肠道菌群与孤独症谱系障碍免疫失衡的研究进展

孤独症谱系障碍是一种神经发育障碍性疾病，主要表现为缺乏社会交流和互动能力，同时伴有重复刻板行为。近年来研究发现孤独症谱系障碍患者常可伴有胃肠功能异常，同时国内外部分研究发现孤独症谱系障碍患者肠道菌群构成与健康儿童相比发生了显著变化。但其具体机制仍不明确，甚至出现了相反的结论。该文通过回顾相关文献资料，从微生物―肠―脑轴角度出发，着重从肠道代谢产物异常、免疫失衡及神经发育角度对肠道菌群介导的免疫失衡在孤独症谱系障碍发病机制中的作用进行综述。 [国际神经病学神经外科学杂志, 2023, 50(4): 65-70]     

抑郁障碍与谷氨酸功能

抑郁障碍是一种常见的慢性精神障碍。传统对抑郁障碍病因的解释主要集中在单胺类神经递质的功能失调上。近年来，越来越多的证据表明谷氨酸在抑郁障碍的发病机制中充当着重要的作用。本文将围绕谷氨酸及其受体的功能，以及谷氨酸功能失调在抑郁障碍动物模型与临床初步研究等作一概述。     

孤独症谱系障碍患者生物运动知觉障碍与社会认知功能的关系及其神经机制的研究进展

近年来,孤独症谱系障碍(ASD)患者的生物运动知觉障碍越来越受到研究者的关注。生物运动障碍是指无法准确捕捉他人动作传递出的信息状态和意图。研究发现孤独症谱系障碍患者的生物运动知觉障碍与ASD的核心症状社会认知功能缺陷密切相关。本文对孤独症谱系障碍的生物运动知觉障碍与社会认知功能的关系及其神经机制的研究进行梳理,从ASD患者生物运动价值的敏感性不足可能会导致社会功能缺陷、低水平视运动知觉功能缺陷可能导致情绪识别能力障碍两个方面阐述,介绍了ASD生物运动知觉障碍在ASD发生和发展中的作用,并对患者生物运动知觉缺陷的神经机制的相关研究进行了总结。本综述可为深入研究ASD的生物运动知觉障碍与社会认知功能障碍的关系提供参考。     

孤独症谱系障碍兴奋性与抑制性平衡的磁共振波谱研究进展

孤独症谱系障碍(ASD)是一种可能由于遗传因素及环境因素共同作用所导致的复杂的精神障碍,其临床诊断主要基于行为学评估而缺乏神经生物学基础,为临床诊断、分型和干预治疗增加了难度。近期许多研究报道指出,大脑兴奋性与抑制性神经递质的浓度改变可能是ASD的主要发病机制。本文通过搜索近年来国外关于ASD兴奋性与抑制性神经递质的磁共振波谱研究,作一综述。目的是为日后研究ASD神经化学机制提供信息。     

运动干预在孤独症儿童中的应用进展

孤独症谱系障碍(Autism spectrum disorder,ASD)是一种常见的神经发育障碍,其核心缺陷表现在两个方面:社会交流、互动障碍和限制性、重复性行为模式.目前,孤独症谱系障碍的全球患病率逐年上升,其发病机制仍在探索中,治疗与干预方式较多,运动干预对ASD儿童起到一定作用.文章旨在就现今主流的运动干预形式,以及其对ASD儿童的疗效作用作一综述.     

孤独症谱系障碍早期遗传诊断和治疗研究进展

孤独症谱系障碍是一种严重的神经发育障碍, 童年早期起病, 主要临床特点为社会交往障碍、刻板重复行为和兴趣范围狭窄。其病因学极其复杂, 为一组多基因疾病, 是遗传因素、表观遗传因素和环境因素共同作用的结果。本文中将围绕孤独症谱系障碍遗传病因学方面的早期诊断和治疗研究进行综述。     

谷氨酸能系统障碍与卒中后抑郁

近年来,大量研究表明谷氨酸能系统障碍可能与卒中后抑郁（PSD）的发病机制密切相关。本文主要从外周血小板功能障碍、海马神经元再生及重塑障碍两方面阐述谷氨酸能系统障碍在PSD病理生理机制中发挥的作用。     

