scholarly journals Abundance of the α-subunits of Gi1, Gi2 and Go in synaptosomal membranes from several regions of the rat brain is increased in hypothyroidism

1991 ◽  
Vol 275 (1) ◽  
pp. 183-186 ◽  
Author(s):  
M Orford ◽  
D Mazurkiewicz ◽  
G Milligan ◽  
D Saggerson
Keyword(s):  
G Protein ◽  
Signalling Pathways ◽  
Synaptosomal Membranes ◽  
Protein Subunits ◽  
Functional Changes ◽  
Alpha Subunits ◽  
The Central Nervous System ◽  
Quantitative Immunoblotting ◽  
The Brain ◽  
Α Subunits

1. Rats (4 weeks old) were made hypothyroid by treatment with propylthiouracil together with a low-iodine diet for a further period of 4 weeks. Synaptosomal membranes were obtained from six anatomical regions of the brain. 2. The abundances in these membranes of the G-protein alpha-subunits Gi1 alpha, Gi2 alpha and Go alpha were measured by quantitative immunoblotting. 3. Hypothyroidism significantly increased the abundances of all three G-protein subunits in membranes from the cerebral cortex and the striatum. In the medulla oblongata and the hippocampus the abundances of Gi2 alpha and Go alpha were increased significantly. By contrast, in the cerebellum only Go alpha was increased, and in the hypothalamus only Gi2 alpha was increased. 4. It is suggested that this up-regulation of G-protein abundances may modify signalling pathways and may contribute to the functional changes that are observed in the central nervous system in hypothyroidism.

Characterization of heterotrimeric G-proteins in adult Acanthocheilonema viteae

1996 ◽  
Vol 320 (2) ◽  
pp. 459-466 ◽  
Author(s):  
GRANT Karen R. ◽  
Margaret M. HARNETT ◽  
Graeme MILLIGAN ◽  
William HARNETT
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Eukaryotic Cells ◽  
Heterotrimeric G Proteins ◽  
Protein Subunits ◽  
Acanthocheilonema Viteae ◽  
Affinity Labelling ◽  
Α Subunits

Heterotrimeric G-proteins have been found in eukaryotic cells, from yeast to humans, but have received little attention, to date, with respect to parasitic organisms. We now present the first report of the characterization of heterotrimeric G-proteins expressed in a filarial nematode, Acanthocheilonema viteae. Using a combination of (i) affinity labelling with [α-32P]GTP; (ii) ADP-ribosylation with cholera toxin and pertussis toxin; (iii) Western blotting with a panel of anti-G-protein antibodies; and (iv) reverse transcriptase-PCR with degenerate G-protein oligonucleotide primers followed by hybridization analysis using oligonucleotides specific for individual G-protein subunits, we demonstrate that adult A. viteae expresses homologues of the β1-and/or β2-like subunits and α-subunits of the Gs, Gi, Gq and G12 subfamilies found in mammals. The role which these G-proteins may play in the biology of the organism is discussed.

scholarly journals Effect of 5-hydroxytryptamine Receptor in the Lower Esophageal Sphincter Regulation Mechanism

2020 ◽  
Vol 3 (6) ◽  
Author(s):  
Hefei Li ◽  
Junfeng Liu ◽  
Xixuan Zhang ◽  
Zhiwei Lai ◽  
Zhen Gao ◽  
...  
Keyword(s):  
G Protein ◽  
G Protein Coupled Receptors ◽  
Regulation Mechanism ◽  
Visceral Sensitivity ◽  
Gastrointestinal Dysfunction ◽  
Secretion Regulation ◽  
The Central Nervous System ◽  
Esophageal Sphincter ◽  
G Protein Coupled ◽  
The Brain

As a neurotransmitter and avascular active substance, the 5-hydroxytryptamine (5-HT, serotonin) is widely distributed in the central nervous system and surrounding tissues. The 5-HT can play its role by acting on its corresponding 5-HT receptor. Nowadays, the 5-HT receptor can be classified into seven, according to different signal transduction method of receptors, the 5-HT3 receptor belongs to the ligand-gated ion channels, while other six 5-HT receptors are involved into the G protein-coupled receptors and play the biological role by binding to specific G protein-coupled receptors (GPCRs) on the surface of the cell membrane. The 5-HT plays an important role in the brain-gut information transmission and studies showed that the physiological stimulations like having meals, and pathological stimulations like ischemia and stress could promote the release of the 5-HT. In the gastrointestinal tract, the 5-HT is closely related to gastrointestinal sensitivity, gastrointestinal movement and secretion regulation, as well as many gastrointestinal dysfunction disorders, such as gastrointestinal power and visceral sensitivity abnormality and abnormalities of brain-gut axis.

