Energy metabolism in glutamatergic neurons, GABAergic neurons and astrocytes in primary cultures

Neural plasticity is associated with memory formation. The coordinated refinement and interaction between cortical glutamatergic and GABAergic neurons remain elusive in associative memory, which we examine in a mouse model of associative learning. In the mice that show odorant-induced whisker motion after pairing whisker and odor stimulations, the barrel cortical glutamatergic and GABAergic neurons are recruited to encode the newly learnt odor signal alongside the innate whisker signal. These glutamatergic neurons are functionally upregulated, and GABAergic neurons are refined in a homeostatic manner. The mutual innervations between these glutamatergic and GABAergic neurons are upregulated. The analyses by high throughput sequencing show that certain microRNAs related to regulating synapses and neurons are involved in this cross-modal reflex. Thus, the coactivation of the sensory cortices through epigenetic processes recruits their glutamatergic and GABAergic neurons to be the associative memory cells as well as drive their coordinated refinements toward the optimal state for the storage of the associated signals.

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Cell type-specific modulation of sensory and affective components of itch in the periaqueductal gray

Nature Communications ◽

10.1038/s41467-019-12316-0 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 4

Author(s):

Vijay K. Samineni ◽

Jose G. Grajales-Reyes ◽

Saranya S. Sundaram ◽

Judy J. Yoo ◽

Robert W. Gereau

Keyword(s):

Neural Circuits ◽

Periaqueductal Gray ◽

Gabaergic Neurons ◽

Cell Type ◽

Glutamatergic Neurons ◽

Neuronal Populations ◽

Chronic Itch ◽

Cell Type Specific ◽

Bidirectional Modulation ◽

Affective Components

Abstract Itch is a distinct aversive sensation that elicits a strong urge to scratch. Despite recent advances in our understanding of the peripheral basis of itch, we know very little regarding how central neural circuits modulate acute and chronic itch processing. Here we establish the causal contributions of defined periaqueductal gray (PAG) neuronal populations in itch modulation in mice. Chemogenetic manipulations demonstrate bidirectional modulation of scratching by neurons in the PAG. Fiber photometry studies show that activity of GABAergic and glutamatergic neurons in the PAG is modulated in an opposing manner during chloroquine-evoked scratching. Furthermore, activation of PAG GABAergic neurons or inhibition of glutamatergic neurons resulted in attenuation of scratching in both acute and chronic pruritis. Surprisingly, PAG GABAergic neurons, but not glutamatergic neurons, may encode the aversive component of itch. Thus, the PAG represents a neuromodulatory hub that regulates both the sensory and affective aspects of acute and chronic itch.

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A2B receptor activation promotes glycogen synthesis in astrocytes through modulation of gene expression

AJP Cell Physiology ◽

10.1152/ajpcell.00202.2002 ◽

2003 ◽

Vol 284 (3) ◽

pp. C696-C704 ◽

Cited By ~ 44

Author(s):

Igor Allaman ◽

Sylvain Lengacher ◽

Pierre J. Magistretti ◽

Luc Pellerin

Keyword(s):

Energy Metabolism ◽

Supply And Demand ◽

Glycogen Synthesis ◽

Primary Cultures ◽

Receptor Activation ◽

Brain Energy Metabolism ◽

Receptor Subtype ◽

Dependent Manner ◽

Brain Energy

Adenosine has been proposed as a key factor regulating the metabolic balance between energy supply and demand in the central nervous system. Because astrocytes represent an important cellular element in the control of brain energy metabolism, we investigated whether adenosine could induce long-term changes of glycogen levels in primary cultures of mouse cortical astrocytes. We observed that adenosine increased glycogen content, up to 300%, in a time- (maximum at 8 h) and concentration-dependent manner with an EC50 of 9.69 μM. Pharmacological experiments using the broad-spectrum agonist 5′-( N-ethylcarboxamido)adenosine (NECA) and specific agonists for the A1, A2A, and A3receptors [ N 6-cyclopentyladenosine (CPA), CGS-21680, and IB-MECA, respectively] suggest that the effect of adenosine is mediated through activation of the low-affinity A2B adenosine receptor subtype. Interestingly, adenosine induces in parallel the expression of the protein targeting to glycogen (PTG), one of the protein phosphatase-1 glycogen-targeting subunits that has been implicated in the control of glycogen levels in various tissues. These results indicate that adenosine can exert long-term control over glycogen levels in astrocytes and might therefore play a significant role in physiological and/or pathological processes involving long-term modulation of brain energy metabolism.