孤独症谱系障碍表观遗传机制的最新研究进展

孤独症谱系障碍(ASD)是一组复杂的神经发育障碍性疾病。虽然研究表明该疾病具有很高的遗传性, 但目前仍存在争议。相较之下, 表观遗传学可以更好地解释ASD的发病机制, 弥补了遗传学研究中的不足。本文通过分析国内外ASD表观遗传机制的相关研究, 论述表观遗传学在ASD发病机制中的作用, 以期为临床提供新的治疗思路和理论依据。     

代谢型谷氨酸受体与癫痫

兴奋性神经递质谷氨酸与谷氨酸受体结合 ,在癫痫的发病中发挥重要作用。对谷氨酸受体的研究表明 ,谷氨酸受体存在两种类型 [1 ] :离子型谷氨酸受体(intropic glutamate receptors,i Glu Rs)和代谢型谷氨酸受体 (metabotropic glu-tam ate receptors,m Glu Rs )。前者包括NMDA、     

非多巴胺能神经递质在左旋多巴诱导异动症中的作用及防治措施

非多巴胺能神经递质在左旋多巴诱导异动症中的作用仍未完全阐明,并缺乏有效的治疗方法。本文综述了谷氨酸、γ-氨基丁酸、阿片肽等非多巴胺能神经递质在异动症中的作用机制,提出应用谷氨酸受体拮抗剂、内源性大麻酯受体激动剂、5-羟色胺受体激动剂、阿片受体拮抗剂、腺苷2A受体拮抗剂、肾上腺素α受体拮抗剂等可减轻非多巴胺神经递质对异动症的影响,预防异动症的发生。     

Asymmetry in the structural organization of the ganglion layer of the retina in the frog

Silver-impregnated retinal preparations were used to study the distribution density and topographic features of small and large ganglionic cells (GC) of Rana ridibunda and Rana temporaria. For both species the increased density of GC (a streak) stretched higher than the naso-temporal axis passing through the optic disk. Beyond the streak the density of small GC was maximal in the central zone of the retina and decreased towards its periphery. For the upper quadrants of the retina the density of small GC was higher than that for the lower ones by 26% on the average. On the contrary, the density of large GC was higher in the lower part of the retina as compared to the upper one, the difference being more pronounced for R. temporaria. The density of large GC was also asymmetric with respect to the dorso-ventral axis being higher in nasal quadrants than in temporal ones by 40-55%. The highest density of large GC was found in the middle zone of the retina. The found structural asymmetry in the retinal output raster may bear an adaptively ecological meaning and may condition the particularities of the formation of the visually guided prey-catching and avoidance reactions.     

Local nonuniformities in the syncytium of the horizontal cells of the retina in the turtle

Electrical coupling between horizontal cells of the turtle retina was investigated by means of two microelectrodes (current and recording ones) penetrating neighbouring cells at a fixed distance from each other. The morphological coupling was revealed by means of fluorescent dye Lucifer Yellow. The electrical coupling was confirmed between elements of similar type (L1--axonal terminals, or L2--cell bodies, or R/G type cells) and no coupling was found between elements of different types, though L1 and L2 are directly connected through thin axons. In the L1 syncytium the electrical coupling at small (less than or equal to 50 microns) but fixed distances between microelectrodes could differ several times depending on the minimal displacement of microelectrodes. This local nonuniformity of coupling can be explained on the basis of structural nonuniformities in the L1 (axon terminal) network. It is unlikely however that the structural nonuniformities can influence the functional properties of horizontal cell network when the retina is stimulated adequately (by light).     

Early stages in the formation of the cerebellum in the frog

The formation of the cerebellum was studied during the first 6 months of the tadpole stage of the bullfrog by using standard histological methods and reconstructions from serial horizontal sections. Three major developmental phases were noted in the formation of the cerebellum. (1) During the first 5 weeks of development, the neuroepithelium proliferated and the dorsal mesencephalic plates increased in size. (2) Starting in the sixth week, a patch of neuroepithelium began to differentiate and gave rise to a small population of Purkinje cells. In subsequent weeks, the area of differentiation continued to spread and a Purkinje cell layer became established along the dorsal margin of the cerebellar plate. (3) In the 12th week, the ventrolateral part of the cerebellar plate began to increase in size and generate two populations of small cells. The lateralmost part of the neuroepithelium in this area generated a group of cells that formed an external granular layer that was one cell deep. Cells of this external granular layer migrated inward into the primitive molecular layer, and by the 26th week only a remnant of an external granular layer remained in the cerebellum. The more medially situated part of the neuroepithelium gave rise to another population of small cells that formed a column, which appeared to be continuous with the Purkinje cells, but differed from them in size. It should be noted that full maturation of the cerebellum occurs during metamorphosis, which in this species remains some 2 years away.     

