scholarly journals Coupling structure and function in early MS: How a less diverse repertoire of brain function could lead to clinical progression

2021 ◽  
Vol 27 (4) ◽  
pp. 491-493
Author(s):  
Maureen van Dam ◽  
Hanneke E Hulst ◽  
Menno M Schoonheim
Author(s):  
Francois P. Retief ◽  
Louise Cilliers

In Ancient Egypt mummification was associated with extensive organ resection, but the brain was removed through a hole cut in the ethnocide bone. It was thus not observed as an organ. Greek writers of the 6th and 5th centuries BC originally said the brain was the seat of intelligence, the organ of sensory perception and partially the origin of sperm. The substance pneuma, originating from fresh air, played an essential role in brain function. Hippocrates initially described the brain as a double organ, covered by meninges and responsible for perception. Contemporaries like Plato, Aristotle and Diocles confirmed the findings though the latter two considered the heart to be the centre of intelligence. During the late 4th century BC, with the onset of the Hellenistic era of medicine, dissection of the human body was temporarily allowed at the medical school of Alexandria, and this led to a remarkable advance in the understanding of human anatomy and physiology under Herophilus and Erasistratus. Their excellent descriptions of the structure and function of the brain was only matched and surpassed by Galen in the 2nd century AD.


Author(s):  
John Parrington

This book draws on the latest research on the human brain to show how it differs strikingly from those of other animals in its structure and function at molecular and cellular level. It argues that this ‘shift’, enlarging the brain, giving it greater flexibility and enabling higher functions such as imagination, was driven by tool use, but especially by the development of one remarkable tool—language. The complex social interaction brought by language opened up the possibility of shared conceptual worlds, enriched with rhythmic sounds and images that could be drawn on cave walls. This transformation enabled modern humans to generate an exceptional human consciousness, a sense of self that arises as a product of our brain biology and the social interactions we experience. Linking early work by the Russian psychologist Lev Vygotsky to the findings of modern neuroscience, the book also explores how language, culture, and society mediate brain function, and what this view of the human mind may bring to our understanding and treatment of mental illness.


2018 ◽  
Vol 49 (4) ◽  
pp. 798-809 ◽  
Author(s):  
Anila M. D'Mello ◽  
John D. E. Gabrieli

Purpose This review summarizes what is known about the structural and functional brain bases of dyslexia. Method We review the current literature on structural and functional brain differences in dyslexia. This includes evidence about differences in gray matter anatomy, white matter connectivity, and functional activations in response to print and language. We also summarize findings concerning brain plasticity in response to interventions. Results We highlight evidence relating brain function and structure to instructional issues such as diagnosis and prognosis. We also highlight evidence about brain differences in early childhood, before formal reading instruction in school, which supports the importance of early identification and intervention. Conclusion Neuroimaging studies of dyslexia reveal how the disorder is related to differences in structure and function in multiple neural circuits.


Author(s):  
Peter Sterling

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.


Author(s):  
K.E. Krizan ◽  
J.E. Laffoon ◽  
M.J. Buckley

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.


Author(s):  
Robert L. Ochs

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.


Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins

Correlations between structure and function of biological macromolecules have been studied intensively for many years, mostly by indirect methods. High resolution electron microscopy is a unique tool which can provide such information directly by comparing the conformation of biopolymers in their biologically active and inactive state. We have correlated the structure and function of ribosomes, ribonucleoprotein particles which are the site of protein biosynthesis. 70S E. coli ribosomes, used in this experiment, are composed of two subunits - large (50S) and small (30S). The large subunit consists of 34 proteins and two different ribonucleic acid molecules. The small subunit contains 21 proteins and one RNA molecule. All proteins (with the exception of L7 and L12) are present in one copy per ribosome.This study deals with the changes in the fine structure of E. coli ribosomes depleted of proteins L7 and L12. These proteins are unique in many aspects.


2011 ◽  
Vol 21 (3) ◽  
pp. 112-117 ◽  
Author(s):  
Elizabeth Erickson-Levendoski ◽  
Mahalakshmi Sivasankar

The epithelium plays a critical role in the maintenance of laryngeal health. This is evident in that laryngeal disease may result when the integrity of the epithelium is compromised by insults such as laryngopharyngeal reflux. In this article, we will review the structure and function of the laryngeal epithelium and summarize the impact of laryngopharyngeal reflux on the epithelium. Research investigating the ramifications of reflux on the epithelium has improved our understanding of laryngeal disease associated with laryngopharyngeal reflux. It further highlights the need for continued research on the laryngeal epithelium in health and disease.


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