舟骨-大-小多角骨新型融合器的稳定性*

背景：传统的舟骨-大-小多角骨局限性腕关节融合方法包括克氏针、U形钉、AO/ASIF钢板等,术后均需长时间的石膏外固定。而美国设计的新型融合器主要应用于欧美人,并不适合于亚洲人种。 目的：模拟舟骨-大-小多角骨局限性腕关节融合,测试课题组根据中国人舟骨-大-小多角骨背侧关节凹陷的解剖形态研发出的新型融合体的稳定性。 设计、时间及地点：观察性实验,于2006-04/2007-03在南通大学骨科生物力学实验室完成。 材料：40具未经防腐处理的新鲜尸体前臂标本,X射线平片证实无腕关节病变或排列异常。 方法：所有标本均模拟舟月骨分离的腕关节不稳定模型,并行新型融合器融合,再模拟屈50°、伸35°、尺偏30°、桡偏10°各50 000次极限运动。所有标本均于运动前后行CT扫描、三维重建。 主要观察指标：测量桡舟角、桡舟间距、舟骨长度、大-小多角骨宽度及大-小多角骨倾斜角运动前后的变化。 结果：运动前桡舟角、桡舟间距、舟骨长度、大-小多角骨宽度及大-小多角骨倾斜角分别为(38.725±2.230)°,(18.988±1.216)mm,(1.686±0.191)cm,(27.360±1.571)mm,(114.975±2.293)°;运动后以上指标分别为：(38.800±2.388)°,(19.215±1.443)mm,(1.683±0.209)cm,(27.718±1.910)mm,(115.300±3.023)°。运动前后相比,所有指标的变化差异均无显著性意义(P > 0.05)。 结论：应用新型融合器行舟骨-大-小多角骨局限性腕关节融合后,舟骨-大-小多角骨融合体稳定性可靠,腕关节可在背伸35°、掌屈50°、桡偏10°、尺偏30°范围内进行早期功能锻炼。     

人工韧带支架材料选择与腕关节韧带运动损伤的修复

摘要 目的：对腕关节韧带损伤及人工韧带支架材料的选择进行探讨。 方法：电子检索PubMed数据库及CNKI数据库,在标题和摘要中以“腕关节,韧带,损伤,支架”或“wrist Joint, ligament, injury, Stent”为检索词进行检索。选择与腕关节韧带损伤和治疗手段、材料学特点、生物相容性及其应用效果相关的文献,同一领域则选择近期发表或发表在国家核心期刊杂志的文献,最终纳入18篇。 结果：人工合成可吸收性生物支架材料可作为韧带假体代替损伤的肌腱或韧带。LARS人工韧带模仿了人体韧带的解剖结构和生物力学特征,抗疲劳强度好,不易诱发炎症。自体移植肌腱韧带治疗动力型舟月骨间分离的效果较好,治疗静力型舟月骨间分离的效果差,生物型人工韧带的成品,与正常肌腱外观相似,质地柔韧,达到了预先设想的要求。 结论：良好的生物相容性和抗疲劳强度,是选择韧带肌腱支架材料的必备条件,LARS人工韧带是一种理想的移植材料,但更适合于急性韧带损伤患者。自体移植肌腱韧带的供体选择较为困难。生物型人工韧带对腕关节韧带损伤的修复取得了较好的治疗效果。细胞和分子生物学技术以及基因疗法的运用,将成为腕关节韧带损伤的治疗与康复的新方向。 关键词：腕关节;韧带;损伤;支架;康复;生物材料;组织工程 doi:10.3969/j.issn.1673-8225.2010.47.034     

国人髌骨假体设计参数的解剖学观测

目的：测量国人髌骨假体的解剖学参数。 方法：取成人干燥髌骨标本73块,左38块,右35块,测量髌骨假体骨床厚度,髌骨关节面厚度,髌骨外侧关节面宽度,髌骨内侧关节面宽度,髌骨内外侧关节面相交处长度,髌骨内外侧关节面的交角。实验结果用SPSS 10.0软件进行统计处理和分析。 结果：左右侧标本之间髌骨假体骨床厚度分别为(13.69±1.33),(13.35±1.19) mm;髌骨关节面厚度为(5.64±1.40),(5.63±1.26) mm;髌骨外侧关节面宽度为(24.54±2.27),(24.51±2.36) mm;髌骨内侧关节面宽度为(19.04±2.10),(18.54±1.81) mm;髌骨内外侧关节面相交处长度为(28.34±2.49),(27.44±2.20) mm;髌骨内外侧关节面的交角为(135.7±7.8)°,(136.5±7.6)°,各参数相比,差异均无显著性意义(P > 0.05)。 结论：实验中各参数可为国人髌骨骨床和截骨厚度的选择及髌骨假体设计参数提供参考。     

