Basic neuroanatomy review

2020 ◽  
pp. 51-66
Author(s):  
John Hart Jr
Keyword(s):  
White Matter ◽  
Basal Ganglia ◽  
Human Brain ◽  
Conceptual Framework ◽  
Limbic System ◽  
Three Dimensional ◽  
System A ◽  
Subcortical Nuclei ◽  
The Brain

Knowledge of basic neuroanatomic organization is essential to understanding cognitive anatomic correlations. This chapter provides a descriptive overview of the basic neuroanatomic structures in the human brain, with a particular emphasis on the structures that are associated with cognitive and behavioural functions. These structures include the lobes of the brain (frontal, parietal, occipital, and temporal), the subcortical nuclei (basal ganglia and thalamus), the white matter, and the limbic system. A conceptual framework is presented that can be utilized to organize the anatomical locations, as well as the interconnections between regions. It is noted that neuroanatomy is not easily learnt by reading a text because it is a three-dimensional set of relationships.

scholarly journals Complex Activity and Short-term Memories in Reciprocally Connected Cerebral Organoids

2021 ◽  
Author(s):  
Tatsuya Osaki ◽  
Yoshiho Ikeuchi
Keyword(s):  
Human Brain ◽  
Three Dimensional ◽  
Oscillatory Activity ◽  
Cellular Functions ◽  
Complex Activity ◽  
Axonal Connections ◽  
Brain Organoid ◽  
External Stimuli ◽  
The Brain

AbstractMacroscopic axonal connections in the human brain distribute information and neuronal activity across the brain. Although this complexity previously hindered elucidation of functional connectivity mechanisms, brain organoid technologies have recently provided novel avenues to investigate human brain function by constructing small segments of the brain in vitro. Here, we describe the neural activity of human cerebral organoids reciprocally connected by a bundle of axons. Compared to conventional organoids, connected organoids produced significantly more intense and complex oscillatory activity. Optogenetic manipulations revealed that the connected organoids could re-play and recapitulate over time temporal patterns found in external stimuli, indicating that the connected organoids were able to form and retain temporal memories. Our findings suggest that connected organoids may serve as powerful tools for investigating the roles of macroscopic circuits in the human brain – allowing researchers to dissect cellular functions in three-dimensional in vitro nervous system models in unprecedented ways.

On the microstructural origin of brain white matter hydraulic permeability

2021 ◽  
Vol 118 (36) ◽  
pp. e2105328118
Author(s):  
Marco Vidotto ◽  
Andrea Bernardini ◽  
Marco Trovatelli ◽  
Elena De Momi ◽  
Daniele Dini
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Drug Transport ◽  
Three Dimensional ◽  
Principal Component ◽  
Hydraulic Permeability ◽  
Convection Enhanced Delivery ◽  
Brain White Matter ◽  
Significant Difference ◽  
The Brain

Brain microstructure plays a key role in driving the transport of drug molecules directly administered to the brain tissue, as in Convection-Enhanced Delivery procedures. The proposed research analyzes the hydraulic permeability of two white matter (WM) areas (corpus callosum and fornix) whose three-dimensional microstructure was reconstructed starting from the acquisition of electron microscopy images. We cut the two volumes with 20 equally spaced planes distributed along two perpendicular directions, and, on each plane, we computed the corresponding permeability vector. Then, we considered that the WM structure is mainly composed of elongated and parallel axons, and, using a principal component analysis, we defined two principal directions, parallel and perpendicular, with respect to the axons’ main direction. The latter were used to define a reference frame onto which the permeability vectors were projected to finally obtain the permeability along the parallel and perpendicular directions. The results show a statistically significant difference between parallel and perpendicular permeability, with a ratio of about two in both the WM structures analyzed, thus demonstrating their anisotropic behavior. Moreover, we find a significant difference between permeability in corpus callosum and fornix, which suggests that the WM heterogeneity should also be considered when modeling drug transport in the brain. Our findings, which demonstrate and quantify the anisotropic and heterogeneous character of the WM, represent a fundamental contribution not only for drug-delivery modeling, but also for shedding light on the interstitial transport mechanisms in the extracellular space.

