Glutamic Acid and Glucose As Substrates for Mammalian Brain

1951 ◽  
Vol 97 (409) ◽  
pp. 674-680 ◽  
Author(s):  
H. McIlwain
Keyword(s):  
Glutamic Acid ◽  
Functional Activity ◽  
Metabolic Effects ◽  
Mammalian Brain ◽  
The Past ◽  
The Brain

Effects of substances on the respiration of unstimulated portions of mammalian brain have been used in the past as aids to understanding or suggesting their actions on the brain in vivo. The present paper gives data with respect to glucose and glutamic acid, which show some of the limitations of such interpretations. It also describes the application of new experimental means of examining the metabolic effects of added substances in relation to the functional activity of the brain.

scholarly journals Recapitulate development to promote axonal regeneration: good or bad approach?

2006 ◽  
Vol 361 (1473) ◽  
pp. 1565-1574 ◽  
Author(s):  
Marie T Filbin
Keyword(s):  
Spinal Cord ◽  
Axonal Regeneration ◽  
Molecular Level ◽  
Signal Transduction Pathway ◽  
Developmental Changes ◽  
Transduction Pathway ◽  
The Past ◽  
Brain And Spinal Cord ◽  
The Brain

In the past decade there has been an explosion in our understanding, at the molecular level, of why axons in the adult, mammalian central nervous system (CNS) do not spontaneously regenerate while their younger counterparts do. Now a number of inhibitors of axonal regeneration have been described, some of the receptors they interact with to transduce the inhibitory signal are known, as are some of the steps in the signal transduction pathway that is responsible for inhibition. In addition, developmental changes in the environment and in the neurons themselves are also now better understood. This knowledge in turn reveals novel, putative sites for drug development and therapeutic intervention after injury to the brain and spinal cord. The challenge now is to determine which of these putative treatments are the most effective and if they would be better applied in combination rather than alone. In this review I will summarize what we have learnt about these molecules and how they signal. Importantly, I will also describe approches that have been shown to block inhibitors and encourage regeneration in vivo . I will also speculate on what the differences are between the neonatal and adult CNS that allow the former to regenerate and the latter not to.

scholarly journals An argument for broad use of high efficacy treatments in early multiple sclerosis

2019 ◽  
Vol 7 (1) ◽  
pp. e636 ◽  
Author(s):  
James M. Stankiewicz ◽  
Howard L. Weiner
Keyword(s):  
Multiple Sclerosis ◽  
Treatment Approach ◽  
Disease Course ◽  
Long Term Outcomes ◽  
The Past ◽  
Recent Developments ◽  
The Brain

Two different treatment paradigms are most often used in multiple sclerosis (MS). An escalation or induction approach is considered when treating a patient early in the disease course. An escalator prioritizes safety, whereas an inducer would favor efficacy. Our understanding of MS pathophysiology has evolved with novel in vivo and in vitro observations. The treatment landscape has also shifted significantly with the approval of over 10 new medications over the past decade alone. Here, we re-examine the treatment approach in light of these recent developments. We believe that recent work suggests that early prediction of the disease course is fraught, the amount of damage to the brain that MS causes is underappreciated, and its impact on patient function oftentimes is underestimated. These concerns, coupled with the recent availability of agents that allow a better therapeutic effect without compromising safety, lead us to believe that initiating higher efficacy treatments early is the best way to achieve the best possible long-term outcomes for people with MS.

scholarly journals A Gustotopic Map of Taste Qualities in the Mammalian Brain

Science ◽  
2011 ◽  
Vol 333 (6047) ◽  
pp. 1262-1266 ◽  
Author(s):  
Xiaoke Chen ◽  
Mariano Gabitto ◽  
Yueqing Peng ◽  
Nicholas J. P. Ryba ◽  
Charles S. Zuker
Keyword(s):  
Taste Receptor ◽  
Taste Quality ◽  
Mammalian Brain ◽  
Taste System ◽  
Two Photon ◽  
Central Representation ◽  
The Brain ◽  
Cortical Field ◽  
Taste Coding

The taste system is one of our fundamental senses, responsible for detecting and responding to sweet, bitter, umami, salty, and sour stimuli. In the tongue, the five basic tastes are mediated by separate classes of taste receptor cells each finely tuned to a single taste quality. We explored the logic of taste coding in the brain by examining how sweet, bitter, umami, and salty qualities are represented in the primary taste cortex of mice. We used in vivo two-photon calcium imaging to demonstrate topographic segregation in the functional architecture of the gustatory cortex. Each taste quality is represented in its own separate cortical field, revealing the existence of a gustotopic map in the brain. These results expose the basic logic for the central representation of taste.

scholarly journals A Guide to Emerging Technologies for Large-Scale and Whole-Brain Optical Imaging of Neuronal Activity

