scholarly journals Ventromedial Arcuate Nucleus Communicates Peripheral Metabolic Information to the Suprachiasmatic Nucleus

Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 283-294 ◽  
Author(s):  
Chun-Xia Yi ◽  
Jan van der Vliet ◽  
Jiapei Dai ◽  
Guangfu Yin ◽  
Liqiang Ru ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Suprachiasmatic Nucleus ◽  
Energy Homeostasis ◽  
Arcuate Nucleus ◽  
Circumventricular Organs ◽  
Systemic Injection ◽  
Neural Connections ◽  
The Central Nervous System ◽  
Functional Pathway

The arcuate nucleus (ARC) is crucial for the maintenance of energy homeostasis as an integrator of long- and short-term hunger and satiety signals. The expression of receptors for metabolic hormones, such as insulin, leptin, and ghrelin, allows ARC to sense information from the periphery and signal it to the central nervous system. The ventromedial ARC (vmARC) mainly comprises orexigenic neuropeptide agouti-related peptide and neuropeptide Y neurons, which are sensitive to circulating signals. To investigate neural connections of vmARC within the central nervous system, we injected the neuronal tracer cholera toxin B into vmARC. Due to variation of injection sites, tracer was also injected into the subependymal layer of the median eminence (seME), which showed similar projection patterns as the vmARC. We propose that the vmARC forms a complex with the seME, their reciprocal connections with viscerosensory areas in brain stem, and other circumventricular organs, suggesting the exchange of metabolic and circulating information. For the first time, the vmARC-seME was shown to have reciprocal interaction with the suprachiasmatic nucleus (SCN). Activation of vmARC neurons by systemic administration of the ghrelin mimetic GH-releasing peptide-6 combined with SCN tracing showed vmARC neurons to transmit feeding related signals to the SCN. The functionality of this pathway was demonstrated by systemic injection of GH-releasing peptide-6, which induced Fos in the vmARC and resulted in a reduction of about 40% of early daytime Fos immunoreactivity in the SCN. This observation suggests an anatomical and functional pathway for peripheral hormonal feedback to the hypothalamus, which may serve to modulate the activity of the SCN.

Hormonal-sympathetic interactions in long-term regulation of arterial pressure: an hypothesis

1995 ◽  
Vol 268 (6) ◽  
pp. R1343-R1358 ◽  
Author(s):  
V. L. Brooks ◽  
J. W. Osborn
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Arterial Pressure ◽  
Plasma Concentrations ◽  
Circumventricular Organs ◽  
Feedback Signal ◽  
Salt Loading ◽  
Alternate Model ◽  
The Central Nervous System

The importance of the sympathetic nervous system in short-term regulation of arterial pressure is well accepted. However, the question of whether neural systems participate in long-term control of pressure has been debated for decades and remains unresolved. The principal argument against such a control system is that arterial baroreceptors adapt to sustained changes in arterial pressure. In addition, denervation of baroreceptors has minimal to no effect on basal levels of arterial pressure chronically. This argument assumes, however, that baroreceptors provide the primary chronic feedback signal to the central nervous system. An alternate model is proposed in which circulating hormones, primarily arginine vasopressin and angiotensin II, provide a long-term afferent signal to the central nervous system via binding to specific receptors in central sites lacking a blood-brain barrier (circumventricular organs). Studies suggest that the release of the hormones and the sympathetic response to alterations in their plasma concentrations are nonadaptive but may be gated by baroreceptor input. Evidence that this "hormonal-sympathetic reflex" model may explain the long-term alterations in sympathetic activity in response to chronic salt depletion and salt loading as well as congestive heart failure is presented. Finally, the role of an impaired hormonal sympathetic reflex in hypertension, specifically salt-dependent hypertension, is discussed.

Brain Glucose Sensing, Counterregulation, and Energy Homeostasis

Physiology ◽  
2007 ◽  
Vol 22 (4) ◽  
pp. 241-251 ◽  
Author(s):  
Nell Marty ◽  
Michel Dallaporta ◽  
Bernard Thorens
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Energy Homeostasis ◽  
Critical Role ◽  
Glucose Sensing ◽  
Neuronal Circuits ◽  
Brain Glucose ◽  
The Central Nervous System

Neuronal circuits in the central nervous system play a critical role in orchestrating the control of glucose and energy homeostasis. Glucose, beside being a nutrient, is also a signal detected by several glucose-sensing units that are located at different anatomical sites and converge to the hypothalamus to cooperate with leptin and insulin in controlling the melanocortin pathway.

scholarly journals Sex differences in the effects of androgens acting in the central nervous system on metabolism

2016 ◽  
Vol 18 (4) ◽  
pp. 415-424 ◽  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Central Nervous System ◽  
Nervous System ◽  
Metabolic Regulation ◽  
Energy Homeostasis ◽  
Sexually Dimorphic ◽  
Metabolic Homeostasis ◽  
The Central Nervous System

One of the most sexually dimorphic aspects of metabolic regulation is the bidirectional modulation of glucose and energy homeostasis by testosterone in males and females. Testosterone deficiency predisposes men to metabolic dysfunction, with excess adiposity, insulin resistance, and type 2 diabetes, whereas androgen excess predisposes women to insulin resistance, adiposity, and type 2 diabetes. This review discusses how testosterone acts in the central nervous system, and especially the hypothalamus, to promote metabolic homeostasis or dysfunction in a sexually dimorphic manner. We compare the organizational actions of testosterone, which program the hypothalamic control of metabolic homeostasis during development, and the activational actions of testosterone, which affect metabolic function after puberty. We also discuss how the metabolic effect of testosterone is centrally mediated via the androgen receptor.

scholarly journals SARS-CoV-2 Impact on the Central Nervous System: Are Astrocytes and Microglia Main Players or Merely Bystanders?

