scholarly journals The endocrinology of the brain

2018 ◽  
Vol 7 (12) ◽  
pp. R275-R285 ◽  
Author(s):  
Gareth Leng

The brain hosts a vast and diverse repertoire of neuropeptides, a class of signalling molecules often described as neurotransmitters. Here I argue that this description entails a catalogue of misperceptions, misperceptions that feed into a narrative in which information processing in the brain can be understood only through mapping neuronal connectivity and by studying the transmission of electrically conducted signals through chemical synapses. I argue that neuropeptide signalling in the brain involves primarily autocrine, paracrine and neurohormonal mechanisms that do not depend on synaptic connectivity and that it is not solely dependent on electrical activity but on mechanisms analogous to secretion from classical endocrine cells. As in classical endocrine systems, to understand the role of neuropeptides in the brain, we must understand not only how their release is regulated, but also how their synthesis is regulated and how the sensitivity of their targets is regulated. We must also understand the full diversity of effects of neuropeptides on those targets, including their effects on gene expression.

2021 ◽  
Vol 376 (1820) ◽  
pp. 20190757 ◽  
Author(s):  
Aurèle Boussard ◽  
Adrian Fessel ◽  
Christina Oettmeier ◽  
Léa Briard ◽  
Hans-Günther Döbereiner ◽  
...  

The slime mould Physarum polycephalum , an aneural organism, uses information from previous experiences to adjust its behaviour, but the mechanisms by which this is accomplished remain unknown. This article examines the possible role of oscillations in learning and memory in slime moulds. Slime moulds share surprising similarities with the network of synaptic connections in animal brains. First, their topology derives from a network of interconnected, vein-like tubes in which signalling molecules are transported. Second, network motility, which generates slime mould behaviour, is driven by distinct oscillations that organize into spatio-temporal wave patterns. Likewise, neural activity in the brain is organized in a variety of oscillations characterized by different frequencies. Interestingly, the oscillating networks of slime moulds are not precursors of nervous systems but, rather, an alternative architecture. Here, we argue that comparable information-processing operations can be realized on different architectures sharing similar oscillatory properties. After describing learning abilities and oscillatory activities of P. polycephalum , we explore the relation between network oscillations and learning, and evaluate the organism's global architecture with respect to information-processing potential. We hypothesize that, as in the brain, modulation of spontaneous oscillations may sustain learning in slime mould. This article is part of the theme issue ‘Basal cognition: conceptual tools and the view from the single cell’.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 767-768
Author(s):  
Vijay Varma ◽  
Youjin Wang ◽  
Yang An ◽  
Sudhir Varma ◽  
Murat Bilgel ◽  
...  

Abstract While Alzheimer’s disease (AD) and vascular dementia (VaD) may be accelerated by hypercholesterolemia, the mechanisms underlying this association is unclear. Using a novel, 3-step study design we examined the role of cholesterol catabolism in dementia by testing whether 1) the synthesis of the primary cholesterol breakdown products (bile acids (BA)) were associated with neuroimaging markers of dementia; 2) pharmacological modulation of BAs alters dementia risk; and 3) brain BA concentrations and gene expression were associated with AD. We found that higher serum concentrations of BAs are associated with lower brain amyloid deposition, slower WML accumulation, and slower brain atrophy in males. Opposite effects were observed in females. Modulation of BA levels alters risk of incident VaD in males. Altered brain BA signaling at the metabolite and gene expression levels occurs in AD. Dysregulation of peripheral cholesterol catabolism and BA synthesis may impact dementia pathogenesis through signaling pathways in the brain.


2016 ◽  
Vol 371 (1688) ◽  
pp. 20150114 ◽  
Author(s):  
Nancy G. Forger

Circumstantial evidence alone argues that the establishment and maintenance of sex differences in the brain depend on epigenetic modifications of chromatin structure. More direct evidence has recently been obtained from two types of studies: those manipulating a particular epigenetic mechanism, and those examining the genome-wide distribution of specific epigenetic marks. The manipulation of histone acetylation or DNA methylation disrupts the development of several neural sex differences in rodents. Taken together, however, the evidence suggests there is unlikely to be a simple formula for masculine or feminine development of the brain and behaviour; instead, underlying epigenetic mechanisms may vary by brain region or even by dependent variable within a region. Whole-genome studies related to sex differences in the brain have only very recently been reported, but suggest that males and females may use different combinations of epigenetic modifications to control gene expression, even in cases where gene expression does not differ between the sexes. Finally, recent findings are discussed that are likely to direct future studies on the role of epigenetic mechanisms in sexual differentiation of the brain and behaviour.


