scholarly journals Composition and organization of the sagittal stratum in the human brain: a fiber dissection study

2021 ◽  
pp. 1-9
Author(s):  
Igor Lima Maldonado ◽  
Christophe Destrieux ◽  
Eduardo Carvalhal Ribas ◽  
Bruna Siqueira de Abreu Brito Guimarães ◽  
Patrícia Pontes Cruz ◽  
...  
Keyword(s):  
Anterior Commissure ◽  
Spatial Arrangement ◽  
Surgical Approaches ◽  
Layer By Layer ◽  
Small Contribution ◽  
Inferior Longitudinal Fasciculus ◽  
Cerebral Parenchyma ◽  
Fundamental Research ◽  
Fiber Dissection ◽  
Optic Radiations

OBJECTIVEThe sagittal stratum is divided into two layers. In classic descriptions, the stratum sagittale internum corresponds to optic radiations (RADs), whereas the stratum sagittale externum corresponds to fibers of the inferior longitudinal fasciculus. Although advanced for the time it was proposed, this schematic organization seems simplistic considering the recent progress on the understanding of cerebral connectivity and needs to be updated. Therefore, the authors sought to investigate the composition of the sagittal stratum and to detail the anatomical relationships among the macroscopic fasciculi.METHODSThe authors performed a layer-by-layer fiber dissection from the superolateral aspect to the ventricular cavity in 20 cadaveric human hemispheres.RESULTSDiverse bundles of white matter were observed to contribute to the sagittal stratum and their spatial arrangement was highly consistent from one individual to another. This was the case of the middle longitudinal fasciculus, the inferior fronto-occipital fasciculus, the RADs, and other posterior thalamic radiations directed to nonvisual areas of the cerebral cortex. In addition, small contributions to the sagittal stratum came from the anterior commissure anteriorly and the inferior longitudinal fasciculus inferiorly.CONCLUSIONSA general model of sagittal stratum organization in layers is possible, but the composition of the external layer is much more complex than is mentioned in classic descriptions. A small contribution of the inferior longitudinal fasciculus is the main difference between the present results and the classic descriptions in which this bundle was considered to entirely correspond to the stratum sagittale externum. This subject has important implications both for fundamental research and neurosurgery, as well as for the development of surgical approaches for the cerebral parenchyma and ventricular system.

Anatomy of the Anterior Temporal Lobe and the Frontotemporal Region Demonstrated by Fiber Dissection

Neurosurgery ◽  
2004 ◽  
Vol 55 (5) ◽  
pp. 1174-1184 ◽  
Author(s):  
Diedrik Peuskens ◽  
Johannes van Loon ◽  
Frank Van Calenbergh ◽  
Raymond van den Bergh ◽  
Jan Goffin ◽  
...  
Keyword(s):  
White Matter ◽  
Temporal Lobe ◽  
Anterior Commissure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Surgical Approaches ◽  
Anterior Temporal Lobe ◽  
White Matter Tracts ◽  
Fiber Dissection ◽  
Dissection Technique

Abstract OBJECTIVE: The white matter structure of the anterior temporal lobe and the frontotemporal region is complex and not well appreciated from the available neurosurgical literature. The fiber dissection method is an excellent means of attaining a thorough knowledge of the three-dimensional structure of the white matter tracts. This study was performed to demonstrate the usefulness of the dissection technique in understanding the white matter anatomy and the effects of current surgical approaches on the subcortical structure of the region. METHODS: Seventeen brain specimens obtained at routine autopsy were dissected by use of Klingler's fiber dissection technique after preparation by fixation and freezing. The dissections were performed with an operating microscope and followed a stepwise pattern of progressive white matter dissection. RESULTS: The dissection is described in an orderly fashion showing the white matter tracts of the anterior temporal lobe and the frontotemporal region. An insight is gained into the three-dimensional course of the anterior loop of the optic radiation, the temporal stem, the anterior commissure, and the ansa peduncularis. CONCLUSION: The anterior temporal lobe and the frontotemporal region contain several important white matter tracts that can be uniquely understood by performing a white matter dissection of the region. Surgical procedures on the anterior temporal lobe differ substantially as to their repercussions on the subcortical white matter tract anatomy, as shown by the findings in this study.

