岛叶与锥体束空间关系的影像学和解剖学研究

目的研究岛叶与锥体束的空间位置关系,为岛叶病变手术中保护锥体束和减少术后运动功能障碍提供指导。方法2013年3—10月,选取10例健康志愿者采用MR弥散张量纤维束成像( DTT)重建锥体束影像,选取6例成人颅脑标本运用Klingler白质纤维解剖技术解剖岛叶区域显露内囊和放射冠,在标本上进行断层解剖观察并测量岛叶标志点与内囊和放射冠的间距,结合MRI与解剖观察结果,对岛叶与锥体束的空间位置关系进行前瞻性研究。结果岛叶标志点在颅脑标本和MRI中均容易辨认。 DTT重建影像显示锥体束经过了岛叶后上部的深部。在解剖标本利用上中央岛点( UCIP)和后下岛点( PIIP)间连线将岛叶划分成前下部和后上部两个区域。岛叶后上部皮层与锥体束之间为最外囊、屏状核和外囊,而无壳核和苍白球。 UCIP和后上岛点( PSIP)距其深部的放射冠分别为(5.0依0.3)mm和(4.7依0.3)mm,PIIP距其深部的内囊后肢(5.7依0.5)mm。结论利用UCIP和PIIP连线所划分出的岛叶后上部因毗邻锥体束是手术危险区域。岛叶危险区域的划分有助于术前评估手术风险和预后,术中保护锥体束,降低术后运动功能障碍的发生率。     

长期舞蹈训练对白质纤维微结构影响的TBSS比较研究

舞蹈涉及复杂的感觉运动信息处理,长期舞蹈训练可能让脑产生功能与结构的可塑性改变。目前关于舞蹈训练导致的白质结构研究相当有限,缺乏统一的结果,因此对舞蹈家与正常对照组的白质纤维微结构指标进行比较研究,以探索舞蹈家白质纤维微结构的特异性改变。采集18名舞蹈家及与之匹配的25名对照被试的磁共振扩散张量成像(DTI)数据,使用基于纤维束示踪的空间统计分析(TBSS)技术,对被试白质纤维的部分各向异性分数(FA)和平均弥散率(MD)图谱进行体素级别统计分析。采用t检验,对比两组被试数据的差异。结果表明,舞蹈家在涉及感觉运动信息处理的白质纤维微结构的一致性降低:在胼胝体压部、左侧内囊前肢(左侧丘脑辐射前部)、左侧内囊后肢(左侧皮质脊髓束)存在显著降低的FA值,在左侧内囊后肢(含部分左侧下纵束、左侧上纵束与左侧皮质脊髓束)、左侧外囊(含部分下额枕束与钩束)、左侧冠状束前部与胼胝体膝部存在显著升高的MD值。以上结果提示,舞蹈训练可能导致脑内特定白质纤维束的交错更多,连接不同脑区的轴突纤维更为发散,进而影响感觉运动信息的上下行传递与左右脑信息整合效率。同时,长期舞蹈训练可能对主导运动控制的左半脑的白质通路影响明显。     

应用DTI技术对人脑白质纤维束的初步研究

目的建立扩散张量纤维束成像对人脑白质纤维的显示方法,并应用中国数字化可视人体数据进行对照观察,验证扩散张量成像(DTI)方法的可靠性。方法选择5名健康志愿者进行DTI成像,采用DtiStudio软件进行分析处理,重建出部分各向异性(FA)图、容积比(VR)图、相对各向异性(RA)图、表面扩散系数(ADC)图以及二维彩色张量图。应用中国数字化可视人体数据集断面图像、FA图及彩色FA图进行对照观察,利用fibertracking纤维跟踪软件及3DMRI软件进行三维重建显示脑内主要白质纤维束,辨认脑内白质纤维束的位置、形态。结果应用DTI纤维束成像可以清晰准确地描绘脑白质内主要神经纤维束的解剖图谱,包括联络纤维如弓形纤维、钩束、扣带束、上纵束和下纵束,连合纤维如胼胝体、前连合和穹隆,投射纤维如锥体束、视放射、内侧丘系等。DTI纤维束成像结果与已知解剖知识、中国可视化人体断面图像具有很好的一致性。结论应用DTI纤维束成像可以清晰准确地描绘脑白质内主要神经纤维束的解剖图谱,其结果与中国可视化人体断面图像、已知解剖知识是一致的,应用DTI纤维束成像研究脑内纤维连通性是可靠的。     