Inhomogeneities in the propagation of the slow wave in the stomach

The propagation of the slow wave in the stomach and its role in inducing sweeping peristaltic contractions toward the pylorus, essential for a proper digestion and emptying, have been studied for many years. Irregularities in the timing or in the pattern of propagation of the slow wave have been known to induce various gastric malfunctions and, recently, several types of gastric dysrhythmias have been described which could lead to gastric contraction abnormalities. In this study, Du et al. have analyzed the disturbances caused by a simple transmural incision in a human stomach, performed to obtain a biopsy of the muscle, on the propagation pattern of the slow wave. In addition, they show that such an incision may by itself also induce new types of gastric dysrhythmias. These results are important in demonstrating that the function of the stomach can easily be disturbed by such procedures. This mini‐review describes several ways in which inhomogeneities in propagation may affect the conduction pattern of the slow wave, including the genesis of several dysrhythmias, and what is currently known about their impact on gastric contraction and digestion.     

Gradients of histogenesis in the ependymal lining of the third ventricle in the rabbit

Tritiated thymidine autoradiography was used to analyze the site, time of origin, and developmental gradients of the specialized lining of the ependymal surface of the third ventricle. Cells destined to form the ependyma are generated between days 15 and 22 of embryogenesis (gestation: 30 +/- 2 days), the majority of the cells undergoing final division on the 18th day of gestation. Ependymal cells originate in an orderly fashion according to 3 gradients. Two gradients of opposite direction (ventrodorsal and dorsoventral) are found in the parasaggital plane. Both gradients start at the level of the hypothalamic sulcus, progressively departing from this anatomical landmark as histogenesis progresses. A third gradient occurs in the caudorostral axis, such that cells located in caudal regions originate earlier than those located in rostral sectors. Thus, an orderly relationship exists between the time of origin of ependymal cells and their final location within the lining of the ventricular wall. These findings indicate, once again, the topographic nature of the gradients of histogenesis. The histogenic gradients displayed by the ependymal lining of the third ventricle appear strongly related to those exhibited by other diencephalic derivatives. The latter suggests that common factors govern the developmental sequence of all diencephalic derivatives as a function of their relative topographic location, independently of their functional role in the adult.     

Challenges in the Management of the HIV Patient in the Third Decade of AIDS

The epidemic of AIDS has been increasingly recognized as a major health and socioeconomic problem, not only in the United States or Africa, but also the rest of the world. The face of the epidemic has changed. The role that mental health providers play has also significantly grown as the epidemic continues on. Prior to the introduction of Highly Active Anti-Retroviral Therapy (HAART) and other advances in HIV care, the patients faced issues that related to death and dying. These advances brought with them renewed hope and resurrected lives. The patients fought with issues related to living new lives with HIV no longer an imminent death threat. In the third decade of AIDS, the struggles of the post-HAART era continue but bring with it more challenges. Mental health providers need to familiarize themselves with these issues so that they can better help HIV patients cope with this devastating disease.     

Analysis of the habituation-like changes in transmission in the temporodentate pathway of the rat

Habituation-like decrements in extracellular measures of synaptic activation (population EPSP) and cell discharge (population spike) were analyzed in the dentate gyrus of the rat following repetitive low-frequency stimulation of the medial and lateral entorhinal cortex. Stimulation of either subdivision of the entorhinal projection system resulted in comparable habituation-like response decrements with similar stimulation regimens. However, habituating stimulation of one subdivision did not result in decreased responsiveness to stimulation of the other. Repetitive low-frequency stimulation or even a single pulse delivered to either subdivision did, however, result in a potentiation of granule cell discharge in response to stimulation of the other subdivision (a form of heterosynaptic potentiation). This heterosynaptic potentiation of granule cell discharge was not accompanied by any increase in the extracellular EPSP. Comparisons of the relationship between the population EPSP and population spike before and during habituating stimulation revealed changes in cell discharge in response to the habituating stimulus which could not be accounted for by changes in synaptic activation alone. The results suggest that repetitive activation of the temporodentate pathway alters granule cell output as a result of two processes, a habituation-like decrement in synaptic activation, and a potentiation of granule cell discharge as a consequence of prior activation.