Cortical ablation induces time‐dependent changes in rat pituitary somatotrophs and upregulates growth hormone receptor expression in the injured cortex

Lavrnja, Irena; Ajdžanović, Vladimir; Trifunović, Svetlana; Savić, Danijela; Milošević, Verica; Stojiljković, Mirjana; Peković, Sanja

doi:10.1002/jnr.23408

Cited by 7 publications

(5 citation statements)

References 47 publications

(64 reference statements)

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“…Therefore, it could be possible that these nestin-expressing neurons were already present and commenced to reexpress nestin after GH treatment and rehabilitative therapy, perhaps because of increased GH-receptor (GHR) expression and/or plasticity events leading to the remodeling of the undamaged contralateral motor cortex after the cortical ablation. We did not analyze whether GHR expression was upregulated in the contralateral intact cortex, but it has been recently described that during recovery from brain injury, there is an upregulation of GHR that may play a role in neuronal arborization and glial proliferation in the injured cortex [ 56 ].…”

Section: Discussionmentioning

confidence: 99%

Motor Improvement of Skilled Forelimb Use Induced by Treatment with Growth Hormone and Rehabilitation Is Dependent on the Onset of the Treatment after Cortical Ablation

et al. 2018

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We previously demonstrated that the administration of GH immediately after severe motor cortex injury, in rats, followed by rehabilitation, improved the functionality of the affected limb and reexpressed nestin in the contralateral motor cortex. Here, we analyze whether these GH effects depend on a time window after the injury and on the reexpression of nestin and actin. Injured animals were treated with GH (0.15 mg/kg/day) or vehicle, at days 7, 14, and 35 after cortical ablation. Rehabilitation was applied at short and long term (LTR) after the lesion and then sacrificed. Nestin and actin were analyzed by immunoblotting in the contralateral motor cortex. Giving GH at days 7 or 35 after the lesion, but not 14 days after it, led to a remarkable improvement in the functionality of the affected paw. Contralateral nestin and actin reexpression was clearly higher in GH-treated animals, probably because compensatory brain plasticity was established. GH and immediate rehabilitation are key for repairing brain injuries, with the exception of a critical time period: GH treatment starting 14 days after the lesion. Our data also indicate that there is not a clear plateau in the recovery from a brain injury in agreement with our data in human patients.

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Section: Discussionmentioning

confidence: 99%

Motor Improvement of Skilled Forelimb Use Induced by Treatment with Growth Hormone and Rehabilitation Is Dependent on the Onset of the Treatment after Cortical Ablation

et al. 2018

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“…Astrocytes are special giant cells in brain interstitial fluids that play a major role in β amyloid and tau cleanup. Their activity is increased by growth hormone and insulinlike growth factor [48]. In adults, slow-wave sleep is the principal stage of sleep in which growth hormone secretion takes place.…”

