scholarly journals Illustrating cerebral function: the iconography of arrows

2000 ◽  
Vol 355 (1404) ◽  
pp. 1789-1799 ◽  
Author(s):  
G. D. Schott
Keyword(s):  
Essential Feature ◽  
Structural Data ◽  
Neural Function ◽  
Cerebral Function ◽  
Free Standing ◽  
Brain Topography ◽  
Directional Characteristic ◽  
Anatomical Structures ◽  
Graphic Device ◽  
The Brain

For over a century the arrow has appeared in illustrations of cerebral function, yet the implications of using such symbols have not been previously considered. This review seeks to outline the nature, evolution, applications and limitations of this deceptively simple graphic device when it is used to picture functions of the brain. The arrow is found to have been used in several different ways: as a means of endowing anatomical structures with functional properties; as a method of displaying neural function either in free–standing form or in a structural or spatial framework; as a device for correlating functional data with underlying brain topography; and as a technique for linking functions of the brain with the world outside and with various philosophical concepts. For many of these uses the essential feature of the arrow is its directional characteristic. In contrast to the line, it is direction that enables the arrow to display information about time, which in turn can be exploited to depict functional rather than structural data. However, the use of the arrow is fraught with difficulties. It is often unclear whether an arrow has been used to illustrate fact, hypothesis, impression or possibility, or merely to provide a decorative flourish. Furthermore, the powerful symbolic nature of the arrow can so easily confer a spurious validity on the conjectural. Increasingly now there are insuperable difficulties when attempting to illustrate complex mechanisms of brain function. In the iconography of cerebral function, therefore, arrows with all their ambiguities may in certain circumstances become superseded by more non–representational symbols such as the abstract devices of the computational neuroscientist.

scholarly journals Effect of Xenon Treatment on Gene Expression in Brain Tissue after Traumatic Brain Injury in Rats

2021 ◽  
Vol 11 (7) ◽  
pp. 889
Author(s):  
Anton D. Filev ◽  
Denis N. Silachev ◽  
Ivan A. Ryzhkov ◽  
Konstantin N. Lapin ◽  
Anastasiya S. Babkina ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Brain Tissue ◽  
Target Genes ◽  
Neural Function ◽  
Stress Genes ◽  
Expression Of Genes ◽  
Delayed Recovery ◽  
The Brain ◽  
Lower Expression

The overactivation of inflammatory pathways and/or a deficiency of neuroplasticity may result in the delayed recovery of neural function in traumatic brain injury (TBI). A promising approach to protecting the brain tissue in TBI is xenon (Xe) treatment. However, xenon’s mechanisms of action remain poorly clarified. In this study, the early-onset expression of 91 target genes was investigated in the damaged and in the contralateral brain areas (sensorimotor cortex region) 6 and 24 h after injury in a TBI rat model. The expression of genes involved in inflammation, oxidation, antioxidation, neurogenesis and neuroplasticity, apoptosis, DNA repair, autophagy, and mitophagy was assessed. The animals inhaled a gas mixture containing xenon and oxygen (ϕXe = 70%; ϕO2 25–30% 60 min) 15–30 min after TBI. The data showed that, in the contralateral area, xenon treatment induced the expression of stress genes (Irf1, Hmox1, S100A8, and S100A9). In the damaged area, a trend towards lower expression of the inflammatory gene Irf1 was observed. Thus, our results suggest that xenon exerts a mild stressor effect in healthy brain tissue and has a tendency to decrease the inflammation following damage, which might contribute to reducing the damage and activating the early compensatory processes in the brain post-TBI.

scholarly journals Culture Wires the Brain

2010 ◽  
Vol 5 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Denise C. Park ◽  
Chih-Mao Huang
Keyword(s):  
Brain Structure ◽  
Cultural Psychology ◽  
Structure And Function ◽  
Neural Function ◽  
Limited Evidence ◽  
Neural Structure ◽  
Cultural Experiences ◽  
Brain Structure And Function ◽  
And Function ◽  
The Brain

There is clear evidence that sustained experiences may affect both brain structure and function. Thus, it is quite reasonable to posit that sustained exposure to a set of cultural experiences and behavioral practices will affect neural structure and function. The burgeoning field of cultural psychology has often demonstrated the subtle differences in the way individuals process information—differences that appear to be a product of cultural experiences. We review evidence that the collectivistic and individualistic biases of East Asian and Western cultures, respectively, affect neural structure and function. We conclude that there is limited evidence that cultural experiences affect brain structure and considerably more evidence that neural function is affected by culture, particularly activations in ventral visual cortex—areas associated with perceptual processing.