膝关节后纵隔与后交叉韧带下止点的解剖关系及临床意义

目的 探讨膝关节后纵隔与后交叉韧带(PCL)下止点的解剖关系及其在PCL重建中的临床价值. 方法 解剖22例新鲜冷冻膝关节,将PCL在屈膝90°下按纤维张力的不同分为前外束和后内束,解剖出它们在胫骨上的足迹,并用墨汁标记足迹的轮廓;使用带标尺的数码相机测量PCL前外束、后内束胫骨止点中心点与后纵隔的水平距离,并同时测量两束止点中心点与外侧胫骨平台后软骨缘上表面的垂直距离. 结果 膝关节存在一个从前至后的纵隔结构,其前方与脂肪垫、翼状皱襞或黏膜韧带相连,中间位于前、后交叉韧带之间,后方形成膝关节的后纵隔.在22个膝关节中,8个膝关节的后纵隔从PCL的外缘绕过以后止于后关节囊,占36.36%;14个膝关节的后纵隔在PCL前方分叉,包绕PCL后止于后关节囊,占63.64%.PCL前外束胫骨止点中心点距离后纵隔内侧的水平距离(0.90±2.40)mm,距离外侧胫骨平台后软骨缘上表面的垂直距离是(3.25±1.20)mm.后内束胫骨止点中心点距离后纵隔内侧的水平距离为(4.35±2.46)mm,距离外侧胫骨平台后软骨缘上表面的垂直距离为(6.91±1.57)mm. 结论 膝关节后纵隔与PCL下止点的解剖关系密切,后纵隔可以成为PCL单束重建和双束重建手术中胫骨止点定位的重要解剖标志之一.     

内镜锁孔经小脑幕-侧副沟入路显露侧脑室的解剖学研究

目的 探讨神经内镜经小脑幕-侧副沟入路显露侧脑室三角区的可行性及相关技术要点。方法 以成人尸头标本10具(20侧)作为研究对象。取5具尸头的大脑标本,观察侧脑室三角区及其相关解剖结构;测量胼胝体压部后极至枕极(枕叶后极)的垂直距离,大脑经胼胝体压部后极行冠状位切开,测量侧副沟底部至侧脑室三角区底面的最短距离。在另外5具尸头标本上模拟行神经内镜经小脑幕-侧副沟入路手术以显露侧脑室三角区,观察并记录入路相关解剖结构。结果 侧副沟与侧脑室的位置关系相对恒定,视辐射纤维覆盖侧脑室的外侧壁。胼胝体压部后极至枕极的平均垂直距离为(41.26±2.78)mm;大脑经胼胝体压部后极的冠状位切开,测量侧副沟底部至侧脑室三角区底面的平均最短距离为(4.24±0.98)mm。通过枕部旁正中的锁孔骨窗,神经内镜经小脑幕-侧副沟模拟手术均成功完成,通过由下向上的视角可清晰显露侧脑室的三角区以及体后部。结论 神经内镜经小脑幕-侧副沟入路可以有效显露侧脑室的三角区及体后部,且避免损伤视辐射及语言功能区,可作为部分侧脑室肿瘤的手术备选方案。     

小儿大脑大静脉的应用解剖

为提供小儿大脑大静脉的应用解剖学资料,本文分组观察了75例小儿大脑大静脉的形态和行程,测量了大脑大静脉与松果体、胼胝体压部和直窦间的位置关系,结合松果体区肿瘤、大脑大静脉畸形等疾病的诊治讨论了与之有关的临床应用问题.     

