Constructing the rodent stereotaxic brain atlas:a survey

The stereotaxic brain atlas is a fundamental reference tool commonly used in the field of neuroscience.Here we provide a brief history of brain atlas development and clarify three key conceptual elements of stereotaxic brain atlasing:brain image,atlas,and stereotaxis.We also refine four technical indices for evaluating the construction of atlases:the quality of staining and labeling,the granularity of delineation,spatial resolution,and the precision of spatial location and orientation.Additionally,we discuss state-of-the-art technologies and their trends in the fields of image acquisition,stereotaxic coordinate construction,image processing,anatomical structure recognition,and publishing:the procedures of brain atlas illustration.We believe that the use of single-cell resolution and micron-level location precision will become a future trend in the study of the stereotaxic brain atlas,which will greatly benefit the development of neuroscience.

Development of Digital Stereotaxic Instrument for Pigeons(Columba Livia)

Stereotaxic instrument is an indispensable tool for numerous types of neuroscience studies and is routinely performed in neuroscience laboratories as part of a variety of experimental procedures.Due to the development of robotics and automation,the stereotaxic instrument for rodents has made great progress,while it is relatively backward and scarce for birds.A digital stereotaxic instrument for pigeons(Columba livia),a classic animal model for learning,memory and cognition,was developed in this study.Its performance was verified from three aspects including stereotaxic accuracy,stereotaxic stability and stereotaxic reproducibility.The developed stereotaxic instrument has the following characteristics:(1)a digital positioning system was used,which is characterized by high stereotaxic accuracy;(2)a novel head-fixation system was developed to increase the adaptability of head-fixation;(3)a four-point fixation method was suggested,improving the stability of head-fixation;(4)the stereotaxic instrument has strong versatility,which can be suitable for a wide variety of birds.Moreover,the proposed stereotaxic instrument has better positioning accuracy and stability,which will promote the study of neural mechanisms for pigeons.

Cre-recombinase systems for induction of neuronspecific knockout models:a guide for biomedical researchers

Gene deletion has been a valuable tool for unraveling the mysteries of molecular biology.Early approaches included gene trapping and gene targetting to disrupt or delete a gene randomly or at a specific location,respectively.Using these technologies in mouse embryos led to the generation of mouse knocko ut models and many scientific discoveries.The efficacy and specificity of these approaches have significantly increased with the advent of new technology such as cluste red regula rly inters paced short palindromic repeats for targetted gene deletion.However,several limitations including unwanted off-target gene deletion have hindered their widespread use in the field.Crerecombinase technology has provided additional capacity for cell-specific gene deletion.In this review,we provide a summary of currently available literature on the application of this system for targetted deletion of neuronal genes.This article has been constructed to provide some background info rmation for the new trainees on the mechanism and to provide necessary information for the design,and application of the Cre-recombinase system thro ugh reviewing the most f requent promoters that are currently available for genetic manipulation of neuro ns.We additionally will provide a summary of the latest technological developments that can be used for targeting neurons.This may also serve as a general guide for the selection of appropriate models for biomedical research.

Lipopolysaccharide mouse models for Parkinson's disease research:a critical appraisal

Parkinson's disease,the most common movement disorder,has a strong neuroinflammatory aspect.This is evident by increased pro-inflammatory cytokines in the serum,and the presence of activated microglial cells,and inflammatory cytokines in the substantia nigra of post-mortem brains as well as cerebrospinal fluid of Parkinson's disease patients.The central and peripheral neuroinflammatory aspects of Parkinson's disease can be investigated in vivo via administration of the inflammagen lipopolysaccharide,a component of the cell wall of gram-negative bacteria.In this mini-review,we will critically evaluate different routes of lipopolysaccharide administration(including intranasal systemic and ste reotasic),their relevance to clinical Parkinson's disease as well as the recent findings in lipopolysaccharide mouse models.We will also share our own expe riences with systemic and intrastriatal lipopolysaccharide models in C57BL/6 mice and will discuss the usefulness of lipopolysaccharide mouse models for future research in the field.

立体定向治疗颅内疾病115例疗效观察

目的：探讨主体定向技术的临床应用及治疗脑深部病变的疗效。方法：利用ASA—602S和Fischer脑立体定向仪治疗115例脑深部病变患者，其中血肿排空治疗54例，定向活检治疗17例，脑脓肿抽吸术9例，囊性颅咽管瘤置入Ommaya管2例，帕金森病行丘脑腹外侧核射频温控热凝毁损术30例，颅内异物摘除3例。结果：脑内血肿治愈50例，好转3例；活检确诊为胶质瘤9例，生殖细胞瘤2例，肺癌脑转移4例，脑寄生虫1例，三脑室后部病变活检为松果体瘤1例；5例胶质瘤行手术治疗后病情好转；其余肿瘤行放射治疗有4例痊愈(2例生殖细胞瘤，2例转移性肿瘤)；9例脑脓肿经抽吸抗炎治疗后均痊愈；2例颅咽管瘤置放Ommaya管后(行囊内放疗)痊愈好转各1例；30例帕金森病行丘脑腹外侧核射频温按热凝毁损术，痊愈29例，好转1例。3例颅内异物经主体定向摘除术均痊念。结论：主体定向临床应用广泛，治疗脑深部病变定位精确，损伤小，操作简便，安全可靠，值得推广。