关节镜下腕横韧带切开术治疗迟发性正中神经麻痹

目的探讨关节镜下腕横韧带切开术治疗迟发性正中神经麻痹的效果。方法从2003-06我科对17例迟发性正中神经麻痹采用奥津一郎的单切口方法在关节镜下行腕横韧带切开术。入口取腕横韧带近侧2～3 cm及掌长肌腱尺侧1cm。经皮下将内窥镜从掌长肌腱和尺侧腕屈肌腱间进入。在关节镜下用钩刀切开腕横韧带。结果术后随访6～27月,平均14月。手术后6月桡侧3指半感觉恢复。无血管及神经损伤等并发症发生。结论关节镜下腕横韧带切开术运用于治疗迟发性正中神经麻痹,具有手术安全、疗效可靠、创伤小、住院时间短、有利于早期功能锻炼等优点。     

聚对苯二甲酸乙二醇酯材料LARS韧带重建兔前交叉韧带后早期组织学及超微结构变化

背景：LARS韧带由法国JP Laboureau 1985年设计并应用于临床。中短期临床应用报道证实该人工合成韧带疗效满意，但目前该韧带材料移植后组织学转归的研究较少。 目的：应用聚对苯二甲酸乙二醇酯材料LARS韧带重建兔前交叉韧带，对移植后移植物组织学及超微结构进行观察。 设计、时间及地点：随机对照动物实验，于2007-01/12在苏州大学附属第二医院实验中心及相关实验室完成。 材料：聚对苯二甲酸乙二醇酯材料LARS韧带为手术中剩余的LARS韧带残端共3条（上海科隆有限公司提供）；健康成年新西兰白兔12只。 方法：采用系统抽样法将兔分为两组，自体前交叉覆盖残端组（L-LARS）共9膝，右膝前交叉韧带完全切断后，应用体外编织的聚对苯二甲酸乙二醇酯材料LARS韧带重建，并应用前交叉韧带残端覆盖LARS韧带；单纯LARS韧带组（LARS）共3膝，前交叉韧带完全切除后单纯应用体外编织的聚对苯二甲酸乙二醇酯材料LARS韧带重建前交叉韧带。 主要观察指标：术后1，3，6个月切取关节内、骨道内移植物及关节内滑膜组织行苏木精－伊红染色及Masson染色观察，并应用透射电子显微镜观察移植物术后6个月的超微结构。 结果：术后1个月，L-LARS组关节内LARS韧带纤维束被纤维结缔组织包裹，而LARS组手术后6个月仍不能被纤维结缔组织包裹。术后3个月，L-LARS组关节内LARS韧带纤维束包裹的纤维结缔组织为不成熟的胶原纤维组织，L-LARS组和LARS组骨道内或LARS韧带纤维束之间，均存在中等程度的异物反应或炎症反应，以LARS组明显。术后6个月，L-LARS组关节内LARS韧带纤维束之间仍为不成熟的胶原纤维组织；L-LARS组及LARS组骨道内或LARS韧带纤维束之间，异物反应或炎症反应逐渐减轻；L-LARS组及LARS组骨道内均存在骨长入，新生编织骨起始于骨道壁，向人工材料的深层长入；术后6个月，电子显微镜见L-LARS组人工纤维束间胶原纤维直径50~100 nm，关节内人工纤维束间的成纤维细胞及骨道内人工纤维束间的成骨细胞体积和细胞核增大，粗面内质网扩张。 结论：聚对苯二甲酸乙二醇酯材料LARS韧带生物相容性较好；关节内游离部分用自体组织覆盖后，有助于人工韧带材料“生物化”；移植后骨道内是否存在有效骨长入仍需进一步观察。     

