scholarly journals A combined pipeline for quantitative analysis of human brain cytoarchitecture

Author(s):  
Irene Costantini ◽  
Giacomo Mazzamuto ◽  
Matteo Roffilli ◽  
Annunziatina Laurino ◽  
Filippo Maria Castelli ◽  
...  

AbstractThe 3D analysis of the human brain architecture at cellular resolution is still a big challenge. In this work, we propose a pipeline that solves the problem of performing neuronal mapping in large human brain samples at micrometer resolution. First, we introduce the SWITCH/TDE protocol: a robust methodology to clear and label human brain tissue. Then, we implement the 2.5D method based on a Convolutional Neural Network, to automatically detect and segment all neurons. Our method proved to be highly versatile and was applied successfully on specimens from different areas of the cortex originating from different subjects (young, adult and elderly, both healthy and pathological). We quantitatively evaluate the density and, more importantly, the mean volume of the thousands of neurons identified within the specimens. In conclusion, our pipeline makes it possible to study the structural organization of the brain and expands the histopathological studies to the third dimension.

2019 ◽  
Vol 21 (Supplement_4) ◽  
pp. iv16-iv16
Author(s):  
Alastair Kirby ◽  
Jose Pedro Lavrador ◽  
Christian Brogna ◽  
Francesco Vergani ◽  
Bassel Zebian ◽  
...  

Abstract Gliomas often present clinically with seizures. Tumour-associated seizures can be difficult to control with medication. A deeper understanding of the cellular mechanisms underlying tumour-associated seizures would provide a basis for developing new treatments. Here, we investigate epileptic discharges in peritumoral cortex using living human brain tissue donated by people having a craniotomy for glioma resection (REC approval, 18/SW/002). The brain tissue was cut into thin slices, which preserved the architecture of the glioma and the adjacent healthy brain. The brain slices were incubated in 5-aminolevulinic acid to make the glioma cells fluorescent. This enabled us to make electrophysiological recordings of brain activity across the boundary between glioma and brain. We recorded from brain slices of 5 participants with glioblastoma and 4 participants with oligodendroglioma (WHO grade II – III). Spontaneous “seizure-like” discharges were recorded in brain slices from 5/8 participants (3 GBM, 2 oligodendroglioma) who reported seizures and from one participant (GBM) who had not had any clinical seizures. Further analysis of the seizure-like discharges revealed that they could be subdivided into two distinct types based on the major frequencies in the discharge. We concluded that human brain slices from people with either a low-grade or a high-grade glioma can generate spontaneous seizure-like discharges. The living human brain tissue preparation gives us a platform to study the mechanisms of tumour-associated seizures and how abnormal neural activity affects glioma growth.


1972 ◽  
Vol 34 (3) ◽  
pp. 799-806 ◽  
Author(s):  
John C. Baird ◽  
Virgil Graf ◽  
Richard Degerman

Results are presented from a new method to determine a person's conception of complex stimuli. In three related experiments Ss expressed their views of ideal organisms by distributing a fixed resource among hypothetical properties of the ideal. The results from the experiments were highly correlated, lending weight to the reliability and generality of the approach. Cluster analysis and multidimensional scaling were used to group the properties in two dimensions, while the mean amount allocated to a property was represented in the third dimension. A three-dimensional plot was constructed for each of four ideals: the only organism on earth, a member of the only species on earth, an organism going into outer space, and an organism coming to earth from outer space.


Author(s):  
Kohei Shiota

Abstract In this paper, the process of CNS development in human embryos and fetuses is described. The primordium of the nervous system appears as early as during the third week after fertilization, but its differentiation and maturation require a considerably long period of time until after birth. Therefore, the developing brain is vulnerable to various kinds of deleterious environmental effects during the preand perinatal life. This paper aims at giving an overview of the major organogenesis of the brain in human embryos and fetuses.


2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii54-iii54
Author(s):  
A J Kirby ◽  
J P Lavrador ◽  
C Brogna ◽  
F Vergani ◽  
C Chandler ◽  
...  