膝关节前交叉韧带后外束股骨止点位置的解剖

目的 通过对膝关节前交叉韧带后外束股骨止点的解剖测量,找到确定前交叉韧带后外束股骨止点的简单可行的方法,为双束重建前交叉韧带手术中的骨道定位提供理论依据。方法 解剖20例新鲜膝关节标本（25~45岁）。在屈膝90°位,测量前交叉韧带后外束股骨止点中心点距股骨髁间窝外侧壁前方、后方和下方软骨缘的距离,再对测量数据进行评估和对比。结果前交叉韧带后外束股骨止点中心点距离股骨前方软骨缘(8.74±1.39)mm,距离后方软骨缘(8.69±1.57)mm（P =0.926）。后外束止点中心点距离股骨下方软骨缘(5.06±0.77)mm。结论膝关节屈膝90°位时,前交叉韧带后外束的股骨止点中心点位于股骨髁间窝外侧壁,距离下方软骨缘5mm,距离前方和后方软骨缘的距离相等。在前交叉韧带双束重建的手术中,应用本研究的结果能够简单、快捷地确定前交叉韧带后外束股骨骨道位置。     

前庭导水管解剖与CT对照研究

目的：测量和了解在体前庭导水管（vestibular aqueduct，VA）CT解剖形态和正常大小。方法：（1）26块颞骨标本解剖和CT轴位扫描，观察和测量VA的解剖结构及其与周围重要结构（骨性半规管、内听道）的位置关系。（2）对36例临床诊断为单纯性中耳炎，无眩晕和明显听力障碍者进行颞骨轴位CT扫描图像进行VA的观察和测量，并与标本解剖图像和数据对照。结果：VA解剖形态呈倒“J”字形，外口形态多样，CT上VA内侧段难显示，外侧段短线状小管，内径1mm左右，VA外口前后径1-10mm，平均7．5mm。活体螺旋CT83％显示VA外口、67％显示外周段。结论：前庭导水管位置、形态固定。VA外口变异大，CT上难以准确测量其大小，因此不能单凭测量的数据判断VA发育情况。     

经皮层侧脑室后锁孔入路的显微解剖研究

目的：在显微镜下观测侧脑室三角区的解剖结构,探讨经皮层侧脑室后锁孔入路的可行性,为临床应用提供解剖学依据。方法2009年9月—2011年5月选择10具(20侧)正常成人尸头标本,模拟经皮层侧脑室后锁孔入路手术,进入侧脑室三角区,在显微镜下对所暴露的脑室系统及其内部结构进行解剖观察,并测量顶内沟与中央后沟交点(顶内点)和大脑纵裂的距离、顶内沟的深度、顶内沟底部至三角区皮质厚度。结果经顶内沟侧脑室后锁孔入路进入侧脑室,显微镜下可观察到：侧脑室三角区的底部为侧副三角;前壁内侧为穹窿脚,外侧为丘脑枕;内侧壁上部为胼胝体球,下部为禽距;外侧壁为尾状核围绕丘脑枕部形成。侧脑室三角区的脉络丛有一明显突起,即脉络丛球;脉络丛向外侧伸入侧脑室颞角,向前部伸向侧脑室体部,侧脑室枕角没有脉络丛。测量顶内沟与中央后沟的交点至大脑纵裂的距离为(35.36±1.06)mm;顶内沟的深度为(19.16±1.03)mm,顶内沟底部至三角区皮质厚度为(21.31±1.32) mm。结论经皮层侧脑室后锁孔入路可避免术中对皮层的牵拉、减轻对脑组织的挫伤、缩短到达脑室的距离,并可清晰地显露侧脑室三角区的解剖结构,通过相关数据的测量可帮助术中定位顶内沟及判断是否进入侧脑室。对位于侧脑室体后部和三角区内的病变,采用此手术入路具有临床可行性。     