Section: ) Accumulations Of Extracellular β Amyloid Protein Plaques mentioning

confidence: 99%

Mechanisms of Association of Sleep and Metabolic Syndrome

Smiley¹,

Wolter²,

Nissan³

2019

J Med - Clin Res & Rev

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There is a U-shaped association between sleep duration and risk of metabolic syndrome. The related mechanisms can be grouped into two categories: I. Too little slow-wave sleep; II. Too much REM sleep. Too little slow-wave sleep. 1) Stage 3 is the most crucial sleep stage because growth hormone (GH) and GH releasing hormone (GHRH) are released during this stage. They induce fat burning, bone building, and general repair and regeneration. The greater the volume of GH and GHRH released, the more restorative the sleep. The longest part of stage 3 in sleep takes place before midnight. Delayed sleep onset until midnight or later, would suppress the largest GH pulse. 2) Sleep restriction induces high levels of ghrelin and low levels of leptin. Ghrelin stimulates appetite whereas leptin does the reverse. 3) Advanced glycation end products (AGEs) are significantly increased in chronic sleep insufficiency and are also associated with insulin resistance in males with chronic sleep insufficiency. 4) Sleep insufficiency increases sympathetic activity and pro-inflammatory cytokines, both of which increase insulin resistance. 5) Accumulations of extracellular β amyloid protein plaques and intracellular tau neurofibrillary tangles in brain tissues start immediately after one night of sleep insufficiency. These plaques and tangles are neurotoxins that potentiate each other's destructive effects on the structures and functions of brain cells and cause neuronal death. The consequence is a global decrease in cognition and decision making, manifested in increased consumption of fatty foods and unhealthy snacks in late sleepers. 6) High levels of β amyloid and proteins might lead to sleep fragmentation, worsening of sleep quality and daytime somnolence. Concentration will be more difficult, and performance will be reduced. 7) Astrocytes are special giant cells in brain interstitial fluids that play a major role in β amyloid and tau cleanup. Their activity is increased by growth hormone. As a result, slow-wave sleep insufficiency may lead to impaired peripheral clearance of β amyloid and tau proteins predisposing the brain to Alzheimer's disease. Too much REM sleep. 1) The REM stage is the dreaming stage. The level of cortisol starts to rise in the middle of night based on circadian rhythm, and peaks in the morning. Cortisol is the fight or flight hormone, equipping the individual both to meet the demands of daily life and to handle stressful situations. It stimulates the release of epinephrine and norepinephrine. These hormones increase heart rate and blood pressure as they prepare the body to initiate activity quickly. These reactions occur on top of heart rate variability and a rise in blood pressure induced by REM sleep. If the individual wakes up early in the morning, he will use the cortisol properly to prepare for the new day. If instead he or she remains asleep, there will be no physical activity, and the cortisol levels that are normal for a person who is awake will be high levels for the one who is asleep. Then, the sleeper m...

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“…Growth hormone releasing hormone (GHRH) also promotes the activity of astrocytes in the brain, which means that during SWS sleep, astrocytes are more active in cleaning up β amyloid and tau proteins [ 80 , 81 , 82 ]. Those with an evening chronotype thus will have suboptimal levels of clearance of β amyloid and tau protein due to the decreased duration of SWS.…”

Section: Sleep Chronotype and Metabolic Syndromementioning

confidence: 99%

“…Quality sleep is important for maintaining neural health. As discussed previously, it is during SWS that misfolded neurotoxin proteins are cleared from neural tissue [ 80 , 81 ]. This is because GHRH released during SWS helps promote astrocyte activity in the brain [ 79 ].…”

Section: Contributions Of Inadequate Sleep Health On Other Chronic Di...mentioning

confidence: 99%

Healthy Sleep Every Day Keeps the Doctor Away

Feingold

Smiley

2022

IJERPH

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When one considers the big picture of their health, sufficient sleep may often go overlooked as a keystone element in this picture. Insufficient sleep in either quality or duration is a growing problem for our modern society. It is essential to look at what this means for our health because insufficient sleep increases our risks of innumerable lifechanging diseases. Beyond increasing the risk of developing these diseases, it also makes the symptoms and pathogenesis of many diseases worse. Additionally, consistent quality sleep can not only improve our physical health but has also been shown to improve mental health and overall quality of life. Substandard sleep health could be a root cause for numerous issues individuals may be facing in their lives. It is essential that physicians take the time to learn about how to educate their patients on sleep health and try to work with them on an individual level to help motivate lifestyle changes. Facilitating access to sleep education for their patients is one way in which physicians can help provide patients with the tools to improve their sleep health. Throughout this paper, we will review the mechanisms behind the relationship between insufficient sleep health and chronic disease and what the science says about how inadequate sleep health negatively impacts the overall health and the quality of our lives. We will also explain the lifechanging effects of sufficient sleep and how we can help patients get there.

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Cortical ablation induces time‐dependent changes in rat pituitary somatotrophs and upregulates growth hormone receptor expression in the injured cortex

Cited by 7 publications

References 47 publications

Motor Improvement of Skilled Forelimb Use Induced by Treatment with Growth Hormone and Rehabilitation Is Dependent on the Onset of the Treatment after Cortical Ablation

Motor Improvement of Skilled Forelimb Use Induced by Treatment with Growth Hormone and Rehabilitation Is Dependent on the Onset of the Treatment after Cortical Ablation

Mechanisms of Association of Sleep and Metabolic Syndrome

Healthy Sleep Every Day Keeps the Doctor Away

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