2018 ◽  
Vol 41 (1) ◽  
pp. 431-452 ◽  
Author(s):  
Siegfried Weisenburger ◽  
Alipasha Vaziri
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Mammalian Brain ◽  
Large Area ◽  
The Past ◽  
Hybrid Approaches ◽  
Large Populations ◽  
Temporal And Spatial ◽  
The Brain ◽  
Neuroscience Community

The mammalian brain is a densely interconnected network that consists of millions to billions of neurons. Decoding how information is represented and processed by this neural circuitry requires the ability to capture and manipulate the dynamics of large populations at high speed and high resolution over a large area of the brain. Although the use of optical approaches by the neuroscience community has rapidly increased over the past two decades, most microscopy approaches are unable to record the activity of all neurons comprising a functional network across the mammalian brain at relevant temporal and spatial resolutions. In this review, we survey the recent development in optical technologies for Ca2+imaging in this regard and provide an overview of the strengths and limitations of each modality and its potential for scalability. We provide guidance from the perspective of a biological user driven by the typical biological applications and sample conditions. We also discuss the potential for future advances and synergies that could be obtained through hybrid approaches or other modalities.

scholarly journals Lessons from Tau-Deficient Mice

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yazi D. Ke ◽  
Alexandra K. Suchowerska ◽  
Julia van der Hoven ◽  
Dineeka M. De Silva ◽  
Christopher W. Wu ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Mouse Strains ◽  
Motor Deficits ◽  
Transgenic Mouse Models ◽  
The Past ◽  
Number Of Publications ◽  
The Brain ◽  
Deficient Mice

Both Alzheimer's disease (AD) and frontotemporal dementia (FTD) are characterized by the deposition of hyperphosphorylated forms of the microtubule-associated protein tau in neurons and/or glia. This unifying pathology led to the umbrella term “tauopathies” for these conditions, also emphasizing the central role of tau in AD and FTD. Generation of transgenic mouse models expressing human tau in the brain has contributed to the understanding of the pathomechanistic role of tau in disease. To reveal the physiological functions of tauin vivo, several knockout mouse strains with deletion of the tau-encodingMAPTgene have been established over the past decade, using different gene targeting constructs. Surprisingly, when initially introduced tau knockout mice presented with no overt phenotype or malformations. The number of publications using tau knockout mice has recently markedly increased, and both behavioural changes and motor deficits have been identified in aged mice of certain strains. Moreover, tau knockout mice have been instrumental in identifying novel functions of tau, both in cultured neurons andin vivo. Importantly, tau knockout mice have significantly contributed to the understanding of the pathophysiological interplay between Aβand tau in AD. Here, we review the literature that involves tau knockout mice to summarize what we have learned so far from depleting tauin vivo.

scholarly journals Synchronization of mammalian motile cilia in the brain with hydrodynamic forces

2019 ◽  
Author(s):  
Nicola Pellicciotta ◽  
Evelyn Hamilton ◽  
Jurij Kotar ◽  
Marion Faucourt ◽  
Nathalie Degehyr ◽  
...  
Keyword(s):  
Mechanistic Model ◽  
Hydrodynamic Forces ◽  
Coordination Mechanism ◽  
Mammalian Brain ◽  
Similar Frequency ◽  
Multiciliated Cells ◽  
Motile Cilia ◽  
External Flows ◽  
The Brain

Motile cilia are widespread across the animal and plant kingdoms, displaying complex collective dynamics central to their physiology. Their coordination mechanism is not generally understood, with pre-vious work mainly focusing on algae and protists. We study here the synchronization of cilia beat in multiciliated cells from brain ven-tricles. The response to controlled oscillatory external flows shows that strong flows at a similar frequency to the actively beating cilia can entrain cilia oscillations. We find that the hydrodynamic forces required for this entrainment strongly depend on the number of cilia per cell. Cells with few cilia (up to five) can be entrained at flows comparable to the cilia-driven flows reported in vivo. Simulations of a minimal model of cilia interacting hydrodynamically show the same trends observed in cilia. Our results suggest that hydrody-namic forces between cilia are sufficient to be the mechanism behind the synchronization of mammalian brain cilia dynamics.Significance StatementIt is shown experimentally, and also reproducing key qualitative results in a minimal mechanistic model simulated numerically, that in the motile cilia of the brain hydrodynamic forces of the magnitude that cilia themselves can generate are sufficient to establish the coordination of dynamics which is so crucial phys-iologically. This is the first experiment of its kind on multicilated cells, the key result is the unexpected importance of cilia num-ber per cell, with cells with fewer cilia much more susceptible to external flows. This finding changes the way in which we think about the question of collective cilia beating - it is not correct to simply examine isolated cilia and draw conclusions about the behaviour of cilia assemblies in multiciliated cells.