2020 ◽  
Author(s):  
Veronica Murta ◽  
Alejandro Villarreal ◽  
Alberto Javier Ramos
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Clinical Manifestations ◽  
Signs And Symptoms ◽  
Experimental Models ◽  
Circumventricular Organs ◽  
Target Cells ◽  
Neurological Manifestations ◽  
Cns Inflammation ◽  
The Central Nervous System

With confirmed COVID-19 cases surpassing the 8.5 million mark around the globe, there is an imperative need to deepen the efforts from the international scientific community to gain comprehensive understanding of SARS-CoV-2. Although the main clinical manifestations are associated with respiratory or intestinal symptoms, reports of specific and non-specific neurological signs and symptoms, both at presentation or during the course of the acute phase, are increasing. Approximately 25-40% of the patients present neurological symptoms. The etiology of these neurological manifestations remains obscure, and probably involves several direct pathways, not excluding the direct entry of the virus to the Central Nervous System (CNS) through the olfactory epithelium, circumventricular organs, or disrupted blood-brain barrier (BBB). Furthermore, neuroinflammation might occur in response to the strong systemic cytokine storm described for COVID-19, or due to dysregulation of the CNS angiotensin system. Descriptions of neurological manifestations in patients in the previous coronavirus (CoV) outbreaks have been numerous for the SARS-CoV and lesser for MERS-CoV. Strong evidence from patients and experimental models suggests that some human variants of CoV have the ability to reach the CNS and that neurons, astrocytes and/or microglia can be target cells for CoV. A growing body of evidence shows that astrocytes and microglia have a major role in neuroinflammation, responding to local CNS inflammation and/or to dysbalanced peripheral inflammation. This is another potential mechanism for SARS-CoV-2 damage to the CNS. In this work we will summarize the known neurological manifestations of SARS-CoV-2, SARS-CoV and MERS-CoV, explore the potential role for astrocytes and microglia in the infection and neuroinflammation, and compare them with the previously described human and animal CoV that showed neurotropism. We also propose possible underlying mechanisms by focusing on our knowledge of glia, neurons, and their dynamic intricate communication with the immune system.

scholarly journals Nonlesions, Unusual Cell Types, and Postmortem Artifacts in the Central Nervous System of Domestic Animals

2012 ◽  
Vol 50 (1) ◽  
pp. 122-143 ◽  
Author(s):  
P. Wohlsein ◽  
U. Deschl ◽  
W. Baumgärtner
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Area Postrema ◽  
Morphological Changes ◽  
Subcommissural Organ ◽  
Cell Types ◽  
Domestic Animals ◽  
Circumventricular Organs ◽  
Polyglucosan Bodies ◽  
The Central Nervous System

In the central nervous system (CNS) of domestic animals, numerous specialized normal structures, unusual cell types, findings of uncertain or no significance, artifacts, and various postmortem alterations can be observed. They may cause confusion for inexperienced pathologists and those not specialized in neuropathology, leading to misinterpretations and wrong diagnoses. Alternatively, changes may mask underlying neuropathological processes. “Specialized structures” comprising the hippocampus and the circumventricular organs, including the vascular organ of the lamina terminalis, subfornical organ, subcommissural organ, pineal gland, median eminence/neurohypophyseal complex, choroid plexus, and area postrema, are displayed. Unusual cell types, including cerebellar external germinal cells, CNS progenitor cells, and Kolmer cells, are presented. In addition, some newly recognized cell types as of yet incompletely understood significance and functionality, such as synantocytes and aldynoglia, are introduced and described. Unusual reactive astrocytes in cats, central chromatolysis, neuronal vacuolation, spheroids, spongiosis, satellitosis, melanosis, neuromelanin, lipofuscin, polyglucosan bodies, and psammoma bodies may represent incidental findings of uncertain or no significance and should not be confused with significant microscopic changes. Auto- and heterolysis as well as handling and histotechnological processing may cause postmortem morphological changes of the CNS, including vacuolization, cerebellar conglutination, dark neurons, Buscaino bodies, freezing, and shrinkage artifacts, all of which have to be differentiated from genuine lesions. Postmortem invasion of micro-organisms should not be confused with intravital infections. Awareness of these different changes and their recognition are a prerequisite for identifying genuine lesions and may help to formulate a professional morphological and etiological diagnosis.

scholarly journals Vestibular neuromodulation in neurology and psychiatry

2018 ◽  
pp. 29-35 ◽  
Author(s):  
A. G. Naryshkin ◽  
I. V. Galanin ◽  
V. L. Kozlovskii ◽  
V. Yu. Popov
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Vestibular System ◽  
Neurological Disorders ◽  
State Of The Art ◽  
Drug Resistant ◽  
Peripheral Part ◽  
Neural Connections ◽  
The Central Nervous System ◽  
Chemical Stimuli

Te paper overviews the state of the art in one of the most rapidly developing areas of treatment of various drug-resistant diseases of the central nervous system. Different methods of vestibular neuromodulation and their comparative efcacy in the treatment of mental and neurological disorders are described. All those methods are based on neuroplasticity activation by means of application of physical, electrical or chemical stimuli on the peripheral part of the vestibular system, which leads to the restructuring of neural connections in the brainstem and in the midbrain.

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