Biomeditsina ◽  
2019 ◽  
pp. 12-22
Author(s):  
N. V. Petrova

It is shown that the level of the Lep gene expression is a marker for B/Ks-Leprᵈᵇ/+ mice, which line serves as an optimal model for describing metabolic syndrome (MS) in preclinical studies. Mice were transplanted with cultured isogenic bone marrow cells (BMC) from heterozygous db/+ donors. The recipients were divided into two groups according to an early or advanced stage of MS development. We analyzed the expression of the Lep gene on the 3rd, 8th and 14th day following the administration of stem BMCs in the brain, liver and pancreas cells by polymerase chain reaction (PCR) in real time. The Lep gene expression was evaluated in terms of the number of cDNA copies. According to our data, leptin is a complete regulator of metabolic processes due to its effect on the hypothalamus, which, together with the hippocampus, controls the production of acetylcholine and insulin in the brain. We have proven the role of the Lep gene as a quantitative criterion for evaluating the effi cacy of a cell therapy in MS.


Author(s):  
Ebrahim Oshni Alvandi

One way to evaluate cognitive processes in living or nonliving systems is by using the notion of “information processing”. Emotions as cognitive processes orient human beings to recognize, express and display themselves or their wellbeing through dynamical and adaptive form of information processing. In addition, humans behave or act emotionally in an embodied environment. The brain embeds symbols, meaning and purposes for emotions as well. So any model of natural or autonomous emotional agents/systems needs to consider the embodied features of emotions that are processed in an informational channel of the brain or a processing system. This analytical and explanatory study described in this chapter uses the pragmatic notion of information to develop a theoretical model for emotions that attempts to synthesize some essential aspects of human emotional processing. The model holds context-sensitive and purpose-based features of emotional pattering in the brain. The role of memory is discussed and an idea of control parameters that have roles in processing environmental variables in emotional patterning is introduced.


2006 ◽  
Vol 36 (8) ◽  
pp. 705-722 ◽  
Author(s):  
Alan St Clair Gibson ◽  
Estelle V Lambert ◽  
Laurie H G Rauch ◽  
Ross Tucker ◽  
Denise A Baden ◽  
...  

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 574
Author(s):  
Marta Kaczor-Kamińska ◽  
Piotr Sura ◽  
Maria Wróbel

The investigations showed changes of the cystathionine γ-lyase (CTH), 3-mercaptopyruvate sulfurtransferase (MPST) and rhodanese (TST) activity and gene expression in the brain, heart, liver, kidney, skeletal muscles and testes in frogs Pelophylax ridibundus, Xenopus laevis and Xenopus tropicalis in response to Pb2+, Hg2+ and Cd2+ stress. The results were analyzed jointly with changes in the expression of selected antioxidant enzymes (cytoplasmic and mitochondrial superoxide dismutase, glutathione peroxidase, catalase and thioredoxin reducatase) and with the level of malondialdehyde (a product of lipid peroxidation). The obtained results allowed for confirming the role of sulfurtransferases in the antioxidant protection of tissues exposed to heavy metal ions. Our results revealed different transcriptional responses of the investigated tissues to each of the examined heavy metals. The CTH, MPST and TST genes might be regarded as heavy metal stress-responsive. The CTH gene expression up-regulation was confirmed in the liver (Pb2+, Hg2+, Cd2+) and skeletal muscle (Hg2+), MPST in the brain (Pb2+, Hg2+), kidney (Pb2+, Cd2+), skeletal muscle (Pb2+, Hg2+,Cd2+) and TST in the brain (Pb2+) and kidney (Pb2+, Hg2+, Cd2+). Lead, mercury and cadmium toxicity was demonstrated to affect the glutathione (GSH) and cysteine levels, the concentration ratio of reduced to oxidized glutathione ([GSH]/[GSSG]) and the level of sulfane sulfur-containing compounds, which in case of enhanced reactive oxygen species generation can reveal their antioxidative properties. The present report is the first to widely describe the role of the sulfane sulfur/H2S generating enzymes and the cysteine/glutathione system in Pb2+, Hg2+ and Cd2+ stress in various frog tissues, and to explore the mechanisms mediating heavy metal-related stress.


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