Alcohol Pathophysiology

2010 ◽  
Vol 24 (4) ◽  
pp. 215-230 ◽  
Author(s):  
Claude Tomberg
Keyword(s):  
Neuronal Networks ◽  
Molecular Data ◽  
Functional Changes ◽  
Wide Range ◽  
Cognitive Disturbances ◽  
Specific Proteins ◽  
The Central Nervous System ◽  
Functional Circuitry ◽  
The Brain

There is no specialized alcohol addiction area in the brain; rather, alcohol acts on a wide range of excitatory and inhibitory nervous networks to modulate neurotransmitters actions by binding with and altering the function of specific proteins. With no hemato-encephalic barrier for alcohol, its actions are strongly related to the amount of intake. Heavy alcohol intake is associated with both structural and functional changes in the central nervous system with long-term neuronal adaptive changes contributing to the phenomena of tolerance and withdrawal. The effects of alcohol on the function of neuronal networks are heterogeneous. Because ethanol affects neural activity in some brain sites but is without effect in others, its actions are analyzed in terms of integrated connectivities in the functional circuitry of neuronal networks, which are of particular interest because of the cognitive interactions discussed in the manuscripts contributing to this review. Recent molecular data are reviewed as a support for the other contributions dealing with cognitive disturbances related to alcohol acute and addicted consumption.

scholarly journals OCTA in neurodegenerative optic neuropathies: emerging biomarkers at the eye–brain interface

2020 ◽  
Vol 12 ◽  
pp. 251584142095050
Author(s):  
Samuel Asanad ◽  
Isa Mohammed ◽  
Alfredo A. Sadun ◽  
Osamah J. Saeedi
Keyword(s):  
Optical Coherence Tomography Angiography ◽  
Vascular Anatomy ◽  
Clinical Marker ◽  
Functional Changes ◽  
Quantitative Measurements ◽  
Brain Interface ◽  
The Central Nervous System ◽  
Current Article ◽  
Vascular Biomarkers ◽  
The Brain

Optical coherence tomography angiography (OCTA) is an emerging technique for non-invasively imaging the ocular vasculature, enabling quantitative measurements of retinal vascular anatomy. As extensions of the central nervous system, the optic nerve and the retina share many vascular characteristics with the brain. Measuring the structural and functional changes within the ocular vasculature may be useful as an objective approach for non-invasively evaluating the cerebrovascular architecture. The current article reviews the most recent applications of OCTA imaging at the eye-brain interface and highlights the emerging vascular biomarkers for neurodegenerative optic neuropathies, as reported in Alzheimer’s disease, Parkinson’s disease, schizophrenia, and mitochondrial optic neuropathies. These ophthalmologic findings offer objective measures of a more accessible clinical marker and may improve our understanding of neurodegenerative disease.

scholarly journals Signalling functions and biochemical properties of pertussis toxin-resistant G-proteins

1997 ◽  
Vol 321 (3) ◽  
pp. 561-571 ◽  
Author(s):  
Timothy A. FIELDS ◽  
Patrick J. CASEY
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Biochemical Properties ◽  
Signalling Pathways ◽  
Heterotrimeric G Proteins ◽  
Kinase C ◽  
Regulate Cell Growth ◽  
Dependent Processes ◽  
Α Subunits

Pertussis toxin (PTX) has been widely used as a reagent to characterize the involvement of heterotrimeric G-proteins in signalling. This toxin catalyses the ADP-ribosylation of specific G-protein α subunits of the Gi family, and this modification prevents the occurrence of the receptorŐG-protein interaction. This review focuses on the biochemical properties and signalling of those G-proteins historically classified as ‘PTX-resistant’ due to the inability of the toxin to influence signalling through them. These G-proteins include members of the Gq and G12 families and one Gi family member, i.e. Gz. Signalling pathways controlled by these G-proteins are well characterized only for Gq family members, which activate specific isoforms of phospholipase C, resulting in increases in intracellular calcium and activation of protein kinase C (PKC), among other responses. While members of the G12 family have been implicated in processes that regulate cell growth, and Gz has been shown to inhibit adenylate cyclase, the specific downstream targets to these G-proteins in vivohave not been clearly established. Since two of these proteins, G12α and Gzα, are excellent substrates for PKC, there is the potential for cross-talk between their signalling and Gq-dependent processes leading to activation of PKC. In tissues that express these G-proteins, a number of guanine-nucleotide-dependent, PTX-resistant, signalling pathways have been defined for which the G-protein involved has not been identified. This review summarizes these pathways and discusses the evidence both for the participation of specific PTX-resistant G-proteins in them and for the regulation of these processes by PKC.

scholarly journals Mutual correlation of excited potentials of the brainwith the level of special physical training of football-players

2008 ◽  
Vol 7 (2) ◽  
pp. 112-114
Author(s):  
L. V. Kapilevich ◽  
Ye. V. Zamoulina
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Physical Training ◽  
First Year ◽  
Football Players ◽  
Training Process ◽  
Mutual Correlation ◽  
Functional Changes ◽  
The Central Nervous System ◽  
The Brain

Decreased amplitude and increased latency of visual and cognitive excited potentials were revealed in football-players in the stage of prima ry special sports training in the first year of their training process. In the second training year, this amplitude is increased and latency is decreased. Forming special physical preparing of the football-players in the stage of primary sports specialization is mutually correlated with functional changes in the central nervous system which manifested in decreased latent period and increased amplitude of excited potentials of the brain.