The history and scope of neuropsychiatry

2020 ◽  
pp. 3-12
Author(s):  
Michael Trimble
Keyword(s):  
Twentieth Century ◽  
Nervous System ◽  
Human Brain ◽  
Limbic System ◽  
Historical Development ◽  
The Body ◽  
The Enlightenment ◽  
Romantic Era ◽  
The Brain

This chapter discusses the clinical necessity from which the intersection of neurology and psychiatry arose, exploring different eras and their associated intellectual milestones in order to understand the historical framework of contemporary neuropsychiatry. Identifying Hippocrates’ original acknowledgement of the relation of the human brain to epilepsy as a start point, the historical development of the field is traced. This encompasses Thomas Willis and his nascent descriptions of the limbic system, the philosophical and alchemical strides of the Enlightenment, and the motivations behind the Romantic era attempts to understand the brain. It then follows the growth of the field through the turn of the twentieth century, in spite of the prominence of psychoanalysis and the idea of the brainless mind, and finally the understanding of the ‘integrated action’ of the body and nervous system, which led to the integration of psychiatry and neurology, allowing for the first neuropsychiatric examinations of epilepsy.

MR Imaging in Solvent-Induced Chronic Toxic Encephalopathy

1996 ◽  
Vol 37 (1P1) ◽  
pp. 177-179 ◽  
Author(s):  
K.-Å. Thuomas ◽  
C. Möller ◽  
L. M. Ödkvist ◽  
U. Flodin ◽  
N. Dige
Keyword(s):  
White Matter ◽  
Basal Ganglia ◽  
Spin Echo ◽  
Toxic Encephalopathy ◽  
Fast Spin Echo ◽  
Number Of Patients ◽  
Good Technique ◽  
Chronic Toxic Encephalopathy ◽  
The Brain ◽  
T2 Weighted Images

Purpose: To use MR to examine patients with CNS symptoms indicating chronic intoxication. Material and Methods: Thirty-two subjects exposed to industrial solvents for 5 to 28 years and 40 age-matched, healthy controls were examined. Results: All patients showed decreased signal in the basal ganglia on T2-weighted images. In 11 of the patients the white matter showed diffuse hyperintensity with loss of the grey-white matter discrimination and with distinct periventricular hyperintensities in 5 of the patients. The controls had no pathological changes in the brain. Conclusion: Although the relatively small number of patients may obscure the significance, findings observed on T2-weighted images were patchy periventricular hyperintensities and hypointensities in the basal ganglia. Fast spin-echo is a good technique with fast acquisition of images with true spin-echo contrast features.

Microstructural Hyperelastic Characterization of Brain White Matter in Tension

2019 ◽  
Author(s):  
Mohammadreza Ramzanpour ◽  
Mohammad Hosseini-Farid ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Finite Element ◽  
White Matter ◽  
Human Brain ◽  
Volume Fraction ◽  
Fibrous Composite ◽  
Diffuse Axonal Injury ◽  
Stiffness Ratio ◽  
Fibrous Composite Material ◽  
Brain White Matter ◽  
The Brain

Abstract Axons as microstructural constituent elements of brain white matter are highly oriented in extracellular matrix (ECM) in one direction. Therefore, it is possible to model the human brain white matter as a unidirectional fibrous composite material. A micromechanical finite element model of the brain white matter is developed to indirectly measure the brain white matter constituents’ properties including axon and ECM under tensile loading. Experimental tension test on corona radiata conducted by Budday et al. 2017 [1] is used in this study and one-term Ogden hyperelastic constitutive model is applied to characterize its behavior. By the application of genetic algorithm (GA) as a black box optimization method, the Ogden hyperelastic parameters of axon and ECM minimizing the error between numerical finite element simulation and experimental results are measured. Inverse analysis is conducted on the resultant optimized parameters shows high correlation of coefficient (>99%) between the numerical and experimental data which verifies the accuracy of the optimization procedure. The volume fraction of axons in porcine brain white matter is taken to be 52.7% and the stiffness ratio of axon to ECM is perceived to be 3.0. As these values are not accurately known for human brain white matter, we study the material properties of axon and ECM for different stiffness ratio and axon volume fraction values. The results of this study helps to better understand the micromechanical structure of the brain and micro-level injuries such as diffuse axonal injury.