完全神经内镜下经Poppen锁孔入路松果体区手术的应用解剖学研究

目的 解剖观察完全神经内镜下经Poppen锁孔入路开颅松果体区手术的相关解剖结构及其特征,并探讨该术式的可行性。方法 选取12具经10%甲醛固定、红蓝乳胶灌注的成人尸头湿标本进行实验观察,其中男7例、女5例,年龄34~71岁。应用随机数字表法将12具标本随机分为内镜组和显微组,每组6具,分别采用完全神经内镜Poppen锁孔入路和显微镜常规Poppen入路进行模拟开颅手术松果体区手术。模拟手术中,利用神经导航对松果体区以及手术间隙进行观察测量：（1）观察2组松果体区重要解剖结构;（2）内镜组术中,于剪开小脑幕前后,分别测量松果体区暴露面积,并采用配对t检验进行比较;（3）内镜组与显微镜组术中,分别测量第1、2、3手术间隙的暴露面积,并采用独立样本t检验进行组间比较;（4）其他重要解剖结构间距的神经内镜测量。结果 （1）2种入路均可观察到双侧基底静脉、小脑中脑裂静脉、大脑内静脉、大脑后动脉、小脑上动脉等重要血管,以及滑车神经、四叠体、胼胝体压部和松果体等重要解剖结构,但显微镜常规Poppen入路的手术通道狭窄、倾斜,视野局限。（2）内镜组模拟手术中,剪开小脑幕前后松果体区显露面积分别为（73.14±3.38）mm²和（127.77±7.90）mm²,剪开后明显大于剪开前,差异有统计学意义（t=28.84,P<0.001）。（3）内镜组和显微镜组模拟手术中,第1、2、3手术间隙的暴露面积分别为（20.93±2.49）mm²、（72.55±4.18）mm²、（208.57±11.79）mm²和（9.12±1.12）mm²、（53.45±3.17）mm²、（175.29±9.98）mm²,内镜组均大于显微镜组,差异均有统计学意义（t=14.92、12.61、7.41,P值均<0.001）。（4）神经内镜测量显示：双侧基底静脉最大距离为（14.41±0.94）mm,双侧小脑中脑裂静脉最大距离为（8.23±0.84）mm,双侧大脑内静脉最大距离为（8.41±0.96）mm,双侧大脑内静脉最小距离（第1间隙最窄长度）为（2.58±0.22）mm,松果体中心点至丘脑枕部中心点距离为（16.83±1.16）mm。结论 完全神经内镜下经Poppen锁孔入路模拟手术中间隙恒定,可安全到达松果体区;与显微镜常规Poppen入路相比,完全神经内镜Poppen锁孔入路的手术操作空间更大,松果体区显露得更充分。     

Fiber tracts that contain more opioid binding sites than gray matter does: a quantitative autoradiographic study in the guinea-pig

Opioid binding sites were localized in cryostat sections of guinea-pig brain by in vitro autoradiography using (-)-[3H]bremazocine. Quantification of binding sites in gray matter was accomplished using standard samples of tritium mixed in brain gray matter. The binding sites in fiber tracts were quantified using standards made from white matter to compensate for the quenching caused by myelin. Binding in gray matter corroborated previous findings that the moderately high densities of opioid sites in the cerebellum are of the kappa type, and that the V and VI laminae of the cerebral cortex, the substantia nigra, and olfactory bulb contain high levels of opioid sites in the guinea-pig. Several fiber tracts such as cerebellar white matter and the corpus callosum contained densities of (-)-[3H]bremazocine binding sites equal to, or higher than, the most densely labeled gray matter areas. The dorsal hippocampal commissure and the splenium of the corpus callosum contained 2200 fmol sites/mg protein, two and one half times more than the most densely labeled gray matter areas, the external plexiform layer of the olfactory bulb. These sites may be receptors in transport, but their density constitutes a massive volume of receptors for which a physiological role still needs to be more clearly defined.     

