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Employing cyto‐, myelo‐, and chemoarchitectural staining techniques, we analyzed the structure of the hippocampal formation in the banded mongoose and domestic ferret, species belonging to the two carnivoran superfamilies, which have had independent evolutionary trajectories for the past 55 million years. Our observations indicate that, despite the time since sharing a last common ancestor, these species show extensive similarities. The four major portions of the hippocampal formation (cornu Ammonis, dentate gyrus, subicular complex, and entorhinal cortex) were readily observed, contained the same internal subdivisions, and maintained the topological relationships of these subdivisions that could be considered typically mammalian. In addition, adult hippocampal neurogenesis was observed in both species, occurring at a rate similar to that observed in other mammals. Despite the overall similarities, several differences to each other, and to other mammalian species, were observed. We could not find evidence for the presence of the CA2 and CA4 fields of the cornu Ammonis region. In the banded mongoose the dentate gyrus appears to be comprised of up to seven lamina, through the sublamination of the molecular and granule cell layers, which is not observed in the domestic ferret. In addition, numerous subtle variations in chemoarchitecture between the two species were observed. These differences may contribute to an overall variation in the functionality of the hippocampal formation between the species, and in comparison to other mammalian species. These similarities and variations are important to understanding to what extent phylogenetic affinities and constraints affect potential adaptive evolutionary plasticity of the hippocampal formation.  相似文献   
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角类动物药质量控制模式与方法的创新和发展   总被引:1,自引:0,他引:1  
通过述评角类动物药质量控制模式与方法 的现状,针对角类动物药本身的特点进行分析,探索从生物鉴定的角度建立角类动物药质量控制模式和方法 的可行性,并提出基于外观鉴别-物性鉴定-化学组分分析-生物效价检测序贯分析的角类动物药质量控制模式,为从根本上解决长期制约角类动物药发展的瓶颈问题,创建一套有效的内在质量控制方法 提供新的理论依据与技术支撑.  相似文献   
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目的:观察电针对大鼠脊髓背角NOS的影响,探讨局部与夹脊不同部位电针治疗神经病理性疼痛的机制是否存在差异。方法:采用坐骨神经钳夹大鼠模型,将30只雄性SD大鼠随机分为正常对照组(A组)、模型组(B组)、节段电针组(C组,取双侧L4“夹脊”穴)、局部电针组(D组,取双侧“阳陵泉”)。通过NADPH—d组织化学染色,观察电针后脊髓背角NOS表达的变化。结果:模型组比正常组、电针组脊髓背角NOS的表达均增多(P〈0.05)。节段电针组脊髓背角NOS的表达较局部电针组减弱(P〈0.05)。结论:电针的镇痛作用可能部分是通过抑制NOS的活性实现的。与局部电针组相比,节段电针组抑制NOS活性的作用较强。  相似文献   
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Most spiking neurons are divided into functional compartments: a dendritic input region, a soma, a site of action potential initiation, an axon trunk and its collaterals for propagation of action potentials, and distal arborizations and terminals carrying the output synapses. The axon trunk and lower order branches are probably the most neglected and are often assumed to do nothing more than faithfully conducting action potentials. Nevertheless, there are numerous reports of complex membrane properties in non-synaptic axonal regions, owing to the presence of a multitude of different ion channels. Many different types of sodium and potassium channels have been described in axons, as well as calcium transients and hyperpolarization-activated inward currents. The complex time- and voltage-dependence resulting from the properties of ion channels can lead to activity-dependent changes in spike shape and resting potential, affecting the temporal fidelity of spike conduction. Neural coding can be altered by activity-dependent changes in conduction velocity, spike failures, and ectopic spike initiation. This is true under normal physiological conditions, and relevant for a number of neuropathies that lead to abnormal excitability. In addition, a growing number of studies show that the axon trunk can express receptors to glutamate, GABA, acetylcholine or biogenic amines, changing the relative contribution of some channels to axonal excitability and therefore rendering the contribution of this compartment to neural coding conditional on the presence of neuromodulators. Long-term regulatory processes, both during development and in the context of activity-dependent plasticity may also affect axonal properties to an underappreciated extent.  相似文献   
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为了降低盐酸林可霉素粗品中的B组分含量,采用萃取与结晶相结合的方法,分别研究了萃取结晶过程中萃取剂种类、用量、原料浓度、溶液pH等条件以及溶析结晶过程中的混合速率对产品纯度的影响。结果表明:丁醇或氯仿有较高的萃取效率;降低原料浓度或在萃取、反萃时分别保持溶液pH为11和5均有利于提高产品中的A组分含量;结晶过程中提高搅拌速率有利于提高产品纯度。以氯仿为萃取剂,经过单级萃取,结晶后产品中A组分纯度最高可达97.86%。  相似文献   
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The hippocampal formation plays a critical role in cognitive function. The developmental events that shape the hippocampal formation are continuing to be elucidated and their implications for brain function are emerging as well as applying those advances to interventions that have important possibilities for the treatment of brain dysfunction. The story told in this chapter is about the use of the in oculo transplant method to illuminate intrinsic and extrinsic features that underlie the development of the dentate gyrus and adjacent hippocampus and the role of one molecule in the hippocampus and schizophrenia. Schizophrenia, originally conceptualized as a dysfunction in dopaminergic neurotransmission, is now known to involve multiple neuronal systems. Dysfunction of hippocampal neurons is emerging as one of its signature pathological features. Basic insights into the development and function of hippocampal interneurons form the basis of a new treatment initiative for this illness. Evidence for the role of the alpha 7-nicotinic acetylcholine receptor in the development and function of these neurons in rodents has led to human trials of nicotinic agonists for cognitive dysfunction in schizophrenia and the possibility of improving hippocampal development in children at risk for schizophrenia by perinatal supplementation with choline, which can act as an alpha 7-nicotinic acetylcholine receptor agonist.  相似文献   
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Elderly patients may experience impairments in cognition or mood following surgery. To study the development and underlying mechanisms of these postoperative behavioral changes, young (3 months) and aged (18–20 months) male rats were subjected to abdominal surgery followed by behavioral testing during a period of 6 weeks. Microglia activation (IBA-1) and neurogenesis (DCX) were immunohistochemically determined. In separate experiments, the effects of anesthesia and the cytokine response (IL-6) following surgery were evaluated.  相似文献   
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Uen YH  Chen TH  Shyu JF  Shyr YM  Su CH  Chen JY  Lee CS  Liu JC 《Surgery today》2006,36(4):312-315
PURPOSE: When removing the thyroid gland, great care must be taken to avoid damaging the recurrent laryngeal nerves (RLNs). The present study aims to present a clear picture of certain anatomical features of the RLNs in relation to the inferior thyroid artery (ITA), the tracheoesophageal groove (TE), Berry's ligament, and the inferior cornu of the thyroid cartilage in Chinese adults. METHODS: We removed a collective 120 RLNs from 60 Chinese adult cadavers (52 men and 8 women), and examined their anatomic course and relationship on both sides. RESULTS: The right and left RLNs were found in the tracheoesophageal groove in 78.3% and 91.3% of cases, respectively. Both RLNs were found posterior to and to the right of the ITA in 80% of cases, and one was found on the left side of the ITA in 91.7%. Most of the RLNs were within 3 mm of Berry's ligament, with a laryngeal entry point about 0.8 cm below and just anterior to the inferior horn of the thyroid cartilage. CONCLUSIONS: The inferior cornu of the thyroid cartilage is a reliable landmark in identifying the RLNs. Racial variations between Caucasians and Chinese may explain some anatomic differences.  相似文献   
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