scholarly journals Energy Metabolism Decline in the Aging Brain—Pathogenesis of Neurodegenerative Disorders

Metabolites ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 450
Author(s):  
Janusz Wiesław Błaszczyk
Keyword(s):  
Energy Metabolism ◽  
Neurodegenerative Disorders ◽  
Clinical Symptoms ◽  
Neuronal Degeneration ◽  
Brain Structures ◽  
Aging Brain ◽  
Atp Production ◽  
Sequence Of Events ◽  
Age Related ◽  
The Brain

There is a growing body of evidencethat indicates that the aging of the brain results from the decline of energy metabolism. In particular, the neuronal metabolism of glucose declines steadily, resulting in a growing deficit of adenosine triphosphate (ATP) production—which, in turn, limits glucose access. This vicious circle of energy metabolism at the cellular level is evoked by a rising deficiency of nicotinamide adenine dinucleotide (NAD) in the mitochondrial salvage pathway and subsequent impairment of the Krebs cycle. A decreasing NAD level also impoverishes the activity of NAD-dependent enzymes that augments genetic errors and initiate processes of neuronal degeneration and death.This sequence of events is characteristic of several brain structures in which neurons have the highest energy metabolism. Neurons of the cerebral cortex and basal ganglia with long unmyelinated axons and these with numerous synaptic junctions are particularly prone to senescence and neurodegeneration. Unfortunately, functional deficits of neurodegeneration are initially well-compensated, therefore, clinical symptoms are recognized too late when the damages to the brain structures are already irreversible. Therefore, future treatment strategies in neurodegenerative disorders should focus on energy metabolism and compensation age-related NAD deficit in neurons. This review summarizes the complex interrelationships between metabolic processes on the systemic and cellular levels and provides directions on how to reduce the risk of neurodegeneration and protect the elderly against neurodegenerative diseases.

scholarly journals Energy Metabolism Decline in the Aging Brain; Pathogenesis of Neurodegenerative Disorders

2020 ◽  
Author(s):  
Janusz Błaszczyk
Keyword(s):  
Energy Metabolism ◽  
Neurodegenerative Diseases ◽  
Krebs Cycle ◽  
Brain Structures ◽  
The Elderly ◽  
Review Article ◽  
Aging Brain ◽  
Salvage Pathway ◽  
Atp Production ◽  
The Brain

A growing body of evidence indicates that aging of the brain is strictly related to the decline of energy metabolism. In particular, in older adults, the neuronal metabolism of glucose declines steadily resulting in a growing deficit of ATP production. The decline is evoked by deficient NAD recovery in the salvage pathway and subsequent impairment of the Krebs cycle. NAD deficit impairs also the activity of NAD-dependent enzymes. All these open vicious circles of neurodegeneration and neuronal death. Some brain structures are particularly prone to aging and neurodegeneration. These are pathological foci of neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. This review article summarizes the impacts and mutual relationships between metabolic processes both on neuronal and brain levels. It also provides directions on how to reduce the risk of neurodegeneration and protect the elderly against neurodegenerative diseases.

scholarly journals The aging mind: neuroplasticity in response to cognitive training

2013 ◽  
Vol 15 (1) ◽  
pp. 109-119 ◽  
Keyword(s):  
Cognitive Function ◽  
Cognitive Training ◽  
Neural Plasticity ◽  
Cognitive Effort ◽  
Aging Brain ◽  
Cognitive Domains ◽  
Training Techniques ◽  
Age Related ◽  
Strategy Change ◽  
The Brain

Is it possible to enhance neural and cognitive function with cognitive training techniques? Can we delay age-related decline in cognitive function with interventions and stave off Alzheimer's disease? Does an aged brain really have the capacity to change in response to stimulation? In the present paper, we consider the neuroplasticity of the aging brain, that is, the brain's ability to increase capacity in response to sustained experience. We argue that, although there is some neural deterioration that occurs with age, the brain has the capacity to increase neural activity and develop neural scaffolding to regulate cognitive function. We suggest that increase in neural volume in response to cognitive training or experience is a clear indicator of change, but that changes in activation in response to cognitive training may be evidence of strategy change rather than indicative of neural plasticity. We note that the effect of cognitive training is surprisingly durable over time, but that the evidence that training effects transfer to other cognitive domains is relatively limited. We review evidence which suggests that engagement in an environment that requires sustained cognitive effort may facilitate cognitive function.