基于机器学习的睡眠剥夺注意力易损性分类研究

目的:旨在寻找可以对睡眠剥夺后注意力易损与耐受个体进行准确区分的白质纤维束。方法:借助弥散张量成像技术获取各向异性分数、轴向扩散系数、径向扩散系数及平均扩散系数等反映白质弥散特性的特征参数,使用支持向量机分类算法构建睡眠剥夺易损性分类模型;采用准确性、敏感性、特异性、阳性预测值和阴性预测值等指标评价分类模型的性能表现;采用置换检验评估分类模型的显著性。结果:与只采用单一类型特征相比,使用组合特征构建的分类器表现性能最佳,其准确性、敏感性、特异性、阳性预测值、阴性预测值及曲线下面积分别为83.67%、80.00%、87.50%、86.96%、80.77%、88.67%。在组合特征构建的分类模型中对分类贡献较大的白质纤维束主要包括放射冠、内囊前肢、丘脑后辐射及皮质脊髓束等投射纤维、上纵束和扣带等联络纤维以及胼胝体和穹窿联合等联合纤维。结论:特定脑区间白质纤维束的微观结构特性可以作为区分睡眠剥夺后注意力易损与耐受个体的影像学标志物。     

Diffusion tensor imaging in studying white matter complexity: A gap junction hypothesis

The role of the prefrontal cortex as an executive oversight of posterior brain regions raises the question of the extent to which the anterior regions of the brain interconnect with the posterior regions. The aim of this study is to test the complexity of rostral white matter tracts, which connect anterior and posterior brain regions, in comparison to caudal white matter tracts and the corpus callosum. Diffusion tensor imaging (DTI) is a modality that measures fractional anisotropy (FA). Higher white matter complexity could result in a decrease of FA, possibly through denser intersection of fiber tracts. DTI was used to determine regional FA in 9 healthy bonnet macaques (Macaca radiata). Four regions of interest were included: anterior and posterior limbs of the internal capsule, the occipital lobe white matter, and the corpus callosum. FA of the anterior limbs of the internal capsule was lowest compared to all other regions of interest (Newman–Keuls (N–K); p < 0.0001), whereas FA of the corpus callosum was highest (N–K; p < 0.0001). The posterior limbs of the internal capsule and the occipital white matter were not distinguishable but exhibited intermediate FA in comparison to the former (N–K; p < 0.0001) and the latter (N–K; p < 0.0001). The current study demonstrates that FA, a measure of white matter complexity, can vary markedly as a function of region of interest. Moreover, validation of these findings using neurohistological studies and replication in human samples appears warranted.     

人脑松果体区域的断面解剖学研究

应用断面解剖学方法，对３３例（男１８，女１５）头颅标本的松果体及其眦邻结构进行了观测。结果发现：有８７．８８％的松果体中点偏离中线，偏离中线的平均距离及与之对应的移位百分率是：左移０．９９ｍｍ（０．８０％），右移０．７１ｍｍ（０．５４％）；松果体及第三脑室长径、宽径均无性差，经松果体中点半球宽存在侧差（左侧〈右侧）和性差（男〉女），左、右半球长径存在性差（男〉女）；此外，本文应用逐步回归方法对松果     

基于纤维束空间统计学的吸烟成瘾青少年左右脑白质不对称研究

目的:观察吸烟成瘾青少年左右脑白质结构的不对称性变化。 方法:采用基于纤维束空间统计（TBSS）的分析方法,对23名青少年吸烟成瘾者的脑白质弥散张量成像（DTI）数据进行处理,观察分析出现左右脑白质结构异常不对称的脑区。 结果:通过分析,我们发现青少年成瘾者的脑白质在胼胝体部、胼胝体膝部、胼胝体压部、前放射冠、内囊前肢等脑区处的左右脑白质不对称差异值较大（FWE校正后P<0.05）。Pearson相关分析显示在胼胝体部（r=0.431, P=0.040）、胼胝体膝部（r=0.429, P=0.041）、前放射冠（r=0.477, P=0.021）这些脑区的轴向弥散率（AD）与尼古丁依赖量表（FTND）程度分数呈显著正相关,胼胝体压部与FTND呈显著负相关（r=-0.450, P=0.031）。胼胝体膝部的分数各向异性与FTND呈现显著正相关（r=0.678, P=0.000）。前放射冠的AD与吸烟指数包年（pack-year）呈现显著正相关（r=0.493, P=0.017）。 结论:青少年吸烟成瘾者的胼胝体,前放射冠等脑区的脑白质表现出了异常的左右不对称。     