Fever: A Hot Topic

Physiology ◽  
1986 ◽  
Vol 1 (1) ◽  
pp. 25-27
Author(s):  
MJ Kluger
Keyword(s):  
Body Temperature ◽  
Interleukin 1 ◽  
White Blood Cells ◽  
Point Contact ◽  
In Vivo Studies ◽  
Set Point ◽  
The Past ◽  
The Brain

Fever is the regulation of body temperature at an elevated "set point." Contact with a variety of pathogens, such as viruses or bacteria, will result in the release of a small protein, endogenous pyrogen or interleukin 1, from the host's white blood cells. This protein circulates to the brain where it is thought to raise the temperature set point via the production of a prostaglandin. Fevers occur throughout the vertebrates. The cold-blooded vertebrates (fishes, amphibians, reptiles) raise their body temperature by behaviorally selecting a warmer microhabitat. Warm-blooded vertebrates (birds and mammals) use both physiological and behavioral means to raise core temperature. Over the past decade data from both in vitro and in vivo studies support the hypothesis that moderate fevers are beneficial to the host;that is, fever as evolved as an adaptation to reduce the severity of infection.

A Note on the Ammonia and Glutamine Content of the Cerebrospinal Fluid

1949 ◽  
Vol 95 (398) ◽  
pp. 148-152 ◽  
Author(s):  
D. Richter ◽  
R.M.C. Dawson ◽  
Linford Rees
Keyword(s):  
Cerebrospinal Fluid ◽  
Glutamic Acid ◽  
Ammonium Chloride ◽  
Inhibitory Action ◽  
Enzyme System ◽  
Toxic Action ◽  
Irritant Action ◽  
The Brain

Tashiro (1922) showed that the isolated frog nerve liberates ammonia on stimulation, and Richter and Dawson (1948) have recently found that ammonia is liberated on stimulation by the brain. Ammonia is very toxic to the brain, on which it has an irritant action; but the brain may be protected to some extent by the enzyme system described by Krebs (1935), which can detoxicate ammonia by combination with glutamic acid to form glutamine. Sapirstein (1943) obtained evidence that this system is active in vivo by showing that glutamic acid increases the resistance of animals to convulsions produced by injecting ammonium chloride. The toxic action of ammonia on the brain is also of interest in connection with the view that it may be concerned in certain forms of epilepsy (Harris, 1945). This view is supported by the observations of Price, Waelsch and Putnam (1943) on the inhibitory action of glutamic acid on petit mal attacks.

The Complex Relationships between Sex and the Brain

2019 ◽  
Vol 26 (2) ◽  
pp. 156-169 ◽  
Author(s):  
Daphna Joel ◽  
Alicia Garcia-Falgueras ◽  
Dick Swaab
Keyword(s):  
Sexual Differentiation ◽  
Mammalian Brain ◽  
The Past ◽  
Animal Data ◽  
Health And Disease ◽  
Complex Relationships ◽  
The Individual ◽  
Complex Scenario ◽  
Internal And External Factors ◽  
The Brain

In the past decennia, our understanding of the sexual differentiation of the mammalian brain has dramatically changed. The simple model according to which testosterone masculinizes the brain of males away from a default female form, was replaced with a complex scenario, according to which sex effects on the brain of both females and males are exerted by genetic, hormonal, and environmental factors. These factors act via multiple partly independent mechanisms that may vary according to internal and external factors. These observations led to the “mosaic” hypothesis—the expectation of high variability in the degree of “maleness”/“femaleness” of different features within a single brain. Here, we briefly review animal data that form the basis of current understanding of sexual differentiation; present, in this context, the results of co-analyses of human brain measures obtained by magnetic resonance imaging or postmortem; discuss criticisms and controversies of the mosaic hypothesis and implications for research; and conclude that co-analysis of several (preferably, many) features and going back from the group level to that of the individual would advance our understanding of the relations between sex and the brain in health and disease.

scholarly journals Lactate-mediated glia-neuronal signalling in the mammalian brain

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
F. Tang ◽  
S. Lane ◽  
A. Korsak ◽  
J. F. R. Paton ◽  
A. V. Gourine ◽  
...  
Keyword(s):  
Mammalian Brain ◽  
Frontal Brain ◽  
Potential Source ◽  
Neuronal Signalling ◽  
Signalling Molecule ◽  
Principal Source ◽  
Lactate Uptake ◽  
The Brain ◽  
Excitatory Transmitter

Abstract Astrocytes produce and release L-lactate as a potential source of energy for neurons. Here we present evidence that L-lactate, independently of its caloric value, serves as an astrocytic signalling molecule in the locus coeruleus (LC). The LC is the principal source of norepinephrine to the frontal brain and thus one of the most influential modulatory centers of the brain. Optogenetically activated astrocytes release L-lactate, which excites LC neurons and triggers release of norepinephrine. Exogenous L-lactate within the physiologically relevant concentration range mimics these effects. L-lactate effects are concentration-dependent, stereo-selective, independent of L-lactate uptake into neurons and involve a cAMP-mediated step. In vivo injections of L-lactate in the LC evokes arousal similar to the excitatory transmitter, L-glutamate. Our results imply the existence of an unknown receptor for this ‘glio-transmitter’.

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