骶髂关节韧带应用解剖学意义

背景：骨盆后部结构中,骶髂后韧带复合体、骶结节韧带和骶棘韧带的完整,对骨盆稳定性有重要作用。 目的：观察骶髂关节周围韧带解剖结构,了解各韧带对关节稳定性的作用。 方法：对20具防腐成年尸体骨盆标本,共40侧依次采用前后方入路,对骶棘韧带,骶结节韧带,耻骨联合及骶髂关节诸韧带结构进行解剖学观察。 结果与结论：骶髂关节周围韧带可分为3组：骶髂前韧带、骶髂骨间韧带和骶髂后韧带。耻骨上下韧带及耻骨前后韧带。骶棘韧带和骶结节韧带。此3组韧带主要有两个功能：连接脊柱和骨盆环;维持骨盆环的稳定。     

人工骨材料磷酸钙及硫酸钙在腱-骨愈合中的作用

背景：有关促进腱-骨愈合的方法文献报道很多,主要方法就是给腱-骨间隙添加一些刺激物质,以此促进腱骨的愈合。磷酸钙盐作为生物活性材料具有骨传导性,已广泛应用于临床骨缺损的替代和填充。而硫酸钙作为人工材料,具有潜在的骨诱导活性。 目的：在自体腘绳肌肌腱移植重建膝关节前交叉韧带过程中,观察人工骨材料磷酸钙及硫酸钙促进腱-骨愈合的效应。 方法：选用36条雄性成熟比格犬,先行切断双侧膝关节前交叉韧带,取同侧后肢趾长屈肌腱作为移植物,采用悬吊式固定重建前交叉韧带。按随机数字表法分为3组,磷酸钙组于股骨腱骨隧道中注入磷酸钙,硫酸钙组注入硫酸钙,空白组韧带重建结束后不添加任何填充物。分别于重建后1,2,3,4,6个月取材行大体观察、组织学和生物力学观测。 结果与结论：前交叉韧带重建后1,2,3,4个月时,磷酸钙组及硫酸钙组腱骨界面纤维连接明显强于空白组,而磷酸钙组、硫酸钙组差异无显著性意义。6个月时,各组愈合程度相似。生物力学方面,重建后1个月时,磷酸钙组及硫酸钙组腱骨界面的抗拉脱强度均高于空白组(P < 0.05),而磷酸钙组、硫酸钙组差异无显著性意义(P > 0.05)。提示磷酸钙及硫酸钙均能促进腱-骨愈合,两者之间无明显差异。     

前交叉韧带切断兔外侧半月板中白细胞介素1β的表达

背景：研究证明,膝关节前交叉韧带切断后,白细胞介素1β是关节软骨退变中一个重要的调控因子,然而白细胞介素1β在外侧半月板退变中有何作用,未见文献报道。 目的：观察兔前交叉韧带切断后外侧半月板中白细胞介素1β阳性表达率的变化并探讨其意义。 方法：6月龄雄性新西兰大白兔48只,将兔膝关节配对为实验侧和对照侧造模。实验侧行前交叉韧带切断手术,制作兔前交叉韧带断裂模型;对照侧显露前交叉韧带但不行切断。造模后第1,3,6,8周,分别麻醉下随机处死兔12只。进行大体观察和外侧半月板组织学退变评分,免疫组织化学检测白细胞介素1β阳性表达率。 结果与结论：前交叉韧带切断后,随时间延长,实验侧外侧半月板组织学退变评分逐渐增高,实验侧各时间组织学退变评分显著高于对照组(P < 0.05)。各时间点实验侧白细胞介素1β阳性表达率均较对照组增高(P < 0.05);第3,6周实验侧白细胞介素1β表达阳性率高于第1,8周(P < 0.05),第8周高于第1周(P< 0.05)。结果表明,兔前交叉韧带切断后实验侧白细胞介素1β阳性表达率增高,提示白细胞介素1β参与了外侧半月板组织的退变。白细胞介素1β阳性表达率降低并不表示外侧半月板组织退变结束。     