Optic radiations: a microsurgical anatomical study

2006 ◽  
Vol 105 (2) ◽  
pp. 294-300 ◽  
Author(s):  
Johann Peltier ◽  
Nadine Travers ◽  
Christophe Destrieux ◽  
Stéphane Velut
Keyword(s):  
Lateral Ventricle ◽  
Average Distance ◽  
Morphological Characteristics ◽  
Anatomical Study ◽  
The Body ◽  
Surgical Approaches ◽  
Optic Radiation ◽  
Fiber Dissection ◽  
Dissection Technique ◽  
Optic Radiations

Object In this study, the authors used a fiber-dissection technique to describe the optic radiation. They focused on the morphological characteristics (length and breadth) of this structure, its course, and its relationships with neighboring fasciculi and the lateral ventricle. Methods The authors dissected 10 previously frozen, formalin-fixed human brains with the aid of an operating microscope by following the fiber dissection technique described by Klingler in 1960. Lateral, inferior, and medial approaches were made. The optic radiation, also known as the Gratiolet radiation, extended from the lateral geniculate body to the calcarine fissure. The average distance from the tip of the anterior Meyer loop to the calcarine sulcus was 105 mm (range 95–114 mm). The breadth of the optic radiations, one on each side of the brain, averaged 17 mm at the level of the inferior horn (range 15–18 mm). This tract could be divided into three main segments: the anterior or Meyer loop, the body, and the end of the optic radiation. Adjacent anatomical structures included: laterally, the inferior longitudinal fasciculi; medially, the tapetum of the corpus callosum; and the ependyma of the inferior horn of the lateral ventricle. Conclusions Various practical surgical approaches are discussed. The knowledge gained by studying this particular anatomy will help prevent injury to the optic radiations during neurosurgery.

scholarly journals The white matter tracts of the cerebrum in ventricular surgery and hydrocephalus

2017 ◽  
Vol 126 (3) ◽  
pp. 945-971 ◽  
Author(s):  
Abuzer Güngör ◽  
Serhat Baydin ◽  
Erik H. Middlebrooks ◽  
Necmettin Tanriover ◽  
Cihan Isler ◽  
...  
Keyword(s):  
White Matter ◽  
Anterior Commissure ◽  
Internal Capsule ◽  
Surgical Approaches ◽  
White Matter Tracts ◽  
Lateral Ventricles ◽  
Fiber Dissection ◽  
Dissection Technique ◽  
Relationship Of ◽  
The Relationship

OBJECTIVE The relationship of the white matter tracts to the lateral ventricles is important when planning surgical approaches to the ventricles and in understanding the symptoms of hydrocephalus. The authors' aim was to explore the relationship of the white matter tracts of the cerebrum to the lateral ventricles using fiber dissection technique and MR tractography and to discuss these findings in relation to approaches to ventricular lesions. METHODS Forty adult human formalin-fixed cadaveric hemispheres (20 brains) and 3 whole heads were examined using fiber dissection technique. The dissections were performed from lateral to medial, medial to lateral, superior to inferior, and inferior to superior. MR tractography showing the lateral ventricles aided in the understanding of the 3D relationships of the white matter tracts with the lateral ventricles. RESULTS The relationship between the lateral ventricles and the superior longitudinal I, II, and III, arcuate, vertical occipital, middle longitudinal, inferior longitudinal, inferior frontooccipital, uncinate, sledge runner, and lingular amygdaloidal fasciculi; and the anterior commissure fibers, optic radiations, internal capsule, corona radiata, thalamic radiations, cingulum, corpus callosum, fornix, caudate nucleus, thalamus, stria terminalis, and stria medullaris thalami were defined anatomically and radiologically. These fibers and structures have a consistent relationship to the lateral ventricles. CONCLUSIONS Knowledge of the relationship of the white matter tracts of the cerebrum to the lateral ventricles should aid in planning more accurate surgery for lesions within the lateral ventricles.