scholarly journals Remote control of neural function by X-ray-induced scintillation

2019 ◽  
Author(s):  
Takanori Matsubara ◽  
Takayuki Yanagida ◽  
Noriaki Kawaguchi ◽  
Takashi Nakano ◽  
Junichiro Yoshimoto ◽  
...  
Keyword(s):  
Dopamine Neurons ◽  
Neural Function ◽  
X Rays ◽  
Cellular Functions ◽  
X Ray ◽  
Functional Studies ◽  
Clinical Dose ◽  
Visible Luminescence ◽  
Midbrain Dopamine ◽  
The Brain

Scintillators emit visible luminescence when irradiated with X-rays. Given the unlimited tissue penetration of X-rays, the employment of scintillators could enable remote optogenetic control of neural functions at any depth of the brain. Here we show that a yellow-emitting inorganic scintillator, Ce-doped Gd3(Al,Ga)5O12 (Ce:GAGG), could effectively activate red-shifted excitatory and inhibitory opsins, ChRmine and GtACR1, respectively. Using injectable Ce:GAGG microparticles, we successfully activated and inhibited midbrain dopamine neurons in freely moving mice by X-ray irradiation, producing bidirectional modulation of place preference behavior. Ce:GAGG microparticles were non-cytotoxic and biocompatible, allowing for chronic implantation. Pulsed X-ray irradiation at a clinical dose level was sufficient to elicit behavioral changes without reducing the number of radiosensitive cells in the brain and bone marrow. Thus, scintillator-mediated optogenetics enables less invasive, wireless control of cellular functions at any tissue depth in living animals, expanding X-ray applications to functional studies of biology and medicine.

Summing Up

2019 ◽  
pp. 145-158
Author(s):  
Dale Purves
Keyword(s):  
Nervous System ◽  
Cardiovascular System ◽  
Digestive System ◽  
Neural Function ◽  
Empirical Basis ◽  
Organ Systems ◽  
The World ◽  
Survival And Reproduction ◽  
Successful Behavior ◽  
The Brain

A major challenge in neuroscience today is to decipher the operating principle of the brain and the rest of the nervous system in the same straightforward way that biologists have come to understand the functions of other organs and organ systems (e.g., the cardiovascular system, the digestive system, and so on). The argument here has been that the function of nervous systems is to make, maintain, and modify neural associations that ultimately promote survival and reproduction in a world that sensory systems can’t apprehend. In this way, we and other animals can link the subjective domain of perception to successful behavior without ever recovering the properties of the world. Neural function on a wholly empirical basis may be the key to understanding how brains operate.

Surgical management of cerebellopontine angle and petrous lesions

2019 ◽  
pp. 281-296
Author(s):  
Nicholas Hall ◽  
Yuval Sufaro ◽  
Andrew Kaye
Keyword(s):  
Skull Base ◽  
Cerebellopontine Angle ◽  
Surgical Techniques ◽  
Operating Microscope ◽  
Critical Function ◽  
Anatomical Structures ◽  
Nerve Monitoring ◽  
Mortality And Morbidity ◽  
Harvey Cushing ◽  
The Brain

At the turn of the twentieth century Harvey Cushing, the father of neurosurgery, described the cerebellopontine angle (CPA) region of the brain as ‘the gloomy corner of neurosurgery’, famously comparing this anatomical region with the bloody fence corner of the Gettysburg. With limited magnification and illumination, a modern skull base subspecialist neurosurgeon can understand the huge technical challenges that pioneers such as Cushing would have faced treating large tumours with major pre-existing morbidity in this location. At that stage Cushing advocated subtotal tumour debulking as the only rational strategy, however, shortly after that Dandy began to advocate safe total removal of cerebellopontine angle tumours. Since these early days introduction of more sophisticated anaesthesia, perioperative antibiotic prophylaxis, the operating microscope, and cranial nerve monitoring techniques have all resulted in significant advances in cerebellopontine angle surgery. The concentration of cases in subspecialty centres and the recognition of the importance of experience and meticulous technique has transformed skull base surgery into a subspecialty field with consequent reductions in mortality and morbidity. Although fragile and tenuous anatomical structures, supplying critical function, will always make treatment of pathology in this region a high-risk challenge, frequently, curative outcomes are now achieved with minimal morbidity for patients. This chapter aims to outline the anatomy and pathology of the cerebellopontine angle. The chapter describes the presentation of patients and investigations needed to make diagnoses for the different pathologies in this region, and the surgical techniques, approaches, and outcomes that we use to treat these lesions.