Analysis of Therapeutic Effect of X-knife on Intracranial Tumors in 44 Cases

Objective to investigate therapeutic methods and effect of X－knife for on intracranial diseases. Method Recent effect of 44 pqtients with cranial diseases by X－knife was observed. Radiological follow－up was performed on 40 cases with mean 5.65 months of follow－up time. Result 92.5％of tumors were controlled locally, stability and recovery rate was 90.0％.The local control of metastatic tumors of brain was higher,but most patients with metastatic tumors died of primary lesion.New metastatic lesions appeared in patients without panencephalic radiotherapy in 1～5months .Tumors of pineal region were sensitive to X－knife.Conclusion X－knife has a definite effect on intracranial diseases .For patients with tumors of pineal region complicated by serious hydrocephalus,shunting should be conducted before X－knife treatment.For patients with mild or morderate hydrocephalus,X－knife chould be utilized only under correct interventions such as dehydration.The local control rate of intracranial metastatic tumors was high,but survival time postoperation depended on panencephalic radiotherapy or control of primafry lision. For tumors with diameter >3cm,pituitary tumors,brains stem tumors and tumors in cerebellopontine angle region repeated X －knife were suggested,which could improve cure rate and decrease complications.

影像导航在鼻内镜外科中的应用

随着鼻内镜外科技术的不断提高,鼻内镜手术范围也不断扩大。但受解剖变异、病变侵及范围、前期手术史、操作方法与技巧等多种因素的影响,鼻内镜手术的疗效及安全性在一些复杂病例中仍是一个严峻的挑战。随着计算机技术和神经影像学的发展，1986年Roberts等首先报道利用声波数字化仪将CT扫描资料和手术显微镜结合，

A newly developed open-end intracranial hematoma drainage tube

Objective: To design a new open-end intracranial hematoma drainage tube for clinical application. Methods: The newly developed device consists of two parts: the plunger and barrel.On one side, the barrel is bullet shaped with an opening tip. The plunger is located in the middle cavity of the tube barrel and extended out at the open-end. It was designed for strengthening the tube barrel and for convenience in performing the drainage procedure. It can be used by inserting the drainage tube into the lesion and pulling out the plunger, whereby blood will forcefully rise up inside the barrel, providing a satisfactory outcome. It is made for effusion drainage purposes. During the procedure, the drainage tip is placed at the deepest part of the intracranial hematoma to completely drain the blood. Moreover, the plunger fits tightly in the tube, preventing leakage during the operation. With the use of the device, brain can be separated. In addition, the device can help reduce the risk of cerebral damage because of the small operating area. The barrel sidewall has matching opening holes bilaterally and equally for exchanging substances between the inner and outer parts.The overlapping ratio in each horizontal pair is around 1/3–1/2. Each pair on the opposite side will form a different pressure. Thus, the opening holes will not easily get blocked with blood clot. Results: Blood and accumulated liquid from the deepest part of the intracranial hematoma can be directly drawn through the drainage tube without damaging a large area. The tube does not get blocked easily and allows for complete removal of the hematoma. Conclusions: The device is asuitable instrument for clinical application.

N-terminally truncated Aβ4-x proteoforms and their relevance for Alzheimer’s pathophysiology

Background:The molecular heterogeneity of Alzheimer’s amyloid-β(Aβ)deposits extends well beyond the clas-sic Aβ1-40/Aβ1-42 dichotomy,substantially expanded by multiple post-translational modifications that increase the proteome diversity.Numerous truncated fragments consistently populate the brain Aβpeptidome,and their homeo-static regulation and potential contribution to disease pathogenesis are largely unknown.Aβ4-x peptides have been reported as major components of plaque cores and the limited studies available indicate their relative abundance in Alzheimer’s disease(AD).Methods:Immunohistochemistry was used to assess the topographic distribution of Aβ4-x species in well-char-acterized AD cases using custom-generated monoclonal antibody 18H6-specific for Aβ4-x species and blind for full-length Aβ1-40/Aβ1-42-in conjunction with thioflavin-S and antibodies recognizing Aβx-40 and Aβx-42 proteo-forms.Circular dichroism,thioflavin-T binding,and electron microscopy evaluated the biophysical and aggregation/oligomerization properties of full-length and truncated synthetic homologues,whereas stereotaxic intracerebral injections of monomeric and oligomeric radiolabeled homologues in wild-type mice were used to evaluate their brain clearance characteristics.Results:All types of amyloid deposits contained the probed Aβepitopes,albeit expressed in different proportions.Aβ4-x species showed preferential localization within thioflavin-S-positive cerebral amyloid angiopathy and cored plaques,strongly suggesting poor clearance characteristics and consistent with the reduced solubility and enhanced oligomerization of their synthetic homologues.In vivo clearance studies demonstrated a fast brain efflux of N-termi-nally truncated and full-length monomeric forms whereas their oligomeric counterparts-particularly of Aβ4-40 and Aβ4-42-consistently exhibited enhanced brain retention.Conclusions:The persistence of aggregation-prone Aβ4-x proteoforms likely contributes to the process of amyloid formation,self-perpetuating the amyloidogenic loop and exacerbating amyloid-mediated pathogenic pathways.