Central core of the cerebrum

2011 ◽  
Vol 114 (2) ◽  
pp. 463-469 ◽  
Author(s):  
Chan-Young Choi ◽  
Seong-Rok Han ◽  
Gi-Taek Yee ◽  
Chae-Heuck Lee
Keyword(s):  
White Matter ◽  
Caudate Nucleus ◽  
Anterior Commissure ◽  
Central Core ◽  
Surgical Approaches ◽  
Fasciculus Retroflexus ◽  
Complex Anatomy ◽  
Fiber Dissection ◽  
Mammillothalamic Tract ◽  
Dissection Technique

Object The purpose of this study was to understand 3D relationships of white matter fibers and subcortical areas of gray matter in the central core. Methods The lateral and medial aspects of 4 cerebral hemispheres were dissected, applying the fiber dissection technique under the microscope. Results The central core between the insula and midline includes the extreme, external, and internal capsules; claustrum; putamen; globus pallidus; caudate nucleus; amygdala; diencephalon; substantia innominata; fornix; anterior commissure; mammillothalamic tract; fasciculus retroflexus; thalamic peduncles, including optic and auditory radiations; ansa peduncularis; thalamic fasciculus; and lenticular fasciculus. It is attached to the remainder of the cerebral hemisphere by the cerebral isthmus, which is composed of white matter fibers located between the dorsolateral margin of the caudate nucleus and the full circumference of the circular sulcus of insula. The rostral fibers of the corpus callosum are included in the frontal portion of the cerebral isthmus. Conclusions It is very useful for neurosurgeons to facilitate the understanding of spatial relationships and pertinent surgical approaches in and around the central core with a highly complex anatomy by using fiber dissection.

Microsurgical and Tractographic Anatomical Study of Transtemporal-Transchoroidal Fissure Approaches to the Ambient Cistern

2020 ◽  
Author(s):  
Emrah Egemen ◽  
Pinar Celtikci ◽  
Yücel Dogruel ◽  
Fatih Yakar ◽  
Defne Sahinoglu ◽  
...  
Keyword(s):  
White Matter ◽  
Anterior Commissure ◽  
Temporal Cortex ◽  
Anatomical Study ◽  
Middle Temporal Gyrus ◽  
Detailed Knowledge ◽  
Fiber Tractography ◽  
Human Connectome Project ◽  
Fiber Dissection ◽  
Ambient Cistern

Abstract BACKGROUND Approaching ambient cistern lesions is still a challenge because of deep location and related white matter tracts (WMTs) and neural structures. OBJECTIVE To investigate the white matter anatomy in the course of 3 types of transtemporal-transchoroidal fissure approaches (TTcFA) to ambient cistern by using fiber dissection technique with translumination and magnetic resonance imaging fiber tractography. METHODS Eight formalin-fixed cerebral hemispheres were dissected on surgical corridor from the temporal cortex to the ambient cistern by using Klingler's method. The trans-middle temporal gyrus, trans-inferior temporal sulcus (TITS), and trans-inferior temporal gyrus (TITG) approaches were evaluated. WMTs that were identified during dissection were then reconstructed on the Human Connectome Project 1021 individual template for validation. RESULTS The trans-middle gyrus approach interrupted the U fibers, arcuate fasciculus (AF), the ventral segment of inferior frontoocipital fasciculus (IFOF), the temporal extensions of the anterior commissure (AC) posterior crura, the tapetum (Tp) fibers, and the anterior loop of the optic radiation (OR). The TITS approach interrupted U fibers, inferior longitudinal fasciculus (ILF), IFOF, and OR. The TITG approach interrupted the U fibers, ILF, and OR. The middle longitudinal fasciculus, ILF, and uncinate fasciculus (UF) were not interrupted in the trans-middle gyrus approach and the AF, UF, AC, and Tp fibers were not interrupted in the TITS/gyrus approaches. CONCLUSION Surgical planning of the ambient cistern lesions requires detailed knowledge about WMTs. Fiber dissection and tractography techniques improve the orientation during surgery and may help decrease surgical complications.

scholarly journals Freeform printing of heterotypic tumor models within cell-laden microgel matrices

2020 ◽  
Author(s):  
Thomas G. Molley ◽  
Gagan K. Jalandhra ◽  
Stephanie R. Nemec ◽  
Aleczandria S. Tiffany ◽  
Brendan A. C. Harley ◽  
...  
Keyword(s):  
Cell Types ◽  
Hierarchical Organization ◽  
Layer By Layer ◽  
Direct Writing ◽  
Tissue Microenvironment ◽  
Fundamental Research ◽  
Multiple Cell ◽  
Different Cell Types ◽  
Local Stiffness