Some Considerations of the Physical Factor in Delusional States

1939 ◽  
Vol 85 (354) ◽  
pp. 119-125 ◽  
Author(s):  
R. E. Hemphill
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Physical Factor ◽  
Histological Changes ◽  
Functional Changes ◽  
Biological Phenomena ◽  
Physico Chemical ◽  
The Central Nervous System ◽  
The Subject ◽  
The Brain

On the subject of the correlation of neurological lesions with psycho-pathological phenomena, two eminent neuro-histologists, the Werthams, have recently written: “It must be pointed out that in proportion to the extraordinary complexity and differentiation of the finer functions mediated by the central nervous system, histological lesions are very gross. However we may conceive of the functional processes going on in the central nervous system—physiological, physico-chemical, metabolic, electrical, etc.—it should be obvious that only the grossest miscarriages and defects would become morphologically visible. Structural lesions are the effect of functional reactions that are not histologically demonstrable. Physico-chemical changes, metabolic processes, functional changes of blood-vessels, and similar biological phenomena that cannot be micro-histologically demonstrated, precede the anatomically visible lesions which occur only where the processes have attained a certain intensity. What we can demonstrate histologically in the nervous parenchyma is not by any means an adequate basis for the understanding of the quality, intensity or normality of nervous functions. In a patient who dies in the convulsions of tetanus, the anterior horn-cells may reveal nothing abnormal. Even the most minute and complete histological examination of the central nervous system in a case may fail to reveal any evidence of an existing profound disorder of brain function. There are cases of idiocy of the severest type in which no significant histological changes may be demonstrable in the brain.”

scholarly journals Alterations in Cyclic AMP Generation and G Protein Subunits following Transient Ischemia in Gerbil Hippocampus

1995 ◽  
Vol 15 (5) ◽  
pp. 877-885 ◽  
Author(s):  
Kazuhiko Suyama ◽  
Kuniaki Saito ◽  
Guang Chen ◽  
Bai-Shen Pan ◽  
Husseini K. Manji ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
G Protein ◽  
Neuronal Degeneration ◽  
Hippocampal Slices ◽  
Transient Ischemia ◽  
Dependent Protein Kinase ◽  
Protein Subunits ◽  
Dependent Protein ◽  
Generating System ◽  
Α Subunits

We examined alterations in the cyclic AMP generating system and G protein subunits in gerbil hippocampus following 10 min of transient ischemia. In hippocampal slices, basal and isoproterenol- and forskolin-stimulated cyclic AMP accumulations were markedly increased at 6 and 24 h after ischemia. Interestingly, both the inhibition of forskolin-stimulated cyclic AMP and the potentiation of β-adrenoceptor-stimulated cyclic AMP by a γ-aminobutyric acidB receptor agonist were attenuated at these time points. Ischemia did not affect the immuno-labeling of any of the G protein α subunits; only that of β subunits was significantly decreased, by 28.2%, 4 days after ischemia. In contrast, pertussis toxin-catalyzed [32P]ADP ribosylation declined progressively during the late recirculation period, reaching a significant reduction (25.4%) at 6 h after ischemia. These results suggest that ischemia affects the heterotrimeric conformation (αβγ) of Gi/Go during the recirculation period, thereby leading to increased cyclic AMP production. Because cyclic AMP-dependent protein kinase A modulates the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-kainate receptor channels, postischemic sensitization of the cyclic AMP generating system may contribute to neuronal degeneration in the hippocampus.

scholarly journals Development of novel potent ligands for GPR85, an orphan G protein-coupled receptor expressed in the brain

2021 ◽  
Author(s):  
Aya Sakai ◽  
Takeshi Yasui ◽  
Masashi Watanave ◽  
Rine Tatsumi ◽  
Yoshihiko Yamamoto ◽  
...  
Keyword(s):  
G Protein ◽  
G Protein Coupled Receptor ◽  
Orphan Receptors ◽  
Channel Opening ◽  
Ic50 Values ◽  
The Central Nervous System ◽  
Cerebellar Purkinje Cells ◽  
Electrophysiological Technique ◽  
G Protein Coupled ◽  
The Brain

GPR85 is a member of the G protein-coupled receptor and is a super-conserved receptor expressed in the brain sub-family (SREB) with GPR27 and GPR173. These three receptors are orphan receptors; however, their endogenous ligands have not been identified. SREB has garnered the interest of many scientists because it is expressed in the central nervous system and is evolutionarily conserved. In particular, brain mass is reported to be increased and learning and memory are improved in GPR85 knockout mice (Matsumoto et al., 2008). In this study, we characterized newly synthesized compounds using a GPR85-Gsα fusion protein and the [35S]GTPδS binding assay and identified novel GPR85 inverse-agonists with IC50 values of approximately 1 μM. To analyze the neurochemical character of the compounds and investigate the physiological significance of GPR85, we used cerebellar Purkinje cells expressing GPR85 and an electrophysiological technique. Based on the results, the inverse-agonist compound for GPR85 modulated potassium channel opening. Together with the results of previous gene analysis of GPR85, we expect that the development of the GPR85 ligand will provide new insights into a few types of neurological disorders.

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