关节镜下自体、异体骨-髌腱-骨与半腱肌腱3种重建后交叉韧带方法的比较

背景：目前重建后交叉韧带的方法很多，常涉及到不同的移植材料，但不同移植材料之间比较的研究较少见。 目的：比较分析膝关节镜下自体、异体骨-髌腱-骨与半腱肌腱3种重建后交叉韧带的疗效。 设计、时间及地点：回顾性病例分析，于2000-01/2005-09在解放军广州军区广州总医院骨科完成。 对象：选择2000-01/2005-09收治的交叉韧带损伤患者76例，其中异体骨-髌腱-骨移植27例，自体骨-髌腱-骨移植21例，自体四股半腱肌28例。 方法：回顾分析21例膝关节镜下自体骨-髌腱-骨移植、28例自体半腱肌腱移植和27例异体骨-髌腱-骨移植重建后交叉韧带的情况。采用Lysholm膝关节评分、国际膝关节文献编制委员会分级评估标准(IKDC)和KT-1000评价疗效。检测术后住院期间患者体温。 主要观察指标：①关节活动范围。②后抽屉试验及KT-1000检查关节稳定性。③Lysholm和IKDC评分检测膝关节整体功能。④不良反应。 结果：随访26~79个月。3组患者终末随访的IKDC分级、Lysholm评分、KT-1000结果和后抽屈试验阳性率之间的组间差异无显著性意义(P > 0.05)。自体骨-髌腱-骨重建组3例膝关节10°屈曲受限；同种异体骨-髌腱-骨重建组1例5°屈曲受限；半腱肌腱重建组2例屈曲受限。3组间膝关节屈曲受限比率差异无显著性意义。3组患者均无关节粘连、伤口感染、植入物断裂、螺丝钉松脱、髌骨骨折、血管神经损伤等并发症；自体骨-髌腱-骨重建组12例有不同程度的膝前痛。半腱肌腱重建组5例有不同程度的膝后痛。3组膝周痛发生率的组间差异有显著性意义(P=0)，自体骨-髌腱-骨组最高，半腱肌组次之，异体骨-髌腱-骨最低。3组术后发热时间组间比较发现，异体骨髌腱骨高于自体骨髌腱骨和自体半腱肌组(P=0)。自体骨髌腱骨与自体半腱组间的差异无显著性意义(P=0.844)。4例异体骨-髌腱-骨出现排斥反应，表现为胫骨隧道外口持续果酱样液体流出，经换药、激素或消炎痛治疗后痊愈。 结论：关节镜下自体、异体骨-髌腱-骨与半腱肌腱移植重建后交叉韧带均取得满意的结果，并且疗效相似。     

兔前交叉韧带断裂后外侧半月板的组织学退变☆

背景：前交叉韧带切断后可引起膝关节透明软骨的退变,导致骨关节炎的发生,但对外侧半月板的影响目前尚未见文献报道。 目的：观察兔前交叉韧带切断后外侧半月板组织学变化。 设计、时间及地点：同体对照观察,于2007-09/12在中南大学湘雅医学院动物学部完成。 材料：6月龄雄性新西兰大白兔48只,实验初始体质量(2.5±0.3) kg。 方法：48只大白兔双后侧膝关节按简单随机法配对分为实验侧和对照侧造模。实验侧行前交叉韧带切断手术。对照侧显露前交叉韧带但不行切断,行止血及体积分数为3%双氧水、生理盐水交替冲洗后缝合切口。选取造模后第1,3,6,8周为观测时间点,每个时间点随机处死12只。 主要观察指标：对外侧半月板进行大体观察和组织学检查。 结果：前交叉韧带切断组外侧半月板第1周即可见退变,随时间延长退变逐渐加重,对照组未见明显退变。半月板纤维软骨退变组织学评分：实验组(第1,3,6,8周)均高于对照组(P < 0.05);实验组第6,8周均高于第1,3周,差异有显著性意义(P < 0.05);实验组第1,3周差异无显著性意义(P > 0.05)。 结论：前交叉韧带断裂可引起外侧半月板退变。     

