scholarly journals (H)IF applicable: promotion of neurogenesis by induced HIF-2 signalling after ischaemia

2021 ◽  
Author(s):  
Tristan Leu ◽  
Joachim Fandrey ◽  
Timm Schreiber
Keyword(s):  
Oxygen Supply ◽  
Oxygen Deficiency ◽  
Fine Tuning ◽  
Special Importance ◽  
Hypoxic Stress ◽  
Oxygen Homeostasis ◽  
Ischaemic Brain ◽  
The Neural Network ◽  
Ischaemic Brain Damage ◽  
The Brain

AbstractHIF-2 represents a tissue-specific isoform of the hypoxia-inducible factors (HIFs) which regulate oxygen homeostasis in the cell. In acute oxygen deficiency, HIF transcription factors ensure the timely restoration of adequate oxygen supply. Particularly in medical conditions such as stroke, which have a high mortality risk due to ischaemic brain damage, rapid recovery of oxygen supply is of extraordinary importance. Nevertheless, the endogenous mechanisms are often not sufficient to respond to severe hypoxic stress with restoring oxygenation and fail to protect the tissue. Herein, we analysed murine neurospheres without functioning HIF-2α and found that special importance in the differentiation of neurons can be attributed to HIF-2 in the brain. Other processes, such as cell migration and signal transduction of different signalling pathways, appear to be mediated to some extent via HIF-2 and illustrate the function of HIF-2 in brain remodelling. Without hypoxic stress, HIF-2 in the brain presumably focuses on the fine-tuning of the neural network. However, a therapeutically increase of HIF-2 has the potential to regenerate or replace destroyed brain tissue and help minimize the consequences of an ischaemic stroke.

scholarly journals MiR-7 in Cancer Development

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 325
Author(s):  
Petra Korać ◽  
Mariastefania Antica ◽  
Maja Matulić
Keyword(s):  
Cell Fate ◽  
Dominant Role ◽  
Tumor Development ◽  
Mrna Translation ◽  
Cell Types ◽  
Fine Tuning ◽  
Non Coding Rna ◽  
Tumor Types ◽  
Different Cell Types ◽  
The Brain

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

scholarly journals Imaging Implicit Morphological Processing: Evidence from Hebrew

2010 ◽  
Vol 22 (9) ◽  
pp. 1955-1969 ◽  
Author(s):  
Atira S. Bick ◽  
Ram Frost ◽  
Gadi Goelman
Keyword(s):  
Masked Priming ◽  
Statistical Correlation ◽  
Morphological Processing ◽  
Fine Tuning ◽  
Semantic Transparency ◽  
Lexical Structure ◽  
The Neural Networks ◽  
Distinct Aspect ◽  
The Brain

Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine-tuning of the system to the statistical correlation that exists among orthographic and semantic properties of words? Hebrew provides a unique opportunity to examine morphological processing in the brain because of its rich morphological system. In an fMRI masked priming experiment, we investigated the neural networks involved in implicit morphological processing in Hebrew. In the lMFG and lIFG, activation was found to be significantly reduced when the primes were morphologically related to the targets. This effect was not influenced by the semantic transparency of the morphological prime, and was not found in the semantic or orthographic condition. Additional morphologically related decrease in activation was found in the lIPL, where activation was significantly modulated by semantic transparency. Our findings regarding implicit morphological processing suggest that morphology is an automatic and distinct aspect of visually processing words. These results also coincide with the behavioral data previously obtained demonstrating the central role of morphological processing in reading Hebrew.

Does Motor Learning Occur in the Spinal Cord?

1997 ◽  
Vol 3 (5) ◽  
pp. 287-294 ◽  
Author(s):  
V. Reggie Edgerton ◽  
Roland R. Roy ◽  
Ray De Leon Niranjala Tillakaratne ◽  
John A. Hodgson
Keyword(s):  
Spinal Cord ◽  
Motor Task ◽  
Lumbar Spinal Cord ◽  
Lumbosacral Spinal Cord ◽  
Patterns Of Use ◽  
The Neural Network ◽  
The Central Nervous System ◽  
Network Plasticity ◽  
Lumbar Spinal ◽  
The Brain

It is becoming clear that the plasticity of the sensory-motor networks of the adult mammalian lumbosacral spinal cord is much greater than and is more dependent on the specific patterns of use than has been previously assumed. Using a wide variety of experimental paradigms in which the lumbar spinal cord is isolated from the brain, it has been shown that the lumbosacral spinal cord can learn to execute stepping or standing more successfully if that specific task is practiced. It also appears that the sensory input associated with the motor task and/or the manner in which it is interpreted by the spinal cord are important components of the neural network plasticity. Early evidence suggests that several neurotransmitter systems in the spinal cord, to include glycinergic and GABAergic systems, adapt to repetitive use. These studies extend a growing body of evidence suggesting that memory and learning are widely distributed phenomena within the central nervous system. NEUROSCIENTIST 3:287–294, 1997