scholarly journals Metabolic Plasticity of Astrocytes and Aging of the Brain

2019 ◽  
Vol 20 (4) ◽  
pp. 941 ◽  
Author(s):  
Mitsuhiro Morita ◽  
Hiroko Ikeshima-Kataoka ◽  
Marko Kreft ◽  
Nina Vardjan ◽  
Robert Zorec ◽  
...  
Keyword(s):  
Systemic Circulation ◽  
Brain Parenchyma ◽  
Acid Oxidation ◽  
Normal Brain ◽  
Atp Production ◽  
Metabolic Plasticity ◽  
Neuronal Synapses ◽  
Age Related ◽  
Pathologic Processes ◽  
The Brain

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.

scholarly journals Cerebral malaria: why experimental murine models are required to understand the pathogenesis of disease

Parasitology ◽  
2009 ◽  
Vol 137 (5) ◽  
pp. 755-772 ◽  
Author(s):  
J. BRIAN de SOUZA ◽  
JULIUS C. R. HAFALLA ◽  
ELEANOR M. RILEY ◽  
KEVIN N. COUPER
Keyword(s):  
Cerebral Malaria ◽  
Malaria Infection ◽  
Clinical Symptoms ◽  
Experimental Models ◽  
Murine Models ◽  
Experimental Cerebral Malaria ◽  
Sequence Of Events ◽  
Life Threatening ◽  
Life Threatening Complication ◽  
The Brain

SUMMARYCerebral malaria is a life-threatening complication of malaria infection. The pathogenesis of cerebral malaria is poorly defined and progress in understanding the condition is severely hampered by the inability to study in detail,ante-mortem, the parasitological and immunological events within the brain that lead to the onset of clinical symptoms. Experimental murine models have been used to investigate the sequence of events that lead to cerebral malaria, but there is significant debate on the merits of these models and whether their study is relevant to human disease. Here we review the current understanding of the parasitological and immunological events leading to human and experimental cerebral malaria, and explain why we believe that studies with experimental models of CM are crucial to define the pathogenesis of the condition.

Age-related changes in microglial physiology: the role for healthy brain ageing and neurodegenerative disorders

e-Neuroforum ◽  
2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Olga Garaschuk
Keyword(s):  
Neurodegenerative Disorders ◽  
Healthy Aging ◽  
Molecular Mechanisms ◽  
Brain Parenchyma ◽  
Immune Defense ◽  
Synaptic Activity ◽  
Mammalian Brain ◽  
Age Related ◽  
Brain Ageing ◽  
The Brain

AbstractMicroglia are the main immune cells of the brain contributing, however, not only to brain’s immune defense but also to many basic housekeeping functions such as development and maintenance of functional neural networks, provision of trophic support for surrounding neurons, monitoring and modulating the levels of synaptic activity, cleaning of accumulating extracellular debris and repairing microdamages of the brain parenchyma. As a consequence, age-related alterations in microglial function likely have a manifold impact on brain’s physiology. In this review, I discuss the recent data about physiological properties of microglia in the adult mammalian brain; changes observed in the brain innate immune system during healthy aging and the probable biological mechanisms responsible for them as well as changes occurring in humans and mice during age-related neurodegenerative disorders along with underlying cellular/molecular mechanisms. Together these data provide a new conceptual framework for thinking about the role of microglia in the context of age-mediated brain dysfunction.

scholarly journals The Contribution ofα-Synuclein Spreading to Parkinson’s Disease Synaptopathy

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Francesca Longhena ◽  
Gaia Faustini ◽  
Cristina Missale ◽  
Marina Pizzi ◽  
PierFranco Spano ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Disorders ◽  
Physiological Conditions ◽  
Age Related ◽  
Endogenous Protein ◽  
Synaptic Failure ◽  
Nigrostriatal Neurons ◽  
Somatic Nervous System ◽  
The Brain

