scholarly journals Role of GABA-A and GABA-B receptors of the brain in the hypothalamo-pituitary-testicular regulation by the negative feedback mechanism

1995 ◽  
Vol 41 (4) ◽  
pp. 36-38
Author(s):  
Ye. V. V. Naumenko ◽  
A. V. Amikishiyeva ◽  
L. I. Serova

The role of gamma-aminobutyric acid (GABA) of the brain and its receptors in the hypothalamo-pituitary-testicular (HPT) regulation by the negative feedback mechanism was for the first time studied in sham-operated and unilaterally castrated adult Wister rats. Increased level of GABA in the central nervous system following an injection of GABA transaminase inhibitor, aminoacetic acid, into the lateral ventricle of the brain was associated with activation of a compensatory increase of testosterone level in the blood, caused by unilateral castration. GABA effect is mediated through the receptors. Muscimol stimulation of GABA-A receptors of the central nervous system activated and their blocking with bicucullin inhibited a compensatory increase of testosterone level in the blood caused by hemicastration. Baclofen stimulation of cerebral GABA-B receptors was associated with an inhibition and their saclofen blocking with stimulation of the level of male sex steroid hormone in the blood following unilateral castration. A conclusion is made about participation of GABAergic mechanisms of the brain in the regulation of HPT function via the negative feedback mechanism

Psychiatry ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 125-134
Author(s):  
E. F. Vasilyeva ◽  
O. S. Brusov

Background: at present, the important role of the monocyte-macrophage link of immunity in the pathogenesis of mental diseases has been determined. In the first and second parts of our review, the cellular and molecular mechanisms of activation of monocytes/macrophages, which secreting proinflammatory CD16 receptors, cytokines, chemokines and receptors to them, in the development of systemic immune inflammation in the pathogenesis of somatic diseases and mental disorders, including schizophrenia, bipolar affective disorder (BAD) and depression were analyzed. The association of high levels of proinflammatory activity of monocytes/macrophages in patients with mental disorders with somatic comorbidity, including immune system diseases, is shown. It is known that proinflammatory monocytes of peripheral blood, as a result of violation of the integrity of the hematoencephalic barrier can migrate to the central nervous system and activate the resident brain cells — microglia, causing its activation. Activation of microglia can lead to the development of neuroinammation and neurodegenerative processes in the brain and, as a result, to cognitive disorders. The aim of review: to analyze the results of the main scientific studies concerning the role of cellular and molecular mechanisms of peripheral blood monocytes interaction with microglial cells and platelets in the development of neuroinflammation in the pathogenesis of mental disorders, including Alzheimer’s disease (AD). Material and methods: keywords “mental disorders, AD, proinflammatory monocytes, microglia, neuroinflammation, cytokines, chemokines, cell adhesion molecules, platelets, microvesicles” were used to search for articles of domestic and foreign authors published over the past 30 years in the databases PubMed, eLibrary, Science Direct and EMBASE. Conclusion: this review analyzes the results of studies which show that monocytes/macrophages and microglia have similar gene expression profiles in schizophrenia, BAD, depression, and AD and also perform similar functions: phagocytosis and inflammatory responses. Monocytes recruited to the central nervous system stimulate the increased production of proinflammatory cytokines IL-1, IL-6, tumor necrosis factor alpha (TNF-α), chemokines, for example, MCP-1 (Monocyte chemotactic protein-1) by microglial cells. This promotes the recruitment of microglial cells to the sites of neuronal damage, and also enhances the formation of the brain protein beta-amyloid (Aβ). The results of modern studies are presented, indicating that platelets are involved in systemic inflammatory reactions, where they interact with monocytes to form monocyte-platelet aggregates (MTA), which induce the activation of monocytes with a pro inflammatory phenotype. In the last decade, it has been established that activated platelets and other cells of the immune system, including monocytes, detached microvesicles (MV) from the membrane. It has been shown that MV are involved as messengers in the transport of biologically active lipids, cytokines, complement, and other molecules that can cause exacerbation of systemic inflammatory reactions. The presented review allows us to expand our knowledge about the cellular and molecular aspects of the interaction of monocytes/macrophages with microglial cells and platelets in the development of neuroinflammation and cognitive decline in the pathogenesis of mental diseases and in AD, and also helps in the search for specific biomarkers of the clinical severity of mental disorder in patients and the prospects for their response to treatment.


Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2340
Author(s):  
Hannah E. Henson ◽  
Michael R. Taylor

The spliceosome consists of accessory proteins and small nuclear ribonucleoproteins (snRNPs) that remove introns from RNA. As splicing defects are associated with degenerative conditions, a better understanding of spliceosome formation and function is essential. We provide insight into the role of a spliceosome protein U4/U6.U5 tri-snRNP-associated protein 1, or Squamous cell carcinoma antigen recognized by T-cells (Sart1). Sart1 recruits the U4.U6/U5 tri-snRNP complex to nuclear RNA. The complex then associates with U1 and U2 snRNPs to form the spliceosome. A forward genetic screen identifying defects in choroid plexus development and whole-exome sequencing (WES) identified a point mutation in exon 12 of sart1 in Danio rerio (zebrafish). This mutation caused an up-regulation of sart1. Using RNA-Seq analysis, we identified additional upregulated genes, including those involved in apoptosis. We also observed increased activated caspase 3 in the brain and eye and down-regulation of vision-related genes. Although splicing occurs in numerous cells types, sart1 expression in zebrafish was restricted to the brain. By identifying sart1 expression in the brain and cell death within the central nervous system (CNS), we provide additional insights into the role of sart1 in specific tissues. We also characterized sart1’s involvement in cell death and vision-related pathways.


1993 ◽  
Vol 175 (1) ◽  
pp. 305-311
Author(s):  
H. Le Corronc ◽  
B. Hue

Biochemical studies of the central nervous system (CNS) of locusts (Breer and Knipper, 1984; Knipper and Breer, 1988) have provided evidence for a muscarinic negative feedback mechanism in which muscarinic antagonists and agonists, respectively, enhance and decrease the acetylcholine (ACh) output. More recently, this inhibitory action of presynaptic muscarinic acetylcholine receptors (mAChrs) has been demonstrated in cockroach (Hue et al. 1989; Le Corronc et al. 1991) and in tobacco hornworm (Trimmer and Weeks, 1989) using electrophysiological methods. However, in insects, most experiments have not been performed under physiological conditions but in the presence of acetylcholinesterase inhibitors or exogenous agonists. The aim of this study was to determine whether the release of ACh at a central synapse in the cockroach, Periplaneta americana, could be modulated by endogenous ACh acting on presynaptic muscarinic receptors.


2019 ◽  
Vol 10 (1) ◽  
pp. 63-71
Author(s):  
Aleksandr A. Kalinkin ◽  
Alexey G. Vinokurov ◽  
Olga N. Kalinkina ◽  
Alexander S. Ilinykh ◽  
Andrey A. Bocharov ◽  
...  

The technique of deep brain stimulation is used to treat patients with various diseases of the central nervous system who are not amenable to conservative therapy, while open interventions in them are associated with a high risk of complications. In the review, we evaluate the efficiency of the deep stimulation of different regions of the brain in some pharmacoresistant forms of diseases.


1963 ◽  
Vol 4 (2) ◽  
pp. 118-130 ◽  
Author(s):  
Hideo UEDA ◽  
Akiyuki YAMADA ◽  
Hitoshi GOTO ◽  
Iwao ITO ◽  
Yutaka TAKABATAKE ◽  
...  

1937 ◽  
Vol 33 (5) ◽  
pp. 523-532
Author(s):  
L. S. Stern

Evaluation of the results obtained in the study of the effect of cerebrospinal fluid on various physiological systems is complicated by the fact that the composition of the cerebrospinal fluid depends to a large extent on the state of the blood-brain barrier, and thus reflects not only a certain physiological state of the central nervous system. There is no doubt that the metabolic products of the brain, secreted into the cerebrospinal fluid, exert their effect not only on the activity of various parts of the brain and on the coordination of their functions, but due to the rapid transition of these substances from the cerebrospinal fluid into the general circulation, they also affect as a humoral a factor on the function of other physiological systems, as it was revealed in a number of experiments carried out in recent years in our laboratories. For example, it turned out that under various influences (direct irritation of the central nervous system in experimental epilepsy, irritation of the sensory nerves associated with severe pain, traumatic shock, toxemic or chemical shock, as well as starvation, prolonged insomnia, etc.) - substances appear in the cerebrospinal fluid that affect the state and activity of the cardiovascular system, the tone of smooth muscles, the excitability of the central nervous system, etc. These are the results of the work of our employees: Zeitlin, Weiss, Harles, Voskresensky, Gromakovskaya , Bazarova, Gotsman, Komarova and others. Work in this direction continues at the present time.