国人膝关节尺寸与5种人工膝关节假体尺寸的对照

背景：设计符合国人解剖结构的人工膝关节假体，需要大量国人解剖学研究资料。国内目前尚缺乏与股骨远端、胫骨近端截骨面和髌骨的几何学、形态学相关的数据。 目的：临床收集国人膝关节尺寸与目前国内常用（进口、合资）的5个厂家人工膝关节假体的尺寸进行对照，为设计符合国人解剖结构的人工假体提供依据。 设计、时间及地点：人工膝关节假体的尺寸与临床收集的膝关节截骨后尺寸进行对照分析，于2005-02/10在解放军总医院骨科进行。 对象：初次行人工全膝关节表面置换并在术中保留髌骨的膝关节骨性关节炎及类风湿性关节炎患者77例(105膝)，男23例(32膝)，女54例(73膝)。人工膝关节假体：LINK GEMINI MK II ，40%(42膝)；中国台湾United-U1，34.3%(36膝)；Depuy PFC，16.2%(17膝)；Zimmer NexGen-Flex，9.5%(10膝)。 方法：首先行胫骨近端截骨，采用胫骨髓内或髓外定位，后倾5°~10°截骨，游标卡尺测量胫骨平台横径、内侧平台前后径、外侧平台前后径。然后行股骨远端截骨，股骨髓内定位，假体试模测量股骨远端前后径，股骨远端均采用外翻7°，外旋3°截骨。采用电动摆锯行股骨髁下部、前部、后部、前斜面、后斜面5个方向截骨，测量股骨远端及髌骨相关参数，可在截下来的后髁骨片上测量股骨后髁长度。 主要观察指标：股骨髁前后径、股骨髁前部宽、股骨髁前斜面宽、股骨髁内外径、胫骨外侧平台前后径、胫骨内侧平台前后径、胫骨平台横径。 结果：5种膝关节股骨髁假体的前后径/内外径与国人相比存在明显差异，且比值偏大；而胫骨内侧平台前后径/胫骨平台横径和胫骨外侧平台前后径/胫骨平台横径的比率范围过于集中，胫骨内侧平台覆盖率不佳，外侧平台出现悬挂现象。 结论：5种厂家设计的膝关节假体尺寸及各参数间的比率与国人有所不同，就其总体性能来看并不完全适用于国人。     

Absence of mediolateral reorganization of dorsal horn somatotopy after peripheral deafferentation in the cat

The effect of chronic transection of the sciatic and saphenous nerves on the receptive fields of dorsal horn neurons in the L7 segment has been reinvestigated in six cats anesthetized with chloralose. Following nerve transection only a narrow lateral band of dorsal horn contained neurons with light touch receptive fields; these were situated on the proximal part of the hind limb. Dorsal horn neurons situated more than about 0.25 mm medial of the lateral edge (at the level of lamina IV) of the dorsal horn lost their light touch receptive fields, and did not acquire new light touch RFs on the proximal part of the hind limb for as long as 49 days after nerve transection. There was thus no sign of the extensive mediolateral reorganization of somatotopy described by some previous workers. Many affected neurons throughout laminae IV to VI became phasically responsive to mechanical stimulation of unidentified mechanoreceptors in deep tissue (e.g., muscle, tendon, joints, and fasciae) of the proximal part of the limb. Some of these neurons had quite low thresholds to mechanical distortion. A small proportion of neurons in medial lamina V and VI may acquire large, high-threshold cutaneous mechanoreceptive fields on the proximal part of the limb. The relation of these time-dependent changes to the known distribution of primary afferent fibers within the dorsal horn is discussed.     

Efferent connections of the lateral cortex of the lizard gekko gecko: Evidence for separate origins of medial and lateral pathways from the lateral cortex to the hypothalamus

The lateral cortex of the lizard Gekko gecko is composed of three parts: a dorsal and ventral part located rostrally and a posterior part located caudally. In order to obtain detailed information about the efferent connections of these lateral cortex subdivisions, iontophoretic injections of the anterograde tracers Phaseolus vulgaris leucoagglutinin and biotinylated dextran were made in the various parts. The main projection from the dorsal part terminates in the caudal part of the medial cortex. Other cortical projections were noted to the ipsi- and contralateral lateral cortex, the large-celled part of the medial cortex, and the dorsal cortex. Additional fibers were found bilaterally in the anterior olfactory nucleus and the external amygdaloid nucleus. The ventral part of the lateral cortex projects mainly to the ipsilateral, posterior part of the dorsal ventricular ridge and the external amygdaloid nucleus. Minor contralateral projections to these nuclei were also found. Other projections were observed to travel to the caudal part of the medial cortex, to the nucleus sphericus, and bilaterally to the lateral cortex and the anterior olfactory nucleus. The posterior part of the lateral cortex has similar efferent connections as the dorsal part and should be regarded as the caudal continuation of the dorsal part. Because previous studies have shown that the medial cortex and the amygdaloid complex project to different hypothalamic areas, we conclude that the dorsal and ventral parts of the lateral cortex transmit olfactory information to separate hypothalamic areas that are probably involved with different types of behavior. © 1995 Wiley-Liss, Inc.     