人参皂苷Rbl对大鼠局灶性脑缺血白质重塑的影响

目的　探讨人参皂苷Rbl(Ginsenoside Rb1,GSRb1)对大鼠局灶性脑缺血白质重塑的影响。 方法　大鼠随机分为假手术组、溶媒处理组和人参皂苷Rbl处理组,采用线栓法建立大鼠大脑中动脉缺血再灌注（middle cerebral artery occlusion/reperfusion, MCAO/R）损伤模型,用LFB染色观察大鼠胼胝体和内囊的髓鞘变化,用免疫组化染色法检测缺血侧胼胝体GFAP和APP的表达以评估星形胶质细胞和轴突的改变。 结果　缺血2 h再灌72 h后,溶媒处理组胼胝体和内囊有明显的髓鞘紊乱、脱失,胼胝体GFAP和APP表达显著增加。与溶媒处理组相比,GSRb1处理组髓鞘脱失有明显改善 (P<0. 01, P<0. 05)且胼胝体GFAP和APP表达显著减少(P<0. 05)。 结论　GSRb1可能促进大鼠局灶性脑缺血后脑白质重塑。     

White matter damage of patients with Alzheimer’s disease correlated with the decreased cognitive function

Increasing evidence demonstrates that there is marked damage and dysfunction in the white matter in Alzheimer’s disease (AD). The present study investigates the nature of white matter damage of patients with Alzheimer’s disease with diffusion tensor magnetic resonance imaging (DTI) and analyses the relationship between the white matter damage and the cognition function. DTI, as well as T1 fluid attenuated inversion recovery (FLAIR) and T2-FLAIR, was performed on probable patients of Alzheimer’s disease, and sex and age matched healthy volunteers to measure the fractional anisotropy (FA) and mean diffusivity (MD) in the genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, and the white matter of frontal, temporal, parietal, and occipital lobes. FA was lower in the splenium of corpus callosum, as well as in the white matter of the frontal, temporal, and parietal lobes from patients with Alzheimer’s disease than in the corresponding region from healthy controls and was strongly positive correlated with MMSE scores, whereas FA appeared no different in the anterior and posterior limbs of internal capsule, occipital lobes white matter, and the genu of corpus callosum between the patients and healthy controls. MD was significantly higher in the splenium of corpus callosum and parietal lobes white matter from patients than in that those from healthy controls and was strongly negative correlated with MMSE scores, whereas MD in the anterior and posterior limbs of internal capsule, as well as in frontal, temporal, occipital lobes white matter and the genu of corpus callosum, was not different between the patients and healthy controls. The most prominent alteration of FA and MD was in the splenium of corpus callosum. Our results suggested that white matter of patients with Alzheimer’s disease was selectively impaired and the extent of damage had a strong correlation with the cognitive function, and that selective impairment reflected the cortico–cortical and cortico–subcortical disconnections in the pathomechanism of Alzheimer’s disease. The values of FA and MD in white matter, especially in the splenium of corpus callosum in AD patients, might be a more appropriate surrogate marker for monitoring the disease progression.     

A comparative study of bone marrow mesenchymal stem cell functionality in C57BL and mdx mice

Abnormalities of the white matter (WM) tracts integrity in brain areas involved in emotional regulation have been postulated in major depressive disorder (MDD). However, there is no diffusion tensor imaging (DTI) study in patients with treatment-responsive MDD at present. DTI scans were performed on 22 patients with treatment-responsive MDD and 19 well-matched healthy subjects. Tract-based spatial statistics (TBSS) approach was employed to analyze the scans. Voxel-wise statistics revealed four brain WM tracts with lower fractional anisotropy (FA) in patients compared to healthy subjects: the bilateral internal capsule, the genu of corpus callosum, the bilateral anterior corona radiata, and the right external capsule. FA values were nowhere higher in patients compared to healthy subjects. Our findings demonstrate that the abnormalities of the WM tracts, major in the projection fibers and corpus callosum, may contribute to the pathogenesis of treatment-responsive MDD.     