Synaptopathies are diseases with synapse defects as shared pathogenic features, encompassing neurodegenerative disorders such as Parkinson’s disease (PD). In sporadic PD, the most common age-related neurodegenerative movement disorder, nigrostriatal dopaminergic deficits are responsible for the onset of motor symptoms that have been related toα-synuclein deposition at synaptic sites. Indeed,α-synuclein accumulation can impair synaptic dopamine release and induces the death of nigrostriatal neurons. While in physiological conditions the protein can interact with and modulate synaptic vesicle proteins and membranes, numerous experimental evidences have confirmed that its pathological aggregation can compromise correct neuronal functioning. In addition, recent findings indicate thatα-synuclein pathology spreads into the brain and can affect the peripheral autonomic and somatic nervous system. Indeed, monomeric, oligomeric, and fibrillaryα-synuclein can move from cell to cell and can trigger the aggregation of the endogenous protein in recipient neurons. This novel “prion-like” behavior could further contribute to synaptic failure in PD and other synucleinopathies. This review describes the major findings supporting the occurrence ofα-synuclein pathology propagation in PD and discusses how this phenomenon could induce or contribute to synaptic injury and degeneration.

scholarly journals Impaired Mitophagy in Neurons and Glial Cells during Aging and Age-Related Disorders

2021 ◽  
Vol 22 (19) ◽  
pp. 10251
Author(s):  
Vladimir Sukhorukov ◽  
Dmitry Voronkov ◽  
Tatiana Baranich ◽  
Natalia Mudzhiri ◽  
Alina Magnaeva ◽  
...  
Keyword(s):  
Glial Cells ◽  
Brain Aging ◽  
Cellular Level ◽  
Aging Brain ◽  
The Past ◽  
Age Related ◽  
Accumulation Of Damage ◽  
Quantity Control ◽  
The Brain

Aging is associated with a decline in cognitive function, which can partly be explained by the accumulation of damage to the brain cells over time. Neurons and glia undergo morphological and ultrastructure changes during aging. Over the past several years, it has become evident that at the cellular level, various hallmarks of an aging brain are closely related to mitophagy. The importance of mitochondria quality and quantity control through mitophagy is highlighted by the contribution that defects in mitochondria–autophagy crosstalk make to aging and age-related diseases. In this review, we analyze some of the more recent findings regarding the study of brain aging and neurodegeneration in the context of mitophagy. We discuss the data on the dynamics of selective autophagy in neurons and glial cells during aging and in the course of neurodegeneration, focusing on three mechanisms of mitophagy: non-receptor-mediated mitophagy, receptor-mediated mitophagy, and transcellular mitophagy. We review the role of mitophagy in neuronal/glial homeostasis and in the molecular pathogenesis of neurodegenerative disorders, such as Parkinson’s disease, Alzheimer’s disease, and other disorders. Common mechanisms of aging and neurodegeneration that are related to different mitophagy pathways provide a number of promising targets for potential therapeutic agents.

scholarly journals Chronic administration of a positive allosteric modulator at the α5-GABAA receptor reverses age-related dendritic shrinkage

2020 ◽  
Author(s):  
Thomas D. Prevot ◽  
Akiko Sumitomo ◽  
Toshifumi Tomoda ◽  
Daniel E. Knutson ◽  
Guanguan Li ◽  
...  
Keyword(s):  
Life Expectancy ◽  
Cognitive Decline ◽  
Neuronal Morphology ◽  
Aging Brain ◽  
Primary Neuronal Culture ◽  
Efficient Treatment ◽  
Gaba A ◽  
Age Related ◽  
Β Amyloid ◽  
The Brain