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Evidence that levels of malate dehydrogenase and fumarase are increased by cAMP in rat myotubes

AJP Cell Physiology ◽

10.1152/ajpcell.1984.247.1.c33 ◽

1984 ◽

Vol 247 (1) ◽

pp. C33-C38 ◽

Cited By ~ 9

Author(s):

J. C. Lawrence ◽

W. J. Salsgiver

Keyword(s):

Energy Metabolism ◽

Malate Dehydrogenase ◽

Potential Role ◽

Primary Cultures ◽

Phosphodiesterase Inhibitors ◽

Dibutyryl Camp ◽

Rat Skeletal Muscle ◽

Oxidative Energy Metabolism ◽

Enzymes Of Energy Metabolism

We have investigated the potential role of adenosine 3',5'-cyclic monophosphate (cAMP) in controlling levels of enzymes of energy metabolism in primary cultures of rat skeletal muscle cells. Incubating myotubes with cholera toxin or forskolin (2 persistent activators of adenylate cyclase) significantly increased the levels of two enzymes of oxidative metabolism, fumarase and malate dehydrogenase. These enzymes were also increased (1.5- to 2.0-fold) by phosphodiesterase inhibitors (caffeine, theophylline, theobromine, 3-isobutyl-1-methylxanthine, papaverine, MJ 1988, Ro 20–1724, or SQ 20009) and the cAMP derivatives: 8-bromo-cAMP or dibutyryl cAMP. In contrast two enzymes of glycolytic metabolism, lactate dehydrogenase and pyruvate kinase, were not consistently affected by these agents. The results presented provide strong evidence that an increase in cAMP can lead to an increase in certain enzymes of oxidative energy metabolism.

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Cadherin-13 is a critical regulator of GABAergic modulation in human stem-cell-derived neuronal networks

Molecular Psychiatry ◽

10.1038/s41380-021-01117-x ◽

2021 ◽

Author(s):

Britt Mossink ◽

Jon-Ruben van Rhijn ◽

Shan Wang ◽

Katrin Linda ◽

Maria R. Vitale ◽

...

Keyword(s):

Gabaergic Neurons ◽

Inhibitory Synapses ◽

Disease Genes ◽

Electrode Arrays ◽

Glutamatergic Neurons ◽

Human Neurons ◽

Induced Pluripotent ◽

Micro Electrode Arrays ◽

Gabaergic Modulation

AbstractActivity in the healthy brain relies on a concerted interplay of excitation (E) and inhibition (I) via balanced synaptic communication between glutamatergic and GABAergic neurons. A growing number of studies imply that disruption of this E/I balance is a commonality in many brain disorders; however, obtaining mechanistic insight into these disruptions, with translational value for the patient, has typically been hampered by methodological limitations. Cadherin-13 (CDH13) has been associated with autism and attention-deficit/hyperactivity disorder. CDH13 localizes at inhibitory presynapses, specifically of parvalbumin (PV) and somatostatin (SST) expressing GABAergic neurons. However, the mechanism by which CDH13 regulates the function of inhibitory synapses in human neurons remains unknown. Starting from human-induced pluripotent stem cells, we established a robust method to generate a homogenous population of SST and MEF2C (PV-precursor marker protein) expressing GABAergic neurons (iGABA) in vitro, and co-cultured these with glutamatergic neurons at defined E/I ratios on micro-electrode arrays. We identified functional network parameters that are most reliably affected by GABAergic modulation as such, and through alterations of E/I balance by reduced expression of CDH13 in iGABAs. We found that CDH13 deficiency in iGABAs decreased E/I balance by means of increased inhibition. Moreover, CDH13 interacts with Integrin-β1 and Integrin-β3, which play opposite roles in the regulation of inhibitory synaptic strength via this interaction. Taken together, this model allows for standardized investigation of the E/I balance in a human neuronal background and can be deployed to dissect the cell-type-specific contribution of disease genes to the E/I balance.

