• Korean Journal of Exercise Nutrition
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• v.23 no.3
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• pp.13-21
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• 2019

[Purpose] Chronic stress is a precipitating factor for depression, whereas exercise is beneficial for both the mood and cognitive process. The current study demonstrates the anti-depressive effects of regular exercise and the mechanisms linked to hippocampal neurogenesis. [Methods] Mice were subjected to 14 consecutive days of restraint, followed by 3 weeks of treadmill running, and were then subjected to behavioral tests that included the forced swimming and Y-maze tests. Protein levels were assessed using western blot analysis and newborn cells were detected using 5-bromo-2'-deoxyuridine (BrdU). [Results] Three weeks of treadmill running ameliorated the behavioral depression caused by 14 days of continuous restraint stress. The exercise regimen enhanced BrdU-labeled cells and class III β-tubulin levels in the hippocampal dentate gyrus, as well as those of thioredoxin-1 (TRX-1) and synaptosomal β2-adrenergic receptors (β2-AR) under stress. In vitro experiments involving treatment with recombinant human TRX-1 (rhTRX-1) augmented the levels of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2), nuclear β-catenin, and proliferating cell nuclear antigens, which were previously inhibited by U0216 and FH535 (inhibitors of ERK1/2 and β-catenin/T cell factor-mediated transcription, respectively). The hippocampal neurogenesis elicited by a 7-day exercise regimen was abolished by a selective inhibitor of β2-AR, butoxamine. [Conclusion] These results suggest that TRX-1-mediated hippocampal neurogenesis by β2-AR function is a potential mechanism underlying the psychotropic effect of exercise.

• Toxicological Research
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• v.27 no.2
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• pp.103-110
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• 2011

Lipotoxicity involves pathological alterations to cells and tissues in response to elevated fat levels in blood. Furthermore, this process can disturb both cellular homeostasis and viability. In the current study, the authors show that neural progenitor cells (NPCs) are vulnerable to high levels of palmitic acid (PA) a saturated fatty acid. PA was found to cause cell death associated with elevated reactive oxygen species (ROS) levels, and to reduce NPCs proliferation. To evaluate the lipotoxicity of PA in adult NPCs in the hippocampus, male C57BL/6 mice were divided into two groups and maintained on either a normal diet (ND) or PA-rich high fat diet (HFD) for 2 weeks. Interestingly, short-term PA-rich HFD feeding reduced the survival of newly generated cells in the hippocampal dentate gyrus and hippocampal brain-derived neurotrophic factor levels. These findings suggest PA has a potent lipotoxicity in NPCs and that a PA-rich HFD disrupts hippocampal neurogenesis.

• Genomics & Informatics
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• v.7 no.2
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• pp.85-96
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• 2009

The differentiation of neural precursor cells (NPCs) into neurons and astrocytes is a process that is tightly controlled by complicated and ill-defined gene networks. To extend our knowledge to gene networks, we performed a temporal analysis of gene expression during the differentiation (2, 4, and 8 days) of spinal cord-derived NPCs using oligonucleotide microarray technology. Out of 32,996 genes analyzed, 1878 exhibited significant changes in expression level (fold change>2, p<0.05) at least once throughout the differentiation process. These 1878 genes were classified into 12 groups by k-means clustering, based on their expression patterns. K-means clustering analysis revealed that the genes involved in astrogenesis were categorized into the clusters containing constantly upregulated genes, whereas the genes involved in neurogenesis were grouped to the cluster showing a sudden decrease in gene expression on Day 8. Functional analysis of the differentially expressed genes indicated the enrichment of genes for Pax6- NeuroD signaling.TGFb-SMAD and BMP-SMAD.which suggest the implication of these genes in the differentiation of NPCs and, in particular, key roles for Nova1 and TGFBR1 in the neurogenesis/astrogenesis of mouse spinal cord.