Three-Dimensional Interactive and Stereotactic Human Brain Atlas of White Matter Tracts

2011 ◽  
Vol 10 (1) ◽  
pp. 33-55 ◽  
Author(s):  
Wieslaw L. Nowinski ◽  
Beng Choon Chua ◽  
Guo Liang Yang ◽  
Guo Yu Qian
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Three Dimensional ◽  
Brain Atlas ◽  
White Matter Tracts

Tractography of White Matter Fibers Using Diffusion MRI

2022 ◽  
pp. 98-112
Author(s):  
Strivathsav Ashwin Ramamoorthy
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Diffusion Mri ◽  
Neural Circuits ◽  
Water Molecules ◽  
Neural Connectivity ◽  
Non Invasive ◽  
Diffusion Weighted Images ◽  
Different Types ◽  
The Brain

To understand more about the human brain and how it works, it is vital to understand how the neural circuits connect different regions of the brain. The human brain is filled predominantly with water and the majority of the water molecules undergo diffusion which can be captured with the help of diffusion MRI. Diffusion weighted images enable us to reconstruct the neural circuits in a non-invasive manner, and this procedure is referred to as tractography. Tractography aids neurosurgeons to understand the neural connectivity of the patient. This chapter attempts to explain the procedure of tractography and different types of algorithms.

scholarly journals Data integration through brain atlasing: Human Brain Project tools and strategies

2018 ◽  
Vol 50 ◽  
pp. 70-76 ◽  
Author(s):  
Ingvild E. Bjerke ◽  
Martin Øvsthus ◽  
Eszter A. Papp ◽  
Sharon C. Yates ◽  
Ludovico Silvestri ◽  
...  
Keyword(s):  
Human Brain ◽  
Three Dimensional ◽  
Anatomical Location ◽  
Data Systems ◽  
Data Types ◽  
Online Data ◽  
Human Brain Project ◽  
Wide Range ◽  
Brain Data ◽  
The Brain

AbstractThe Human Brain Project (HBP), an EU Flagship Initiative, is currently building an infrastructure that will allow integration of large amounts of heterogeneous neuroscience data. The ultimate goal of the project is to develop a unified multi-level understanding of the brain and its diseases, and beyond this to emulate the computational capabilities of the brain. Reference atlases of the brain are one of the key components in this infrastructure. Based on a new generation of three-dimensional (3D) reference atlases, new solutions for analyzing and integrating brain data are being developed. HBP will build services for spatial query and analysis of brain data comparable to current online services for geospatial data. The services will provide interactive access to a wide range of data types that have information about anatomical location tied to them. The 3D volumetric nature of the brain, however, introduces a new level of complexity that requires a range of tools for making use of and interacting with the atlases. With such new tools, neuroscience research groups will be able to connect their data to atlas space, share their data through online data systems, and search and find other relevant data through the same systems. This new approach partly replaces earlier attempts to organize research data based only on a set of semantic terminologies describing the brain and its subdivisions.

scholarly journals Application value of three-dimensional arterial spin labeling perfusion imaging in investigating cerebral blood flow dynamics in normal full-term neonates

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jia-Ning Wang ◽  
Jia Li ◽  
Huai-Jun Liu ◽  
Xiao-Ping Yin ◽  
Huan Zhou ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Basal Ganglia ◽  
Three Dimensional ◽  
Full Term ◽  
Term Neonates ◽  
Corona Radiata ◽  
Frontal White Matter ◽  
Blood Flow Dynamics

Abstract Background This study aims to investigate the application value of three-dimensional arterial spin labeling (3DASL) in investigating cerebral blood flow dynamics in full-term neonates. Methods A total of 60 full-term neonates without known intracranial pathology were recruited for 3DASL examination. These neonates were divided into three groups: 1–3 day group, 4–7 day group, and 8–15 day group. On the cerebral blood flow (CBF) images, regions of interest (ROI) were selected from the frontal white matter, parietal white matter, basal ganglia, corona radiata, thalamus and brainstem, and the CBF values of each ROI were recorded. The CBF values of ROIs at bilaterally symmetric locations, the values of each ROI between males and females, and the values of each ROI among these three different age groups were compared. Results The difference in CBF values of the frontal white matter, parietal white matter, basal ganglia, corona radiata and thalamus at the bilateral symmetric positions were not statistically significant. There was no statistical difference in the CBF values of each brain region between the male and female groups. The CBF values at the basal ganglia region, corona radiata and parietal white matter were higher in the 8–15 day group, when compared to the 1–3 day and 4–7 day groups (P < 0.05). The CBF value at the basal ganglia region was higher in the 4–7 day group, when compared to the 1–3 day group (P < 0.05). The CBF value at the frontal white matter was lower in the 4–7 day group, when compared to the 1–3 day and 8–15 day group (P < 0.05). The CBF value at the brainstem was higher in the 4–7 day group, when compared to the 1–3 day and 8–15 day groups (P < 0.05). Conclusion The 3DASL can quantitatively measure CBF, and be used to evaluate cerebral hemodynamics in neonates. The basal ganglia region and corona radiata CBF increases with the increase in neonatal diurnal age.

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