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Expression of serotonin 1A and 2A receptors in molecular- and projection-defined neurons of the mouse insular cortex

10.21203/rs.2.20095/v2 ◽

2020 ◽

Author(s):

Anes Ju ◽

Beatriz Fernandez-Arroyo ◽

Yifan Wu ◽

Débora Jacky ◽

Anna Beyeler

Keyword(s):

Partial Agonist ◽

Insular Cortex ◽

Initial Step ◽

Gabaergic Neurons ◽

Binding Potential ◽

Projection Neurons ◽

Glutamatergic Neurons ◽

Neuronal Populations ◽

Serotonin 2A

Abstract The serotonin (5-HT) system is the target of multiple anxiolytics, including Buspirone, which is a partial agonist of the serotonin 1A receptor (5‑HT1A). Similarly, ligands of the serotonin 2A receptor (5-HT2A) were shown to alter anxiety level. The 5-HT1A and 2A receptors are widely expressed across the brain, but the target region(s) underlying the influence of those receptors on anxiety remain unknown. Interestingly, recent studies in human and non-human primates have shown that the 5-HT1A and 5-HT2A binding potential within the insular cortex (insula) are correlated to anxiety. As an initial step to define the function of 5‑HT transmission in the insula, we quantified the proportion of specific neuronal populations of the insula expressing 5‑HT1A or 5‑HT2A. We analyzed seven neural populations, including three defined by a molecular marker (putative glutamate, GABA or parvalbumin), and four defined by their projections to different downstream targets. First, we found that more than 70% of putative glutamatergic neurons, and only 30% of GABAergic neurons express the 5‑HT1A. Second, within insular projection neurons, 5-HT1A is highly expressed (75-80%) in the populations targeting one sub-nuclei of the amygdala (central or basolateral), or targeting the rostral or caudal sections of the lateral hypothalamus (LH). Similarly, 70% of putative glutamatergic neurons and only 30% of insular GABAergic neurons contain 5-HT2A. Finally, the 5-HT2A is present in a majority of insula-amygdala and insula-LH projection neurons (73-82%). These observations suggest that most glutamatergic neurons can respond to 5‑HT through 5-HT1A or 5‑HT2A in the insula, and that 5-HT directly affects a limited number of GABAergic neurons. This study defines a molecular and neuroanatomical map of the 5-HT system within the insular cortex, providing ground knowledge to identify the potential role of serotonergic modulation of selective insular populations in anxiety.

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ID2011 Potential strategies to improve Temozolomide/ radiation therapy of malignant gliomas by targeting glycolytic energy metabolism

Biomedical Research and Therapy ◽

10.15419/bmrat.v4is.255 ◽

2017 ◽

Vol 4 (S) ◽

pp. 45

Author(s):

Kalyani Thakur

Keyword(s):

Cell Proliferation ◽

Radiation Therapy ◽

Energy Metabolism ◽

Cell Line ◽

Primary Cultures ◽

Malignant Gliomas ◽

Cellular Damage ◽

Established Cell Line ◽

Current Standard ◽

Combination Treatments

The current standard treatment of Malignant Gliomas includes surgery, followed by Temozolomide (TMZ) - Radiotherapy. It leads to increased survival as compared to radiotherapy alone. However, haematological toxicities are also increased by the combination treatments. Therefore, it is important to carry out further preclinical studies, to develop more effective treatment for these tumors. 2-Deoxy-D-Glucose (2-DG), an inhibitor of glycolytic energy metabolism, has been shown earlier to differentially inhibit repair processes, growth and survival of cancer cells. It has been tolerated very well in combination with radiotherapy in clinical trials on Malignant Gliomas. In this study, we investigated the effects of combination of clinically relevant concentrations of 2-DG (0.5mM and 1mM) and TMZ (2µM and 5µM) ± Radiation (1Gy) on cell proliferation, total cellular damage (TCD) and colony formation in an established Glioblastoma cell line (U251MG), and primary cultures derived from malignant glioma tumor pieces. The monolayer cultures were grown on cover slips and stained with Acridine Orange (0.002%) after drug treatments and irradiation, for the study of cellular damage and death. Exponentially growing cells were exposed to drugs and Gamma irradiation. Drugs were removed 4 hrs after irradiation and cultures were processed for different assays of cell death and damage. Our results showed that combination of 2-DG with TMZ±Radiation significantly inhibited the cell proliferation up to 6 days. The TCD was significantly increased by the combination of drugs in primary as well as in established cell line. Cell proliferation as measured by MTT assay showed that drugs ± radiation significantly reduced proliferation response. Cell survival inhibition after combination of TMZ+2-DG+Gamma (2µM+0.5mM+1Gy) showed more than additive effects. These results suggest that targeting glycolytic energy metabolism by agents such as 2-DG can enhance the efficacy of TMZ+Radiation Therapy for Malignant Gliomas, without increasing toxic side effects

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