scholarly journals Depression, Brain Glucose Metabolism and Consciousness

Author(s):  
Maria Alice Ornellas Pereira ◽  
Alfredo Pereira Jr ◽  
Gene Johnson

A correlation between depression and resistance to insulin was recently discovered. How to conciliate this finding with the fact that glucose transport to neurons is not made directly by insulin? We present an explanatory hypothesis based on a mechanism of dynamical glucose balance in the brain that includes lactate transport from astrocytes to neuronal mitochondria supporting ATP (and then cAMP) production. The depressed brain has defective ATP production, possibly leading in several cases to excessive glucose consumption without increasing neuronal ATP levels. This hypothesis can help to explain the surprisingly positive results found in the treatment of depression with aromatherapy. Some odors like citrus fragrances possibly fool the brain’s glucose level sensors, reducing the subjective feeling of "low energy". Could a conscious process trigger a reaction against the underlying causes of depression?

1983 ◽  
Vol 3 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Hideo Mabe ◽  
Photjanee Blomqvist ◽  
Bo K. Siesjö

The objective of the present study was to discover whether or not intracellular alkalosis develops in the brain in the recovery period following transient ischemia. Forebrain ischemia of 15-min duration was induced by four-vessel occlusion in rats, with recovery periods of 15, 60, and 180 min. Intracellular pH was derived both by the HCO3−–H2CO3 method and from the creatine kinase equilibrium. The ischemia was associated with energy failure and marked accumulation of lactic acid in the cerebral cortex. Recirculation brought about rapid rephosphorylation of adenine nucleotides and gradual normalization of lactic acid levels. After 15 min of recovery, the HCO3−–H2CO3 method indicated persisting acidosis, but the creatine kinase reaction did not. After 60 min, a shift of pH in the alkaline direction was demonstrated in both methods. This alkalosis had disappeared after 3 h of recovery. It is concluded that resumption of ATP production after ischemia is followed by a rapid rise in intracellular pH, which transiently increases above normal.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Jonathan Singer ◽  
Alyssa Conigliaro ◽  
Elizabeth Spina ◽  
Susan Law ◽  
Steven Levine

Background: Central Post Stroke Pain (CPSP) is reportedly due to strokes in the thalamic region (Dishinbition Theory); however, the Central Imbalance Theory states that CPSP is due to damage to the spinothalamic pathway (STP). Aims: 1) Clarify the role of thalamic strokes and STP damage in CPSP patients. 2) Gain a current understanding of anatomic substrates, brain imaging, and treatment of CPSP. Methods: Two independent reviewers systematically reviewed PUBMED, CINAHL and Web of Science for studies including original, clinical studies and randomized controlled trials (RCTs) using PRISMA guidelines. Studies had to assess CPSP, using a single question or pain scale. Results: Search from January – July 2016, identifying 731 publications. We extracted data from 23 studies and categorized the articles’ aims into 4 sections: somatosensory deficits (5 studies), STP (3 studies), brain imaging (7 studies), and RCTs (8 studies). Somatosensory studies showed high rates of CPSP; however, the underlying causes of these deficits were unclear. Most studies did not refer to stroke location as playing a role in CPSP, but that pathways may. STP studies displayed consistent evidence that the STP plays a major role in CPSP, delineating that CPSP can occur even when the stroke is not in the thalamic region but in other regions (e.g. cerebellum, basal ganglia, medulla). Four of the brain imaging studies found CPSP not related and 3 found it was related to thalamic strokes. All 7 studies had major limitations including sample size, no control groups, and selection bias. RCTs were mostly negative, but brain stem and motor cortex stimulation studies showed the most promise. Conclusions: While CPSP has been linked to the thalamic region since the early 1900’s, the peer-reviewed literature showed equivocal results when examining location of stroke. Our systematic review suggests damage to the STP is associated with CPSP and this could provide insights into mechanisms and treatment. Moreover, historical connection of strokes in the thalamic region and CPSP should be reevaluated as many studies noted that strokes in other regions of the brain also produce CPSP.


1994 ◽  
Vol 267 (2) ◽  
pp. R590-R595 ◽  
Author(s):  
G. E. Nilsson ◽  
P. Hylland ◽  
C. O. Lofman

The crucian carp (Carassius carassius) has the rare ability to survive prolonged anoxia, indicating an extraordinary capacity for glycolytic ATP production, especially in a highly energy-consuming organ like the brain. For the brain to be able to increase its glycolytic flux during anoxia and profit from the large liver glycogen store, an increased glucose delivery from the blood would be expected. Nevertheless, the effect of anoxia on brain blood flow in crucian carp has never been studied previously. We have used epireflection microscopy to directly observe and measure blood flow rate on the brain surface (optic lobes) during normoxia and anoxia in crucian carp. We have also examined the possibility that adenosine participates in the regulation of brain blood flow rate in crucian carp. The results showed a 2.16-fold increase in brain blood flow rate during anoxia. A similar increase was seen after topical application of adenosine during normoxia, while adenosine was without effect during anoxia. Moreover, superfusing the brain with the adenosine receptor blocker aminophylline inhibited the effect of anoxia on brain blood flow rate, clearly suggesting a mediatory role of adenosine in the anoxia-induced increase in brain blood flow rate.