AbstractThe tissue microenvironment is comprised of a complex assortment of multiple cell types, matrices, membranes and vessel structures. Emulating this complex and often hierarchical organization in vitro has proved a considerable challenge, typically involving segregation of different cell types using layer-by-layer printing or lithographically patterned microfluidic devices. Bioprinting in granular materials is a new methodology with tremendous potential for tissue fabrication. Here, we demonstrate the first example of a complex tumor microenvironment that combines direct writing of tumor aggregates, freeform vasculature channels, and a tunable macroporous matrix as a model to studying metastatic signaling. Our photocrosslinkable microgel suspensions yield local stiffness gradients between particles and the intervening space, while enabling the integration of virtually any cell type. Using computational fluid dynamics, we show that removal of a sacrificial Pluronic ink defines vessel-mimetic channel architectures for endothelial cell linings. Pairing this vasculature with 3D printing of melanoma aggregates, we find that tumor cells within proximity migrated into the prototype vasculature. Together, the integration of perfusable channels with multiple spatially defined cell types provides new avenues for modelling development and disease, with scope for fundamental research and drug development.

scholarly journals Letter to the Editor: Optic radiations and anterior commissure

2015 ◽  
Vol 123 (3) ◽  
pp. 824-826
Author(s):  
Abhidha Shah ◽  
Sukhdeep Singh Jhawar ◽  
Atul Goel
Keyword(s):  
Anterior Commissure ◽  
Letter To The Editor ◽  
Optic Radiations

A Novel HOG Descriptor with Spatial Multi-Scale Feature for FER

2014 ◽  
Vol 596 ◽  
pp. 322-327
Author(s):  
Ying Tong ◽  
Liang Bao Jiao ◽  
Xue Hong Cao
Keyword(s):  
Processing Time ◽  
Recognition Rate ◽  
Spatial Arrangement ◽  
Scale Model ◽  
Layer By Layer ◽  
Canny Operator ◽  
Edge Information ◽  
Scale Feature ◽  
Multi Scale ◽  
Rate Improvement

HOG Feature is an efficient edge information descriptor, but it ignores the spatial arrangement of local FER features. In this respect, this paper puts forward a spatial multi-scale model based on an improved HOG algorithm which uses canny operator instead of traditional gradient operator. After the image is divided into a series of sub-regions layer by layer, the histogram of orient gradients for each sub-region is calculated and connected in sequence to obtain the spatial multi-scale HOG feature of whole image. Compared with traditional HOG and the improved PHOG, the proposed SMS_HOG algorithm acquires 5% recognition rate improvement and 50% processing time reduction.

scholarly journals Occipital white matter tracts in human and macaque

2016 ◽  
Author(s):  
Hiromasa Takemura ◽  
Franco Pestilli ◽  
Kevin S. Weiner ◽  
Georgios A. Keliris ◽  
Sofia M. Landi ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Mri ◽  
Occipital Lobe ◽  
Spatial Arrangement ◽  
Information And Communications Technology ◽  
White Matter Tracts ◽  
Contact Information ◽  
Inferior Longitudinal Fasciculus ◽  
Posterior Direction ◽  
Anterior Posterior

AbstractWe compare the major white matter tracts in human and macaque occipital lobe using diffusion MRI. The comparison suggests similarities but also significant differences in spatial arrangement and relative sizes of the tracts. There are several apparently homologous tracts in the two species, including the vertical occipital fasciculus (VOF), optic radiation, forceps major, and inferior longitudinal fasciculus (ILF). There is one large human tract, the inferior fronto-occipital fasciculus, with no corresponding fasciculus in macaque. The macaque VOF is compact and its fibers intertwine with the dorsal segment of the ILF, but the human VOF is much more elongated in the anterior-posterior direction and may be lateral to the ILF. These similarities and differences will be useful in establishing which circuitry in the macaque can serve as an accurate model for human visual cortex.Contact informationHiromasa Takemura, Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Japan [email protected] contributionDesigned the study: HT FP BAW. Performed the experiments. HT FP GAK SML JS FQY DAL WAF NKL. Analyzed the data. HT FP KSW MAB BAW. Contributed analysis tools. FP KSW MAB. Wrote the paper. HT FP KSW BAW.

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