scholarly journals Influence of Patient-Specific Head Modeling on EEG Source Imaging

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yohan Céspedes-Villar ◽  
Juan David Martinez-Vargas ◽  
G. Castellanos-Dominguez
Keyword(s):  
Neurological Diseases ◽  
Structural Data ◽  
Problem Formulation ◽  
Patient Specific ◽  
Source Imaging ◽  
Eeg Source Imaging ◽  
Deep Sources ◽  
The Individual ◽  
Tissue Compartments ◽  
The Brain

Electromagnetic source imaging (ESI) techniques have become one of the most common alternatives for understanding cognitive processes in the human brain and for guiding possible therapies for neurological diseases. However, ESI accuracy strongly depends on the forward model capabilities to accurately describe the subject’s head anatomy from the available structural data. Attempting to improve the ESI performance, we enhance the brain structure model within the individual-defined forward problem formulation, combining the head geometry complexity of the modeled tissue compartments and the prior knowledge of the brain tissue morphology. We validate the proposed methodology using 25 subjects, from which a set of magnetic-resonance imaging scans is acquired, extracting the anatomical priors and an electroencephalography signal set needed for validating the ESI scenarios. Obtained results confirm that incorporating patient-specific head models enhances the performed accuracy and improves the localization of focal and deep sources.

scholarly journals S-Adenosylmethionine Deficiency and Brain Accumulation of S-Adenosylhomocysteine in Thioacetamide-Induced Acute Liver Failure

Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2135
Author(s):  
Anna Maria Czarnecka ◽  
Wojciech Hilgier ◽  
Magdalena Zielińska
Keyword(s):  
Liver Failure ◽  
Acute Liver Failure ◽  
Redox Homeostasis ◽  
Cerebral Function ◽  
Total Glutathione ◽  
Cellular Redox ◽  
Therapeutic Value ◽  
Transsulfuration Pathway ◽  
Subsequent Hydrolysis ◽  
The Brain

Background: Acute liver failure (ALF) impairs cerebral function and induces hepatic encephalopathy (HE) due to the accumulation of neurotoxic and neuroactive substances in the brain. Cerebral oxidative stress (OS), under control of the glutathione-based defense system, contributes to the HE pathogenesis. Glutathione synthesis is regulated by cysteine synthesized from homocysteine via the transsulfuration pathway present in the brain. The transsulfuration-transmethylation interdependence is controlled by a methyl group donor, S-adenosylmethionine (AdoMet) conversion to S-adenosylhomocysteine (AdoHcy), whose removal by subsequent hydrolysis to homocysteine counteract AdoHcy accumulation-induced OS and excitotoxicity. Methods: Rats received three consecutive intraperitoneal injections of thioacetamide (TAA) at 24 h intervals. We measured AdoMet and AdoHcy concentrations by HPLC-FD, glutathione (GSH/GSSG) ratio (Quantification kit). Results: AdoMet/AdoHcy ratio was reduced in the brain but not in the liver. The total glutathione level and GSH/GSSG ratio, decreased in TAA rats, were restored by AdoMet treatment. Conclusion: Data indicate that disturbance of redox homeostasis caused by AdoHcy in the TAA rat brain may represent a deleterious mechanism of brain damage in HE. The correction of the GSH/GSSG ratio following AdoMet administration indicates its therapeutic value in maintaining cellular redox potential in the cerebral cortex of ALF rats.

scholarly journals Evolution of Neuroaesthetic Variables in Portrait Paintings throughout the Renaissance

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 146 ◽  
Author(s):  
Ivan Correa-Herran ◽  
Hassan Aleem ◽  
Norberto Grzywacz
Keyword(s):  
Neural Function ◽  
Aesthetic Value ◽  
15Th Century ◽  
Sensory Evaluations ◽  
The Brain

