scholarly journals Role of Neurotrophins in the Development and Function of Neural Circuits That Regulate Energy Homeostasis

2012 ◽  
Vol 48 (3) ◽  
pp. 654-659 ◽  
Author(s):  
Samira Fargali ◽  
Masato Sadahiro ◽  
Cheng Jiang ◽  
Amy L. Frick ◽  
Tricia Indall ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Neural Circuits ◽  
And Function

NG2-Glia, a New Player in Energy Balance

2018 ◽  
Vol 107 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Sarah C. Robins ◽  
Maia V. Kokoeva
Keyword(s):  
Radiation Therapy ◽  
Energy Balance ◽  
Progenitor Cells ◽  
Clinical Implication ◽  
Energy Homeostasis ◽  
Neural Circuits ◽  
Oligodendrocyte Progenitor Cells ◽  
Oligodendrocyte Progenitor ◽  
Physiological Outcomes

There is increasing evidence that glia act not only as neuronal support cells, but that they can also influence physiological outcomes via effects on neural signalling. The role of NG2-glia in this regard is especially enigmatic, as they are known to interact with neural circuits but their precise functions other than as oligodendrocyte progenitor cells remain elusive. Here, we summarise recent evidence suggesting that NG2-glia play a role in the maintenance of energy homeostasis, most notably via the support of leptin-sensing neural circuits. We also discuss the potential clinical implication of these findings specifically in the context of cranial radiation therapy.

scholarly journals An acetylation rheostat for the control of muscle energy homeostasis

2013 ◽  
Vol 51 (3) ◽  
pp. T101-T113 ◽  
Author(s):  
Keir Menzies ◽  
Johan Auwerx
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Biogenesis ◽  
Energy Homeostasis ◽  
Cellular Stress ◽  
Metabolic Stress ◽  
Effector Proteins ◽  
The Body ◽  
Recent Developments ◽  
And Function

In recent years, the role of acetylation has gained ground as an essential modulator of intermediary metabolism in skeletal muscle. Imbalance in energy homeostasis or chronic cellular stress, due to diet, aging, or disease, translate into alterations in the acetylation levels of key proteins which govern bioenergetics, cellular substrate use, and/or changes in mitochondrial content and function. For example, cellular stress induced by exercise or caloric restriction can alter the coordinated activity of acetyltransferases and deacetylases to increase mitochondrial biogenesis and function in order to adapt to low energetic levels. The natural duality of these enzymes, as metabolic sensors and effector proteins, has helped biologists to understand how the body can integrate seemingly distinct signaling pathways to control mitochondrial biogenesis, insulin sensitivity, glucose transport, reactive oxygen species handling, angiogenesis, and muscle satellite cell proliferation/differentiation. Our review will summarize the recent developments related to acetylation-dependent responses following metabolic stress in skeletal muscle.

scholarly journals Ion Channel Dysfunction and Neuroinflammation in Migraine and Depression

2021 ◽  
Vol 12 ◽  
Author(s):  
Emine Eren-Koçak ◽  
Turgay Dalkara
Keyword(s):  
Ion Channels ◽  
Ion Channel ◽  
Energy Homeostasis ◽  
Inflammatory Signaling ◽  
Pannexin 1 ◽  
Significant Heritability ◽  
Homeostatic Function ◽  
And Function ◽  
Excitability Of Neurons

Migraine and major depression are debilitating disorders with high lifetime prevalence rates. Interestingly these disorders are highly comorbid and show significant heritability, suggesting shared pathophysiological mechanisms. Non-homeostatic function of ion channels and neuroinflammation may be common mechanisms underlying both disorders: The excitation-inhibition balance of microcircuits and their modulation by monoaminergic systems, which depend on the expression and function of membrane located K+, Na+, and Ca+2 channels, have been reported to be disturbed in both depression and migraine. Ion channels and energy supply to synapses not only change excitability of neurons but can also mediate the induction and maintenance of inflammatory signaling implicated in the pathophysiology of both disorders. In this respect, Pannexin-1 and P2X7 large-pore ion channel receptors can induce inflammasome formation that triggers release of pro-inflammatory mediators from the cell. Here, the role of ion channels involved in the regulation of excitation-inhibition balance, synaptic energy homeostasis as well as inflammatory signaling in migraine and depression will be reviewed.