Anatomy and White Matter Connections of the Superior Frontal Gyrus

The superior frontal gyrus (SFG) is an important region implicated in a variety of tasks including motor movement, working memory, resting-state, and cognitive control. A detailed understanding of the subcortical white matter of the SFG could improve postoperative morbidity related to surgery around this gyrus. Through DSI-based fiber tractography validated by gross anatomical dissection, we characterized the fiber tracts of the SFG based on their relationships to other well-known neuroanatomic structures. Diffusion imaging from the Human Connectome Project from 10 healthy adult subjects was used for fiber tractography. We evaluated the SFG as a whole based on its connectivity with other regions. All tracts were mapped in both hemispheres, and a lateralization index was calculated based on resultant tract volumes. Ten cadaveric dissections were then performed using a modified Klingler technique to delineate the location of major tracts integrated within the SFG. We identified four major SFG connections: the frontal aslant tract connecting to the inferior frontal gyrus; the inferior fronto-occipital fasciculus connecting to the cuneus, lingual gyrus, and superior parietal lobule; the cingulum connecting to the precuneus and parahippocampal gyrus/uncus; and a callosal fiber bundle connecting the SFG bilaterally. The functional networks of the SFG involve a complex series of white matter tracts integrated within the gyrus, including the FAT, IFOF, cingulum, and callosal fibers. Postsurgical outcomes related to this region may be better understood in the context of the fiber-bundle anatomy highlighted in this study. Clin. Anat. 33:823–832, 2020. © 2019 Wiley Periodicals, Inc.     

Populations of subplate and interstitial neurons in fetal and adult human telencephalon

In the adult human telencephalon, subcortical (gyral) white matter contains a special population of interstitial neurons considered to be surviving descendants of fetal subplate neurons [Kostovic & Rakic (1980) Cytology and the time of origin of interstitial neurons in the white matter in infant and adult human and monkey telencephalon. J Neurocytol9, 219]. We designate this population of cells as superficial (gyral) interstitial neurons and describe their morphology and distribution in the postnatal and adult human cerebrum. Human fetal subplate neurons cannot be regarded as interstitial, because the subplate zone is an essential part of the fetal cortex, the major site of synaptogenesis and the 'waiting' compartment for growing cortical afferents, and contains both projection neurons and interneurons with distinct input-output connectivity. However, although the subplate zone is a transient fetal structure, many subplate neurons survive postnatally as superficial (gyral) interstitial neurons. The fetal white matter is represented by the intermediate zone and well-defined deep periventricular tracts of growing axons, such as the corpus callosum, anterior commissure, internal and external capsule, and the fountainhead of the corona radiata. These tracts gradually occupy the territory of transient fetal subventricular and ventricular zones.The human fetal white matter also contains distinct populations of deep fetal interstitial neurons, which, by virtue of their location, morphology, molecular phenotypes and advanced level of dendritic maturation, remain distinct from subplate neurons and neurons in adjacent structures (e.g. basal ganglia, basal forebrain). We describe the morphological, histochemical (nicotinamide-adenine dinucleotide phosphate-diaphorase) and immunocytochemical (neuron-specific nuclear protein, microtubule-associated protein-2, calbindin, calretinin, neuropeptide Y) features of both deep fetal interstitial neurons and deep (periventricular) interstitial neurons in the postnatal and adult deep cerebral white matter (i.e. corpus callosum, anterior commissure, internal and external capsule and the corona radiata/centrum semiovale). Although these deep interstitial neurons are poorly developed or absent in the brains of rodents, they represent a prominent feature of the significantly enlarged white matter of human and non-human primate brains.