Cortical Cartography

Biofeedback ◽  
2010 ◽  
Vol 38 (1) ◽  
pp. 9-12 ◽  
Author(s):  
David A. Kaiser

Abstract Architecture is one part science, one part craft, and two parts art.—David Rutten This article describes the investigation of structural-functional associations in the brain. Using light microscopy in 1909, Brodmann divided the human and primate brains into dozens of areas based on cell types and distributions, which has since been supplemented by a 3-dimensional coordinate system, an xyz system of millimeter distances. A number of electroencephalograph tomographic (volume) solutions exist, and this article explains the Brodmann montage developed by the author using the spherical harmonic expansion solution by Pascual-Marqui. The author describes his approach to training specific Brodmann areas with electroencephalograhic operant conditioning or feedback.

1980 ◽  
Vol 58 (10) ◽  
pp. 1735-1740 ◽  
Author(s):  
Kathryn Bell ◽  
Joan R. Marsden

The supraoesophageal ganglion of Nereis virens has been surveyed by light microscopy to determine the locations of probable neurosecretory cells. Neurons reacting with paraldehyde fuchsin are found scattered throughout the brain, but the majority are accumulated posteriorly in nucleus 20. This nucleus was examined in some detail, and the histology of four cell types is described. Two types (p and r) are strongly paraldehyde-fuchsin-positive, and may be secretory. On the basis of other staining characteristics, and uptake of labelled cystine, it is concluded that p cells are rich in cystine and (or) cysteine. A comparison of juvenile and adult brains revealed that the same cell types exist at both developmental stages, but that p and r cells increase in number and staining intensity with age. These findings are not consistent with the notion that these particular cells are the source of a "juvenile hormone' ' which has been reported to exist in nereids. Rather it is suggested that the described cells are producers of a maturation and (or) spawning hormone.


Author(s):  
S. Tai

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1468
Author(s):  
Yashika S. Kamte ◽  
Manisha N. Chandwani ◽  
Alexa C. Michaels ◽  
Lauren A. O’Donnell

Viruses that infect the central nervous system (CNS) are associated with developmental abnormalities as well as neuropsychiatric and degenerative conditions. Many of these viruses such as Zika virus (ZIKV), cytomegalovirus (CMV), and herpes simplex virus (HSV) demonstrate tropism for neural stem cells (NSCs). NSCs are the multipotent progenitor cells of the brain that have the ability to form neurons, astrocytes, and oligodendrocytes. Viral infections often alter the function of NSCs, with profound impacts on the growth and repair of the brain. There are a wide spectrum of effects on NSCs, which differ by the type of virus, the model system, the cell types studied, and the age of the host. Thus, it is a challenge to predict and define the consequences of interactions between viruses and NSCs. The purpose of this review is to dissect the mechanisms by which viruses can affect survival, proliferation, and differentiation of NSCs. This review also sheds light on the contribution of key antiviral cytokines in the impairment of NSC activity during a viral infection, revealing a complex interplay between NSCs, viruses, and the immune system.


Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 325
Author(s):  
Petra Korać ◽  
Mariastefania Antica ◽  
Maja Matulić

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.


2021 ◽  
Vol 10 (11) ◽  
pp. 2358
Author(s):  
Maria Grazia Giovannini ◽  
Daniele Lana ◽  
Chiara Traini ◽  
Maria Giuliana Vannucchi

The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. In the present review will be described the modalities through which the microbiota and gut control each other, and the main microbiota products conditioning both local and brain homeostasis. Much evidence has accumulated over the past decade in favor of a significant association between dysbiosis, neuroinflammation and neurodegeneration. Presently, the pathogenetic mechanisms triggered by molecules produced by the altered microbiota, also responsible for the onset and evolution of Alzheimer disease, will be described. Our attention will be focused on the role of astrocytes and microglia. Numerous studies have progressively demonstrated how these glial cells are important to ensure an adequate environment for neuronal activity in healthy conditions. Furthermore, it is becoming evident how both cell types can mediate the onset of neuroinflammation and lead to neurodegeneration when subjected to pathological stimuli. Based on this information, the role of the major microbiota products in shifting the activation profiles of astrocytes and microglia from a healthy to a diseased state will be discussed, focusing on Alzheimer disease pathogenesis.


2021 ◽  
Vol 22 (11) ◽  
pp. 5818
Author(s):  
Gaylia Jean Harry

A change in microglia structure, signaling, or function is commonly associated with neurodegeneration. This is evident in the patient population, animal models, and targeted in vitro assays. While there is a clear association, it is not evident that microglia serve as an initiator of neurodegeneration. Rather, the dynamics imply a close interaction between the various cell types and structures in the brain that orchestrate the injury and repair responses. Communication between microglia and neurons contributes to the physiological phenotype of microglia maintaining cells in a surveillance state and allows the cells to respond to events occurring in their environment. Interactions between microglia and astrocytes is not as well characterized, nor are interactions with other members of the neurovascular unit; however, given the influence of systemic factors on neuroinflammation and disease progression, such interactions likely represent significant contributes to any neurodegenerative process. In addition, they offer multiple target sites/processes by which environmental exposures could contribute to neurodegenerative disease. Thus, microglia at least play a role as a significant other with an equal partnership; however, claiming a role as an initiator of neurodegeneration remains somewhat controversial.


Sign in / Sign up

Export Citation Format

Share Document