Trajectory of group Ia and Ib fibers from the hind-limb muscles at the L3 and L4 segments of the spinal cord of the cat

Nineteen physiologically identified group Ia and five group Ib fibers at the L3 and L4 levels of the spinal cord originating from various hind-limb muscles were intraaxonally injected with horseradish peroxidase (HRP). The trajectories of the stained axons were reconstructed. They extended for distances of 8.6 mm-18.0 mm rostrocaudally. Ascending axons ran in various regions of the dorsal funiculus: The ascending axon from a toe muscle (3 microns in diameter) ran in the ventral most part of the paramedian region; those from shank muscles (3.0-5.0 microns) in both dorsal and ventral paramedian regions; those from thigh muscles (5.0-7.0 microns) in both the paramedian and the more lateral regions; and those from hip muscles (6.0-7.0 microns) in the lateral region. Main collaterals arising from the parent fiber were given off at intervals of 0.5-6.2 mm (mean 2.4 mm). Collaterals of a fiber from a toe muscle (1.0 micron in diameter) entered Clarke's column from the dorsomedial side and ramified mostly in the dorsomedial one-third of the column. Collaterals of fibers from shank muscles (1.0-2.0 microns) entered Clarke's column from the dorsal side and terminated in its middle parts as well as in laminae V-VII. Collaterals of fibers from thigh muscles (1.0-2.5 microns) passed lateral to or through the lateral part of Clarke's column and terminated in its ventrolateral part and in laminae V-VIII. Collaterals of fibers from hip muscles (1.5-2.5 microns) passed lateral to Clarke's column and ramified mostly in laminae VII-IX. As the muscle of origin became more proximal, the proportion of termination outside of Clarke's column progressively increased. Thus, the trajectory of group I fibers was somatotopically organized both in the dorsal funiculus and in the gray matter. The long axis of boutons ranged from 0.5 to 17 microns in Ia fibers and from 0.5 to 8 microns in Ib fibers. "Giant" Ia boutons (above 7 microns) were found both in and outside Clarke's column.     

Medial cortex of the lizard Gekko gecko: A hodological study with emphasis on regional specialization

There is increasing evidence that the archicortex in mammals and reptiles is not a homogeneous structure. However, little is known about the regional specialization of this cortical area in reptiles. Therefore, the efferent connections of the medial cortex of the lizard Gekko gecko were studied with the anterograde tracer Phaseolus vulgaris-leucoagglutinin. The small-celled part of the medial cortex (Cxms) projects to various parts of the septum in a topological way: the rostral part projects to the anterior septal nucleus, whereas the caudal part projects to the lateral septal nucleus and the nucleus septi impar. In addition, Cxms projects to the large-celled part of the medial cortex (Cxml). Axons that originate from the dorsal part of Cxms terminate at the proximal parts of the apical and basal dendrites of the neurons of Cxml caudal to the injection site. In contrast, fibers originating from the ventral part terminate on more distal parts of the dendrites of neurons of Cxml rostral to the injection site. Other projections from Cxms to the dorsal cortex (Cxd) and the external amygdaloid nucleus were found. The Cxml projects bilaterally to Cxms. These projections terminate in the superficial and deep plexiform layers. In addition, projections to the cell plate of Unger, Cxd, and to the lateral septal nucleus were found. It appears, on the basis of the efferent connections, that Cxms can be divided into a rostral and caudal part, while hodological differences also exist between the dorsal and ventral parts of Cxms. The results of the present study do not suggest a subdivision of Cxml. The regional variations of the medial cortex in the lizard Gekko gecko differ from the regional variations described in other reptilian species. © 1993 Wiley-Liss, Inc.     