Abstract BACKGROUND Invading glioma cells affect the physiological function of the peritumoural cortex. This may manifest clinically as seizures. Here, we investigate the effect the invading glioma cells on the electrophysiological signalling of the peritumoral cortex using living human brain tissue donated by people having a craniotomy for glioma resection (REC approval, 18/SW/002). MATERIAL AND METHODS The brain tissue was cut into thin slices, which preserved the architecture of the glioma and the adjacent healthy brain. The brain slices were incubated in 5-aminolevulinic acid to make the glioma cells fluorescent. We observed 5-ALA induced fluorescence in both low-grade and high-grade gliomas. This enabled us to make electrophysiological recordings of brain activity across the boundary between glioma and brain. RESULTS We recorded from brain slices of 5 participants with glioblastoma and 4 participants with oligodendroglioma (WHO grade II - III). Spontaneous “seizure-like” discharges were recorded in brain slices from 5/8 participants (3 GBM, 2 oligodendroglioma) who reported seizures and from one participant (GBM) who had not had any clinical seizures. Further analysis of the electrical discharges revealed that they could be subdivided into two distinct types based on the major frequencies in the discharge. CONCLUSION We concluded that human brain slices from people with either a low-grade or a high-grade glioma can generate spontaneous seizure-like discharges. This electrophysiological signature will be compared to infiltration and grade of the glioma cells in the donated sample. The living human brain tissue preparation gives us a platform to study the mechanisms of tumour-associated seizures and how abnormal neural activity affects glioma growth.


Perception ◽  
1987 ◽  
Vol 16 (6) ◽  
pp. 785-818 ◽  
Author(s):  
Nicholas J Wade

It was not until 1838, when Wheatstone published his account of the stereoscope, that stereoscopic depth perception entered into the body of binocular phenomena. It is argued that the stereoscope was not invented earlier because the phenomenon of stereopsis based on disparity had not been adequately described. This was the case despite the fact that there had been earlier descriptions of tasks that could be performed better with two eyes than with one; the perceptual deficits attendant upon the loss of one eye had been remarked upon; analyses of the projections to each eye were commonplace, and binocular disparities were accurately illustrated; moreover, binocular microscopes and telescopes had been made over a century earlier. Theories of binocular vision were generally confined to accounting for singleness of vision with two eyes, and the concepts employed to account for this were visible direction, corresponding retinal points, and union in the brain. The application of these concepts inhibited any consideration of disparities, other than for yielding diplopia. When perception of the third dimension was addressed by Berkeley at the beginning of the eighteenth century, it was in the context of monocular vision and binocular convergence. Thereafter visual direction became the province for binocular vision and it was analysed in terms of geometrical optics, whereas visual distance was examined in the context of learned associations between vision and touch. This artificial division was challenged initially with respect to visual direction and later with respect to stereopsis. An additional factor delaying the invention of the stereoscope was that experiments on binocular vision generally involved abnormal convergence on extended objects. Wheatstone's accidental observation of stereopsis was under artificial conditions in which disparity alone defined the binocular depth perceived. Once invented the stereoscope was enthusiastically embraced by students of vision. It is suggested that the ease with which retinal disparity could be manipulated in stereopairs has led to an exaggeration of its importance in space perception.


Author(s):  
Georgia Kouroupi ◽  
Kanella Prodromidou ◽  
Florentia Papastefanaki ◽  
Era Taoufik ◽  
Rebecca Matsas

Stem cell technologies have opened up new avenues in the study of human biology and disease. Especially, the advent of human embryonic stem cells followed by reprograming technologies for generation of induced pluripotent stem cells have instigated studies for modeling human brain development and disease by providing a means to simulate a human tissue with otherwise limited or no accessibility to researchers. Brain development is a complex process achieved in a remarkably controlled spatial and temporal manner through coordinated cellular and molecular events. In vitro models aim to mimic these processes and recapitulate brain organogenesis. Initially, two-dimensional neural cultures presented an innovative landmark for investigating human neuronal and, more recently, glial biology as well as for modeling brain neurodevelopmental and neurodegenerative diseases. The establishment of three-dimensional cultures in the form of brain organoids was an equally important milestone in the field. Brain organoids mimic more closely the in vivo tissue composition and architecture and are more physiologically relevant than monolayer cultures. They therefore represent a more realistic cellular environment for modeling the cell biology and pathology of the nervous system. Here we highlight the journey to recapitulate human brain development and disease in-a-dish, starting from two-dimensional in vitro systems up to the third dimension provided by brain organoids. We discuss the potential of these approaches for modeling human brain development and evolution and their promise for understanding and treating brain disease.