2022 ◽  
pp. 95-104
Author(s):  
E. Yu. Plotnikova ◽  
M. N. Sinkova ◽  
L. K. Isakov

Asthenia and fatigue are the most common syndromes in patients with liver disease, which significantly affects their quality of life. The prevalence of fatigue in chronic liver diseases is from 50% to 85%. While some progress has been made in understanding the processes that can cause fatigue in general, the underlying causes of fatigue associated with liver disease remain not well understood. In particular, many data suggest that fatigue associated with liver disease likely results from changes in neurotransmission in the brain against the background of hyperammonemia. Hyperammonemia is a metabolic state characterized by an increased level of  ammonia, a  nitrogen-containing compound. The  present review describes hyperammonemia, which is likely important in the pathogenesis of fatigue associated with liver disease. Ammonia is a potent neurotoxin, its elevated blood levels can cause neurological signs and symptoms that can be acute or chronic, depending on the  underlying pathology. Hyperammonemia should be recognized early, and immediately treated to prevent the development of life-threatening complications, such as, swelling of the brain and coma. The article gives pathophysiological mechanisms of influence of hyperammonemia on state of psychovegetative status of patients with liver diseases, also lists basic principles of treatment. A significant part of the article is devoted to L-ornithine-L-aspartate, which is effective in asthenia and fatigue to reduce the level of hyperammonemia through a variety of well-studied mechanisms in chronic liver diseases.


2021 ◽  
Vol 16 ◽  
Author(s):  
Praful Giradkar ◽  
Deepa H. Patel

Introduction: The aim of present research work was to prepare, optimized, and evaluate the multi-dose nasal spray solution for delivery of vilazodone hydrochloride to the brain by the intranasal route in order to overcome the drawback associated with the oral route for the treatment of depression. Background: Depression is a mental disorder associated with abnormalities in neuronal transport in the brain primarily serotonin, norepinephrine, and dopamine that adversely affects a person's lifestyle, sleep pattern, work, eating habits, and general health. Vilazodone hydrochloride acts by enhancing the serotonergic activity in the brain by inhibiting serotonin (5-HT) reuptake. Materials/ Methods: The excipients used to formulate vilazodone hydrochloride multi-dose nasal spray solution were sulphobutylether-β-cyclodextrin sodium (solubilizer), sodium carboxymethylcellulose (viscosity builder), tween 80 (surface tension modifier), glycerol (humectant), benzalkonium chloride (preservative), and purified water (vehicle). The simple conventional mixing technique was used for the preparation of the multi-dose nasal spray solution. The solution was prepared in two parts, in the first part sulphobutylether-β-cyclodextrin sodium and drug substance dissolved in purified water under stirring followed by the addition of glycerol and benzalkonium chloride solution. In the second part, tween 80 dissolved in warm water followed by the addition of sodium carboxymethylcellulose under stirring, finally both parts mixed and the required volume was adjusted with purified water. The central composite design was used for the optimization of the formulation. The solution was evaluated for physicochemical properties, selective toxicity, and experimental kinetics. Results: The prepared vilazodone hydrochloride multi-dose nasal spray solution was shown viscosity (40.5 ± 1.65 mPa.s), droplet size distribution (span) (1.88 ± 0.55 µm), spray area (288 ± 1.25 mm2), ovality (1.10 ± 1.35), dripping speed (0.25 cm /30 sec), visual appearance (clear free from particulate matter), pH (6.35 ± 0.10), shot weight (100.6 ± 0.32 mg), density (1.03 ± 0.20 g/ml), % drug content (101.8 ± 0.15 %), displacement value for in-vitro mucoadhesion (3.47 ± 0.25 cm), average flux (Jss) for permeability (241.06 ± 1.45 μg/cm2/hrs), permeability coefficient (48.21 ±1.46 cm/hrs), enhancement ratio (1.73), local toxicity study shows no epithelium cell damage, isotonicity (386.58 mOsmol / kg). Plasma Cmax (24.56 ±3.98 ng/ml), Tmax (1.0 hrs), and AUC 0-12 (82.68 ±10.22 ng.h/ml). Brian tissue Cmax (22.95 ±4.22), Tmax (1.0 hrs) and AUC 0-12 (77.82 ±6.25 ng.h/ml). Nasal bioavailability (251.74 ±45.12% ) and, drug targeting index 1.54 Conclusion: The present research work results showed that the prepared multi-dose nasal spray solution of vilazodone hydrochloride was suitable for the delivery of the drug to the brain by the intranasal route and might be beneficial to overcome drawbacks associated with the oral route of administration for the treatment of depression.


Author(s):  
Daniel W. O’Connor ◽  
Christos Plakiotis ◽  
Peter Farnbach

Electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) all entail the delivery of electrical impulses to the brain with the aim of relieving mental disorders. ECT is an effective treatment of depression, mania and catatonia and, to a lesser extent, of schizophrenia. Its side effects, principally cognitive impairment, are mitigated through the use of individually tailored, unilateral delivery. TMS is more convenient but of lesser effectiveness. DBS, while reversible and thus safer than lesional surgery, is a major undertaking that is reserved at present for profoundly disabling depression, obsessive-compulsive disorder (OCD), and Tourette’s syndrome.