scholarly journals Comparative Genomic Characterization of Buffalo Fibronectin Type III Domain Proteins: Exploring the Novel Role of FNDC5/Irisin as a Ligand of Gonadal Receptors

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1207
Author(s):  
Siwen Wu ◽  
Faiz-ul Hassan ◽  
Yuhong Luo ◽  
Israr Fatima ◽  
Ishtiaq Ahmed ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Cellular Growth ◽  
Comparative Genomic ◽  
Fibronectin Type Iii ◽  
Genomic Characterization ◽  
Fibronectin Type Iii Domain ◽  
And Function ◽  
First Time ◽  
Estrogen Related Receptor

FN-III proteins are widely distributed in mammals and are usually involved in cellular growth, differentiation, and adhesion. The FNDC5/irisin regulates energy metabolism and is present in different tissues (liver, brain, etc.). The present study aimed to investigate the physiochemical characteristics and the evolution of FN-III proteins and FNDC5/irisin as a ligand targeting the gonadal receptors including androgen (AR), DDB1 and CUL4 associated factor 6 (DCAF6), estrogen-related receptor β (ERR-β), estrogen-related receptor γ (ERR-γ), Krüppel-like factor 15 (KLF15), and nuclear receptor subfamily 3 group C member 1 (NR3C1). Moreover, the putative role of irisin in folliculogenesis and spermatogenesis was also elucidated. We presented the molecular structure and function of 29 FN-III genes widely distributed in the buffalo genome. Phylogenetic analysis, motif, and conserved domain pattern demonstrated the evolutionary well-conserved nature of FN-III proteins with a variety of stable to unstable, hydrophobic to hydrophilic, and thermostable to thermo-unstable properties. The comparative structural configuration of FNDC5 revealed amino acid variations but still the FNDC5 structure of humans, buffalo, and cattle was quite similar to each other. For the first time, we predicted the binding scores and interface residues of FNDC5/irisin as a ligand for six representative receptors having a functional role in energy homeostasis, and a significant involvement in folliculogenesis and spermatogenesis in buffalo.

scholarly journals SAT-602 Hypothalamic P75 Neurotrophin Receptor Regulates Homeostatic Feeding and Food Anticipation

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Brandon Podyma ◽  
Dove Johnson ◽  
Laura Sipe ◽  
Katherine Battin ◽  
Parks Remcho ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Energy Homeostasis ◽  
Neural Circuits ◽  
Time Of Day ◽  
Energy Deficit ◽  
Neurotrophin Receptor ◽  
P75 Neurotrophin Receptor ◽  
Driving Time ◽  
Neurotrophin Signaling

Abstract Proper circadian alignment of feeding behavior is necessary to prevent metabolic disease, and thus it is imperative to identify the neural circuits and molecular players that coordinate energy homeostasis. Neurotrophin signaling has been implicated in both metabolic and circadian processes, thereby representing a good candidate for regulating neural circuits driving time-of-day dependent feeding and foraging behavior. Here, we demonstrate that mice lacking the p75 neurotrophin receptor, p75NTR, have a behavioral defect in their ability to adequately respond to energy deficit. In response to fasting, p75KO mice (1) decrease their refeeding food intake compared to controls. Furthermore, following several days of restricted feeding, they (2) are unable to develop food anticipatory behavior (FAA), a phenomenon believed to be the output of a food-entrained circadian oscillator that has yet to be anatomically defined. Strikingly, these two phenotypes are observed only during the daytime, and not at night. These defects lead to increased weight loss, but do not appear to be mediated by changes in peripheral hormones. Notably, these effects are also independent of a role of p75NTR in development, as a global, adult-inducible p75NTR knockout recapitulates the feeding behavior of germline knockout mice. Rather, we demonstrate that p75NTR is discretely expressed in two hypothalamic regions known to be important for feeding behavior, the arcuate (ARC) and dorsomedial (DMH) hypothalamus. We find that p75KO mice have reduced fasting-induced activation of ARC, but not DMH, neurons. In addition, we show that ARC AgRP neuron p75NTR is necessary for fasting-induced refeeding and daytime FAA. We further suggest that AgRP-p75NTR is necessary to mediate AgRP neuron phospho-CREB signaling in response to energy deficit. Finally, given previous reports of involvement of the DMH in food anticipation, we asked whether DMH-p75NTR is necessary for feeding behavior and food anticipation. Strikingly, we find that p75NTR in the DMH is also necessary for FAA, but not for the control of homeostatic feeding. These data establish p75NTR as a novel regulator of energy homeostasis that acts to gate behavioral responses to food scarcity. It further posits that p75NTR may functionally link two independent hypothalamic regions to a time-of-day dependence of circadian food anticipation.