Author(s):  
E. Muñumer Herrero ◽  
C. Ellul ◽  
J. Morley

<p><strong>Abstract.</strong> Popularity and diverse use of 3D city models has increased exponentially in the past few years, providing a more realistic impression and understanding of cities. Often, 3D city models are created by elevating the buildings from a detailed 2D topographic base map and subsequently used in studies such as solar panel allocation, infrastructure remodelling, antenna installations or even tourist guide applications. However, the large amount of resulting data slows down rendering and visualisation of the 3D models, and can also impact the performance of any analysis. Generalisation enables a reduction in the amount of data – however the addition of the third dimension makes this process more complex, and the loss of detail resulting from the process will inevitably have an impact on the result of any subsequent analysis.</p><p>While a few 3D generalization algorithms do exist in a research context, these are not available commercially. However, GIS users can create the generalised 3D models by simplifying and aggregating the 2D dataset first and then extruding it to the third dimension. This approach offers a rapid generalization process to create a dataset to underpin the impact of using generalised data for analysis. Specifically, in this study, the line of sight from a tall building and the sun shadow that it creates are calculated and compared, in both original and generalised datasets. The results obtained after the generalisation process are significant: both the number of polygons and the number of nodes are minimized by around 83<span class="thinspace"></span>% and the volume of 3D buildings is reduced by 14.87<span class="thinspace"></span>%. As expected, the spatial analyses processing times are also reduced. The study demonstrates the impact of generalisation on analytical results – which is particularly relevant in situations where detailed data is not available and will help to guide the development of future 3D generalisation algorithms. It also highlights some issues with the overall maturity of 3D analysis tools, which could be one factor limiting uptake of 3D GIS.</p>


Author(s):  
شاهر يوسف ياغي

This study aimed to identify the extent iPad’s contributed to enhance inclusion of students with visual impairment (partially) in public schools. The study used the descriptive and analytical approach. The population consisted of (160) students who received iPad device within the “vision project” implemented at UNRWA schools in Gaza strip. The study used a questionnaire prepared and adapted by the researcher, to measure degree of iPad’s contribution to inclusion in general and at three dimensions: academic, psychological, and behavioral. Results showed the level of iPad’s contribution to enhance inclusion among students with visual impairment was high, with an average of 2.70 and a relative weight 90%. Concerning the three dimensions, results showed the academic attained as average of 2.77 with relative weight 88.6%, however in the second dimension (psychological) the mean was 2.98 with relative weight 99.3%, lastly for the third dimension (behavioral), the mean was 2.67 with relative weight 89.0%. This indicated high level of iPad’s contribution to enhance inclusion of students with visual impairment at public schools specifically at UNRWA schools. The study recommended use iPads for best inclusive practices.


2020 ◽  
Vol 9 (37) ◽  
Author(s):  
Simona Kraberger ◽  
Diego Mastroeni ◽  
Elaine Delvaux ◽  
Arvind Varsani

ABSTRACT Complete genome sequences of two novel torque teno viruses (TTVs) were identified in human brain tissue. These sequences are 3,245 nucleotides (nt) and 2,900 nt long and share 68% and 72% open reading frame 1 (ORF1) identity, respectively, with other human TTVs. This report extends the identification of TTV sequences in the brain.


1997 ◽  
Vol 20 (4) ◽  
pp. 575-575
Author(s):  
Arnold B. Scheibel

We suggest that neither selectionism nor constructivism alone are responsible for learning-based changes in the brain. On the basis of quantitative structural studies of human brain tissue it has been possible to find evidence of both increase and decrease in tissue mass at synaptic and dendritic levels. It would appear that both processes are involved in the course of learning-dependent changes.


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