴ（０．００５Ｕ／２μ可明显抑制ＰＥＮ放电频率，延长放电潜伏期．可缩短ＰＩＮ放电抑制时时程、增加放电频率。以上放电变化高峰出现在注药后６ｍｉｎ，注药后１５ｍｉｎ恢复，２．电刺     

大鼠下丘脑室旁核内一氧化氮合酶神经元的生后发育

应用 NADPH-黄递酶组织化学和一氧化氮合酶 (NOS)免疫组织化学方法以及计算机图像分析 ,观察 NOS神经元在大鼠下丘脑室旁核 (PVN)生后发育各阶段的形态及分布特征。结果显示 ,1d时 PVN内已有 NOS神经元。随着生长发育 ,PVN的面积逐渐变化 ,NOS神经元主要集中在 PVN的外侧大细胞部及腹侧部 ,细胞逐渐增多 ,胞体的平均截面积逐渐变大 ,平均灰度值逐渐降低。14d以后至成年鼠 (90 d)以上变化不明显。结果提示 ,PVN中 NOS神经元的生后发育和成熟主要在 14d前 ,尤以 7d至 14d为关键时期