scholarly journals Reverse Engineering and Robotics as Tools for Analyzing Neural Circuits

2021 ◽  
Vol 14 ◽  
Author(s):  
Ioannis Pisokas
Keyword(s):  
Reverse Engineering ◽  
Single Neuron ◽  
Neural Circuits ◽  
Central Complex ◽  
Insect Brain ◽  
Neuronal Circuits ◽  
And Function ◽  
Alternative Solutions ◽  
And Robotics

Understanding neuronal circuits that have evolved over millions of years to control adaptive behavior may provide us with alternative solutions to problems in robotics. Recently developed genetic tools allow us to study the connectivity and function of the insect nervous system at the single neuron level. However, neuronal circuits are complex, so the question remains, can we unravel the complex neuronal connectivity to understand the principles of the computations it embodies? Here, I illustrate the plausibility of incorporating reverse engineering to analyze part of the central complex, an insect brain structure essential for navigation behaviors such as maintaining a specific compass heading and path integration. I demonstrate that the combination of reverse engineering with simulations allows the study of both the structure and function of the underlying circuit, an approach that augments our understanding of both the computation performed by the neuronal circuit and the role of its components.

scholarly journals Astrocytes in Neural Circuits: Key Factors in Synaptic Regulation and Potential Targets for Neurodevelopmental Disorders

2021 ◽  
Vol 14 ◽  
Author(s):  
Xing Liu ◽  
Jun Ying ◽  
Xifeng Wang ◽  
Qingcui Zheng ◽  
Tiancheng Zhao ◽  
...  
Keyword(s):  
Neurodevelopmental Disorders ◽  
Neural Circuits ◽  
Key Factors ◽  
Space Filling ◽  
Synaptic Development ◽  
Synaptic Regulation ◽  
New Treatments ◽  
And Function ◽  
The Brain

Astrocytes are the major glial cells in the brain, which play a supporting role in the energy and nutritional supply of neurons. They were initially regarded as passive space-filling cells, but the latest progress in the study of the development and function of astrocytes highlights their active roles in regulating synaptic transmission, formation, and plasticity. In the concept of “tripartite synapse,” the bidirectional influence between astrocytes and neurons, in addition to their steady-state and supporting function, suggests that any negative changes in the structure or function of astrocytes will affect the activity of neurons, leading to neurodevelopmental disorders. The role of astrocytes in the pathophysiology of various neurological and psychiatric disorders caused by synaptic defects is increasingly appreciated. Understanding the roles of astrocytes in regulating synaptic development and the plasticity of neural circuits could help provide new treatments for these diseases.

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

Role of the Cilia Membrane in Control of Microtubule Sliding

1980 ◽  
Vol 38 ◽  
pp. 612-615
Author(s):  
Edna S. Kaneshiro
Keyword(s):  
Control Mechanism ◽  
Beat Frequency ◽  
Surface Membrane ◽  
Ciliary Membrane ◽  
Ciliary Beating ◽  
Ciliary Reversal ◽  
Voltage Dependent ◽  
Reversal Mechanism ◽  
And Function

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.

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