ABSTRACTOver the last 15 years, worldwide life expectancy increased by 5 years jumping from 66 years to 71 years. With progress in science, medicine, and care we tend to live longer. Such extended life expectancy is still associated with age-related changes, including in the brain. The aging brain goes through various changes that can be called morphomolecular senescence. Overall, the brain volume changes, neuronal activity is modified and plasticity of the cells diminishes, sometimes leading to neuronal atrophy and death. Altogether, these changes contribute to the emergence of cognitive decline that still does not have an efficient treatment available. Many studies in the context of cognitive decline focused on pathological aging, targeting β-amyloid in Alzheimer’s disease, for example. However, β-amyloid plaques are also present in healthy adults and treatments targeting plaques have failed to improve cognitive functions. In order to improve the quality of life of aging population, it is crucial to focus on the development of novel therapies targeting different systems altered during aging, such as the GABAergic system. In previous studies, it has been shown that positive allosteric modulators (PAM) acting at the α5-containing GABA-A receptors improve cognitive performances, and that these α5-GABA-A receptors are implicated in dendritic growth of pyramidal neurons. Here, we hypothesized that targeting the α5-GABA-A receptors could contribute to the reduction of cognitive decline, directly through activity of the receptors, and indirectly by increasing neuronal morphology. Using primary neuronal culture and chronic treatment in mice, we demonstrated that an α5-PAM increased dendritic length, spine count and spine density in brain regions involved in cognitive processes (prefrontal cortex and hippocampus). We also confirmed the procognitive efficacy of the α5-PAM and showed that the washout period diminishes the precognitive effects without altering the effect on neuronal morphology. Future studies will be needed to investigate what downstream mechanisms responsible for the neurotrophic effect of the α5-PAM.

scholarly journals Neuroprotective Potential of GDF11: Myth or Reality?

2019 ◽  
Vol 20 (14) ◽  
pp. 3563 ◽  
Author(s):  
Luc Rochette ◽  
Gabriel Malka
Keyword(s):  
Neurodegenerative Diseases ◽  
Blood Plasma ◽  
Neurodegenerative Disorders ◽  
Brain Aging ◽  
Therapeutic Strategies ◽  
Blood Concentrations ◽  
Age Related ◽  
Novel Therapeutic Strategies ◽  
The Brain ◽  
Novel Therapeutic

In the brain, aging is accompanied by cellular and functional deficiencies that promote vulnerability to neurodegenerative disorders. In blood plasma from young and old animals, various factors such as growth differentiation factor 11 (GDF11), whose levels are elevated in young animals, have been identified. The blood concentrations of these factors appear to be inversely correlated with the age-related decline of neurogenesis. The identification of GDF11 as a “rejuvenating factor” opens up perspectives for the treatment of neurodegenerative diseases. As a pro-neurogenic and pro-angiogenic agent, GDF11 may constitute a basis for novel therapeutic strategies.

N-acetyl-l-cysteine attenuates oxidative damage and neurodegeneration in rat brain during aging

2018 ◽  
Vol 96 (12) ◽  
pp. 1189-1196 ◽  
Author(s):  
Geetika Garg ◽  
Sandeep Singh ◽  
Abhishek Kumar Singh ◽  
Syed Ibrahim Rizvi
Keyword(s):  
Rat Brain ◽  
Neuroprotective Effect ◽  
Neuron Specific Enolase ◽  
Sirtuin 1 ◽  
Marker Genes ◽  
Aging Brain ◽  
Age Related ◽  
Nonenzymatic Antioxidants ◽  
Old Rats ◽  
The Brain

N-acetyl-l-cysteine (NAC) is a precursor of cysteine, which is known to increase the level of glutathione (GSH) in the brain. Several neurodegenerative changes linked to oxidative stress take place in the aging brain. This study aimed to assess the neuroprotective effect of NAC supplementation on age-dependent neurodegeneration in the rat brain. Young (4 months) and old (24 months) Wistar rats (n = 6 rats/group) were supplemented with NAC (100 mg/kg b.w. orally) for 14 days. Enzymatic and nonenzymatic antioxidants such as superoxide dismutase and catalase, and GSH and total thiol respectively, prooxidants such as protein carbonyl, advanced oxidation protein products, reactive oxygen species, and malondialdehyde were assessed in the brain homogenates. Furthermore, nitric oxide level, acetylcholinesterase activity, and Na+/K+–ATPase activity were measured and gene expression studies were also performed. The results indicated that NAC augmented the level of enzymatic and nonenzymatic antioxidants with a significant reduction in prooxidant levels in old rats. NAC supplementation also downregulated the expression of inflammatory markers (TNF-α, IL-1β, IL-6) and upregulated the expression of marker genes associated with aging (sirtuin-1) and neurodegeneration (neuron-specific enolase, neuroglobin, synapsin-I, myelin basic protein 2) in old rats. The present findings support a neuroprotective role of NAC which has therapeutic implication in controlling age-related neurological disorders.

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