To compose art, artists rely on a set of sensory evaluations performed fluently by the brain. The outcome of these evaluations, which we call neuroaesthetic variables, helps to compose art with high aesthetic value. In this study, we probed whether these variables varied across art periods despite relatively unvaried neural function. We measured several neuroaesthetic variables in portrait paintings from the Early and High Renaissance, and from Mannerism. The variables included symmetry, balance, and contrast (chiaroscuro), as well as intensity and spatial complexities measured by two forms of normalized entropy. The results showed that the degree of symmetry remained relatively constant during the Renaissance. However, the balance of portraits decayed abruptly at the end of the Early Renaissance, that is, at the closing of the 15th century. Intensity and spatial complexities, and thus entropies, of portraits also fell in such manner around the same time. Our data also showed that the decline of complexity and entropy could be attributed to the rise of chiaroscuro. With few exceptions, the values of aesthetic variables from the top of artists of the Renaissance resembled those of their peers. We conclude that neuroaesthetic variables have flexibility to change in brains of artists (and observers).

Biophysical basis of brain activity: implications for neuroimaging

2002 ◽  
Vol 35 (3) ◽  
pp. 287-325 ◽  
Author(s):  
Robert G. Shulman ◽  
Fahmeed Hyder ◽  
Douglas L. Rothman
Keyword(s):  
Energy Consumption ◽  
Magnetic Resonance ◽  
Neuronal Activity ◽  
Glucose Oxidation ◽  
Activity Level ◽  
Quantitative Relation ◽  
Cerebral Function ◽  
Level Of Activity ◽  
The Brain

1. Summary 2882. Introduction 2883. Relationship between neuroenergetics and neurotransmitter flux 2944. A model of coupling between neuroenergetics and neurotransmission 2965. Relationship between neuroenergetics and neural spiking frequency 2976. Comparison with previous electrophysiological and fMRI measurements 2987. Contributions of non-oxidative energetics to a primarily oxidative brain 2998. Possible explanation for non-oxidative energetics contributions 3009. A model of total neuronal activity to support cerebral function 30210. Implications for interpretation of fMRI studies 30511. The restless brain 30612. Acknowledgements 31013. Appendix A. CMRO2by13C-MRS 31014. Appendix B.Vcycand test of model 31315. Appendix C. CMRO2by calibrated BOLD 31616. Appendix D. Comparison of spiking activity of a neuronal ensemble with CMRO231817. References 320In vivo13C magnetic resonance spectroscopy (MRS) studies of the brain have quantitatively assessed rates of glutamate–glutamine cycle (Vcyc) and glucose oxidation (CMRGlc(ox)) by detecting 13C label turnover from glucose to glutamate and glutamine. Contrary to expectations from in vitro and ex vivo studies, the in vivo13C-MRS results demonstrate that glutamate recycling is a major metabolic pathway, inseparable from its actions of neurotransmission. Furthermore, both in the awake human and in the anesthetized rat brain, Vcyc and CMRGlc(ox) are stoichiometrically related, where more than two thirds of the energy from glucose oxidation supports events associated with glutamate neurotransmission. The high energy consumption of the brain measured at rest and its quantitative relation to neurotransmission reflects a sizeable activity level for the resting brain. The high activity of the non-stimulated brain, as measured by cerebral metabolic rate of oxygen use (CMRO2), establishes a new neurophysiological basis of cerebral function that leads to reinterpreting functional imaging data because the large baseline signal is commonly discarded in cognitive neuroscience paradigms. Changes in energy consumption (ΔCMRO2%) can also be obtained from magnetic resonance imaging (MRI) experiments, using the blood oxygen level- dependent (BOLD) image contrast, provided that all the separate parameters contributing to the functional MRI (fMRI) signal are measured. The BOLD-derived ΔCMRO2% when compared with alterations in neuronal spiking rate (Δν%) during sensory stimulation in the rat reveals a stoichiometric relationship, in good agreement with 13C-MRS results. Hence fMRI when calibrated so as to provide ΔCMRO2% can provide high spatial resolution evaluation of neuronal activity. Our studies of quantitative measurements of changes in neuroenergetics and neurotransmission reveal that a stimulus does not provoke an arbitrary amount of activity in a localized region, rather a total level of activity is required where the increment is inversely related to the level of activity in the non-stimulated condition. These biophysical experiments have established relationships between energy consumption and neuronal activity that provide novel insights into the nature of brain function and the interpretation of fMRI data.

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