Development ◽  
2001 ◽  
Vol 128 (10) ◽  
pp. 1757-1769 ◽  
Author(s):  
C. Olivier ◽  
I. Cobos ◽  
E.M. Perez Villegas ◽  
N. Spassky ◽  
B. Zalc ◽  
...  

Oligodendrocytes are the myelin-forming cells in the central nervous system. In the brain, oligodendrocyte precursors arise in multiple restricted foci, distributed along the caudorostral axis of the ventricular neuroepithelium. In chick embryonic hind-, mid- and caudal forebrain, oligodendrocytes have a basoventral origin, while in the rostral fore-brain oligodendrocytes emerge from alar territories (Perez Villegas, E. M., Olivier, C., Spassky, N., Poncet, C., Cochard, P., Zalc, B., Thomas, J. L. and Martinez, S. (1999) Dev. Biol. 216, 98–113). To investigate the respective territories colonized by oligodendrocyte progenitor cells that originate from either the basoventral or alar foci, we have created a series of quail-chick chimeras. Homotopic chimeras demonstrate clearly that, during embryonic development, oligodendrocyte progenitors that emerge from the alar anterior entopeduncular area migrate tangentially to invade the entire telencephalon, whereas those from the basal rhombomeric foci show a restricted rostrocaudal distribution and colonize only their rhombomere of origin. Heterotopic chimeras indicate that differences in the migratory properties of oligodendroglial cells do not depend on their basoventral or alar ventricular origin. Irrespective of their origin (basal or alar), oligodendrocytes migrate only short distances in the hindbrain and long distances in the prosencephalon. Furthermore, we provide evidence that, in the developing chick brain, all telencephalic oligodendrocytes originate from the anterior entopeduncular area and that the prominent role of anterior entopeduncular area in telencephalic oligodendrogenesis is conserved between birds and mammals.


Author(s):  
Era Gorica ◽  
Vincenzo Calderone

: Neuroinflammation is characterized by dysregulated inflammatory responses localized within the brain and spinal cord. Neuroinflammation plays a pivotal role in the onset of several neurodegenerative disorders and is considered a typical feature of these disorders. Microglia perform primary immune surveillance and macrophage-like activities within the central nervous system. Activated microglia are predominant players in the central nervous system response to damage related to stroke, trauma, and infection. Moreover, microglial activation per se leads to a proinflammatory response and oxidative stress. During the release of cytokines and chemokines, cyclooxygenases and phospholipase A2 are stimulated. Elevated levels of these compounds play a significant role in immune cell recruitment into the brain. Cyclic phospholipase A2 plays a fundamental role in the production of prostaglandins by releasing arachidonic acid. In turn, arachidonic acid is biotransformed through different routes into several mediators that are endowed with pivotal roles in the regulation of inflammatory processes. Some experimental models of neuroinflammation exhibit an increase in cyclic phospholipase A2, leukotrienes, and prostaglandins such as prostaglandin E2, prostaglandin D2, or prostacyclin. However, findings on the role of the prostacyclin receptors have revealed that their signalling suppresses Th2-mediated inflammatory responses. In addition, other in vitro evidence suggests that prostaglandin E2 may inhibit the production of some inflammatory cytokines, attenuating inflammatory events such as mast cell degranulation or inflammatory leukotriene production. Based on these conflicting experimental data, the role of arachidonic acid derivatives in neuroinflammation remains a challenging issue.


Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 562
Author(s):  
Nathan A. Shlobin ◽  
Meirav Har-Even ◽  
Ze’ev Itsekson-Hayosh ◽  
Sagi Harnof ◽  
Chaim G. Pick

Thrombin is a Na+-activated allosteric serine protease of the chymotrypsin family involved in coagulation, inflammation, cell protection, and apoptosis. Increasingly, the role of thrombin in the brain has been explored. Low concentrations of thrombin are neuroprotective, while high concentrations exert pathological effects. However, greater attention regarding the involvement of thrombin in normal and pathological processes in the central nervous system is warranted. In this review, we explore the mechanisms of thrombin action, localization, and functions in the central nervous system and describe the involvement of thrombin in stroke and intracerebral hemorrhage, neurodegenerative diseases, epilepsy, traumatic brain injury, and primary central nervous system tumors. We aim to comprehensively characterize the role of thrombin in neurological disease and injury.


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