2019 ◽  
Vol 20 (4) ◽  
pp. 941 ◽  
Author(s):  
Mitsuhiro Morita ◽  
Hiroko Ikeshima-Kataoka ◽  
Marko Kreft ◽  
Nina Vardjan ◽  
Robert Zorec ◽  
...  

As part of the blood-brain-barrier, astrocytes are ideally positioned between cerebral vasculature and neuronal synapses to mediate nutrient uptake from the systemic circulation. In addition, astrocytes have a robust enzymatic capacity of glycolysis, glycogenesis and lipid metabolism, managing nutrient support in the brain parenchyma for neuronal consumption. Here, we review the plasticity of astrocyte energy metabolism under physiologic and pathologic conditions, highlighting age-dependent brain dysfunctions. In astrocytes, glycolysis and glycogenesis are regulated by noradrenaline and insulin, respectively, while mitochondrial ATP production and fatty acid oxidation are influenced by the thyroid hormone. These regulations are essential for maintaining normal brain activities, and impairments of these processes may lead to neurodegeneration and cognitive decline. Metabolic plasticity is also associated with (re)activation of astrocytes, a process associated with pathologic events. It is likely that the recently described neurodegenerative and neuroprotective subpopulations of reactive astrocytes metabolize distinct energy substrates, and that this preference is supposed to explain some of their impacts on pathologic processes. Importantly, physiologic and pathologic properties of astrocytic metabolic plasticity bear translational potential in defining new potential diagnostic biomarkers and novel therapeutic targets to mitigate neurodegeneration and age-related brain dysfunctions.


2020 ◽  
Vol 21 (18) ◽  
pp. 6739
Author(s):  
Sharmeelavathi Krishnan ◽  
Yasaswi Shrestha ◽  
Dona P. W. Jayatunga ◽  
Sarah Rea ◽  
Ralph Martins ◽  
...  

Neurodegenerative diseases result in a range of conditions depending on the type of proteinopathy, genes affected or the location of the degeneration in the brain. Proteinopathies such as senile plaques and neurofibrillary tangles in the brain are prominent features of Alzheimer’s disease (AD). Autophagy is a highly regulated mechanism of eliminating dysfunctional organelles and proteins, and plays an important role in removing these pathogenic intracellular protein aggregates, not only in AD, but also in other neurodegenerative diseases. Activating autophagy is gaining interest as a potential therapeutic strategy for chronic diseases featuring protein aggregation and misfolding, including AD. Although autophagy activation is a promising intervention, over-activation of autophagy in neurodegenerative diseases that display impaired lysosomal clearance may accelerate pathology, suggesting that the success of any autophagy-based intervention is dependent on lysosomal clearance being functional. Additionally, the effects of autophagy activation may vary significantly depending on the physiological state of the cell, especially during proteotoxic stress and ageing. Growing evidence seems to favour a strategy of enhancing the efficacy of autophagy by preventing or reversing the impairments of the specific processes that are disrupted. Therefore, it is essential to understand the underlying causes of the autophagy defect in different neurodegenerative diseases to explore possible therapeutic approaches. This review will focus on the role of autophagy during stress and ageing, consequences that are linked to its activation and caveats in modulating this pathway as a treatment.


Author(s):  
APOORVA HA ◽  
SEEMA MEHDI ◽  
KRISHNA KL ◽  
NABEEL K

Depression is a condition of no mood and loss of interest in any activity that can diminish a person’s thinking, conduct, tendencies, emotional state, and a sense of well-being. Although there is a conventional class of medication which have been beneficial in the treatment of depression, current studies have reported having side effects which can be minimized by the intervention of herbs and phytochemicals. Most of the studies have proven the various mechanisms and have started to research a very ground-breaking method by glancing the ancient treatmen. Where this new approach of using the herbs and phytochemicals has shown better results alone and in combination with conventional drugs which has shown lesser adverse effects. The practice of phytomedicine is an additional option for the treatment of depression. In the various segments of treating the depression, the mainstream can be a breakthrough including phytoconstituents. In this aspect, there are many contributions for the treatment of the depression acting to the neuronal level signaling and the phytoconstituents also have shown some basic mechanisms in the treatment of depression as that of the conventional medications following some primary hypothesis and signaling pathways and life interactions that effects the brain in either way to treat the depression in all sort of way. Clinical evidence is required to provide backing to the safety and effectiveness of herbs and phytochemicals alone or in combination with currently available drugs to overcome the reported side effects during the treatment of depression.


NeuroImage ◽  
2016 ◽  
Vol 128 ◽  
pp. 54-62 ◽  
Author(s):  
Heiko Backes ◽  
Maureen Walberer ◽  
Anne Ladwig ◽  
Maria A. Rueger ◽  
Bernd Neumaier ◽  
...  

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