Spatiotemporal differences in vascular permeability after ischaemic brain damage

Neuroreport ◽  
2011 ◽  
Vol 22 (9) ◽  
pp. 424-427 ◽  
Author(s):  
Masato Yano ◽  
Naoyuki Kawao ◽  
Yukinori Tamura ◽  
Kiyotaka Okada ◽  
Shigeru Ueshima ◽  
...  
Keyword(s):  
Vascular Permeability ◽  
Brain Damage ◽  
Ischaemic Brain ◽  
Ischaemic Brain Damage

Ischaemic Brain Damage Induced by Rapid Lowering of Arterial Pressure in Hypertension

1984 ◽  
Vol 2 (3) ◽  
pp. 297???304 ◽  
Author(s):  
David I. Graham ◽  
Anne McGeorge ◽  
William Fitch ◽  
John V. Jones ◽  
Eric T. MacKenzie
Keyword(s):  
Arterial Pressure ◽  
Brain Damage ◽  
Ischaemic Brain ◽  
Ischaemic Brain Damage

scholarly journals Hypoxic training as a way of the human brain protection from the damaging effects of oxygen deficiency

2018 ◽  
Vol 9 (4) ◽  
pp. 33-41
Author(s):  
A. Yu. Eroshenko ◽  
N. V. Kochubejnik ◽  
D. V. Shatov ◽  
S. M. Groshilin ◽  
V. N. Sklyarov ◽  
...  
Keyword(s):  
Human Brain ◽  
Alpha Rhythm ◽  
Oxygen Deficiency ◽  
Effective Means ◽  
Brain Protection ◽  
Mental Performance ◽  
Hypoxic Training ◽  
The Brain ◽  
Integral Indicator ◽  
Damaging Effects

Objective:to evaluate the possibilities of normobaric hypoxic training (NHT) in the human brain protection from the damaging effects of oxygen defciency.Materials and methods:the study involved 18 men, aged 19-23 years, who underwent NHT: 15 treatments daily 2-hour stay in a hypoxic gas medium (HGM) having an oxygen content 15.0 ± 0.5% (HGM-15). Beforestarting the NHT (I phase), and afer 1-2 days afer its closure (II stage) were carried hypoxic samples (staying in HGM-15) before and during which the subjects were recorded the electroencephalogram (EEG) and mental performance were evaluated (the «Route» test).Results:when the frst hypoxic test was carried out, the subjects had a decrease in the alpha-rhythm index (on average by 10-15 %, p = 0.013) and its amplitude (by 10-12 %, p = 0.044) compared to the usual environmental conditions. At the same time, the share of low-amplitude slow waves increased (p = 0.019). Te integral indicator of the «Route» test during staying of the subjects in the HGM-15 decreased on average by 18% compared to the usual conditions (p <0.001). Te obtained data testifed about negative influence of staying in HGM -15 on the functioning of the higher parts of the brain. Afer carrying out NHT, all subjects showed a signifcant reduction in the negative reactions of spontaneous EEG to hypoxia: when the sample was repeated, the alpha-rhythm index and its amplitude did not change signifcantly (in comparison with air breathing), signs of excessive slow wave activity were absent. Reduction of the integral indicator of mental performance when staying in HGM-15 amounted to an average of only 6%.Conclusions:NHT in the developed regime is an effective means of the brain protection from the damaging effect of oxygen defciency and can be used in the system of physiological training of specialists to perform tasks of activity in conditions of reduced partial pressure of oxygen.

NF-κB signalling in cerebral ischaemia

2006 ◽  
Vol 34 (6) ◽  
pp. 1291-1294 ◽  
Author(s):  
M. Schwaninger ◽  
I. Inta ◽  
O. Herrmann
Keyword(s):  
Infarct Size ◽  
Brain Damage ◽  
Cerebral Ischaemia ◽  
Neuronal Cell ◽  
Tissue Loss ◽  
Ischaemic Brain ◽  
Ischaemic Brain Damage ◽  
On The Road ◽  
Apoptosis And Inflammation

In acute stroke, neuronal apoptosis and inflammation are considered to be important mechanisms on the road to tissue loss and neurological deficit. Both apoptosis and inflammation depend on gene transcription. We have identified a signalling pathway that regulates transcription of genes involved in apoptosis and inflammation. In a mouse model of focal cerebral ischaemia, there is an induction of the cytokine TWEAK (tumour necrosis factor-like weak inducer of apoptosis) and its membrane receptor Fn14. TWEAK promotes neuronal cell death and activates the transcription factor NF-κB (nuclear factor κB) through the upstream kinase IKK [IκB (inhibitory κB) kinase]. In vivo, IKK is activated in neurons. Neuron-specific deletion of the subunit IKK2 or inhibition of IKK activity reduced the infarct size and neuronal cell loss. A pharmacological inhibitor of IKK also showed neuroprotective properties. IKK-dependent ischaemic brain damage is likely to be mediated by NF-κB, because neuron-specific inhibition of NF-κB through transgenic expression of the NF-κB superrepressor was found to reduce the infarct size. In summary, there is evidence that IKK/NF-κB signalling contributes to ischaemic brain damage and may provide suitable drug targets for the treatment of stroke.

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