The angioarchitecture of the choroid plexus of the lateral ventricle of the rabbit: A scanning electron microscopic study of vascular corrosion casts

The vascularization of the choroid plexus of the rabbit's lateral ventricle has been studied by scanning electron microscopy of vascular corrosion casts. Based on the vascular patterns discerned, the plexus was subdivided into 6 different parts: the inferior, lateral, central and superior parts, the free margin and the lingula. These differ in structure and localization. While the arterial supply of the inferior part is via the anterior choroidal artery, the central and superior part are supplied by the posterior choroidal arteries. Three main veins leave the plexus and drain to the basilar vein from the inferior part and to the internal cerebral vein from the inferior, central and superior part. Capillary diameters were typically 10-15 micron. Regular nodular thickenings up to 24 micron in diameter were seen in the free margin and the superior, lateral and inferior parts. 'Garland' shaped capillary configurations sheathing arteries as well as veins were found all over the plexus. It is suggested that these 6 different parts of the plexus described here may reflect functionally different areas.     

Mediolateral and dorsoventral projection patterns of cutaneous afferents within transverse planes of the mouse spinal dorsal horn

The central projection patterns of cutaneous afferents from the forelimb and shoulder of mice were studied in the spinal dorsal horn after intracutaneous injection of AlexaFluor 488-conjugated and/or 594-conjugated cholera toxin subunit B (CTB). Based on their dermatomes, the following eight skin regions are thought to be innervated by spinal nerves from the sixth to eighth cervical spinal nerve roots: the dorsal surface of the shoulder, brachium, proximal forearm, distal forearm, hand, palmar surface of the second and third digits, and palm. The termination areas of afferents from the dorsal surface of the shoulder and forearm were narrow, distributed in a dorsoventral direction, and aligned in order from lateral to medial within the sixth to eighth cervical dorsal horns. By contrast, the termination areas of the palmar surface of the second and third digits largely overlapped. We also injected CTB into the dorsal surface of the hindlimb and pelvic regions. Skin regions there are thought to be innervated by nerves from the third to fifth lumbar spinal nerve roots. The observed projection patterns in the lumbar dorsal horn were similar to the cervical patterns. Injection of a mixture of CTB and wheat-germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), which are thought to label Aβ and Aδ/C fibers, respectively, showed segregated termination areas of CTB- and WGA-HRP-labeled afferents. Moreover, alignment of the termination areas was in the dorsoventral direction. These results suggest there is fine somatotopic (mediolateral axis) and modality-specific (dorsoventral axis) organization within the spinal dorsal horn.     

Efferent connections of the dorsal cortex of the lizard Gekko gecko studied with Phaseolus vulgaris-leucoagglutinin

The efferent connections from the dorsal cortex of the lizard Gekko gecko have been studied with the anterograde tracer Phaseolus vulgaris-leucoagglutinin. It appeared that the dorsal cortex is not a homogeneous structure as far as the efferent connections are concerned. All parts of the dorsal cortex project to the septum. All parts except the most medial project to the dorsal ventricular ridge, amygdala, nucleus periventricularis hypothalami, area lateralis hypothalami, and the anterior olfactory nucleus. The most medial part, in addition to the septal projections, is connected with the medial cortex and the contralateral medial and dorsal cortices. From the rostral part additional projections could be traced to the nucleus dorsolateralis hypothalami, nucleus ventromedialis thalami, nucleus dorsolateralis thalami, striatum, pallial thickening, medial cortex, nucleus olfactorius anterior, and the main and accessory olfactory bulbs. From the caudal part additional projections exist to the nucleus dorsomedialis thalami, nucleus accumbens, and the contralateral dorsal cortex. A system of intrinsic connections exists that can be subdivided into four subsystems, each of which subserves the interconnections within four subdivisions of the cortex: 1) the superficial medial part, 2) the deep medial part, 3) the caudal lateral and caudal intermediate parts, and 4) the rostral lateral and rostral intermediate parts. Connections between these four areas are scarce. From the present results the conclusion is drawn that the dorsal cortex of the lizard Gekko gecko has many hodological aspects in common with the ventral subiculum of mammals. The present results do not support the hypothesis that the dorsal cortex is the reptilian equivalent of the mammalian neocortex.     

The specificity of central nervous projections of locust mechanoreceptors

The central projections of hairplates and groups of campaniform sensilla of various parts of the locust head, neck, and thorax are compared. Receptors with approximately the same peripheral location (e.g., dorsal head, wing, or proximal leg) tend to exhibit similar central projection patterns. Specificity of the projections due to different morphological types of sensory neurones may influence shape and extent of segmental ramifications; this is observed with receptors of the proximal leg joints in particular.