• BMB Reports
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• v.44 no.6
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• pp.421-421
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• 2011

• PNF and Movement
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• v.6 no.2
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• pp.31-38
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• 2008

Purpose: The purpose of this study were to overview the effect of exercise on neural plasticity and the proteins related to neural plasticity. Results: Exercise increased levels of BDNF(brain-derived neurotrophic factor), Insulin-like growth factor-I (IGF-I), Synapsin, Synaptophysin, VEGF(vascular endothelial growth factor) and other growth factors, stimulate neurogenesis, increase resistance to brain insult and improve learning and mental performance. These proteins improved synaptic plasticity by directly affecting synaptic structure and potentiating synaptic strength, and by strengthening the underlying systems that support plasticity including neurogenesis, metabolism and vascular function. Conclusion: Exercise-induced structural and functional change by these proteins can effect on functional movement, cognition in healthy and brain injured people and animals.

• Biomolecules & Therapeutics
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• v.26 no.2
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• pp.93-100
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• 2018

Carbon monoxide (CO) is a gaseous molecule produced from heme by heme oxygenase (HO). Endogenous CO production occurring at low concentrations is thought to have several useful biological roles. In mammals, especially humans, a proper neurovascular unit comprising endothelial cells, pericytes, astrocytes, microglia, and neurons is essential for the homeostasis and survival of the central nervous system (CNS). In addition, the regeneration of neurovascular systems from neural stem cells and endothelial precursor cells after CNS diseases is responsible for functional repair. This review focused on the possible role of CO/HO in the neurovascular unit in terms of neurogenesis, angiogenesis, and synaptic plasticity, ultimately leading to behavioral changes in CNS diseases. CO/HO may also enhance cellular networks among endothelial cells, pericytes, astrocytes, and neural stem cells. This review highlights the therapeutic effects of CO/HO on CNS diseases involved in neurogenesis, synaptic plasticity, and angiogenesis. Moreover, the cellular mechanisms and interactions by which CO/HO are exploited for disease prevention and their therapeutic applications in traumatic brain injury, Alzheimer's disease, and stroke are also discussed.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.5
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• pp.223-229
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• 2006

The emerging concept of the 'neurovascular unit' may enable a powerful paradigm shift for neuroscience. Instead of a pure focus on the 'neurobiology' of disease, an opportunity now exists to return to a more integrative approach. The neurovascular unit emphasizes that signaling between vascular and neuronal compartments comprise the basis for both function and dysfunction in brain. Hence, brain disorders are not just due to death of neurons, but instead manifested as cell signaling perturbations at the neurovascular interface. In this mini-review, we will examine 3 examples of this hypothesis: neurovascular mechanisms involved in the thrombolytic therapy of stroke, the crosstalk between neurogenesis and angiogenesis, and the link between vascular dysfunction and amyloid pathology in Alzheimer's disease. An understanding of cell-cell and cell-matrix signaling at the neurovascular interface may yield new approaches for targeting CNS disorders.

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2002.08a
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• pp.11-11
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• 2002

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.3-19
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• 2001

Recent basic and clinical studies demonstrate a major role for neural plasticity in the etiology and treatment of depression and stress-related illness. The neural plasticity is reflected both in the birth of new cell in the adult brain(neurogenesis) and the death of genetically healthy cells(apoptosis) in the response to the individual's interaction with the environment. The neural plasticity includes adaptations of intracellular signal transduction pathway and gene expression, as well as alterations in neuronal morphology and cell survival. At the cellular level, repeated stress causes shortening and debranching of dendrite in the CA3 region of hippocampus and suppress neurogenesis of dentate gyrus granule neurons. At the molecular level, both form of structural remodeling appear to be mediated by glucocorticoid hormone working in concert with glutamate and N-methyl-D-aspartate(NMDA) receptor, along with transmitters such as serotonin and GABA-benzodiazepine system. In addition, the decreased expression and reduced level of brain-derived neurotrophic factor(BDNF) could contribute the atrophy and decreased function of stress-vulnerable hippocampal neurons. It is also suggested that atrophy and death of neurons in the hippocampus, as well as prefrontal cortex and possibly other regions, could contribute to the pathophysiology of depression. Antidepressant treatment could oppose these adverse cellular effects, which may be regarded as a loss of neural plasticity, by blocking or reversing the atrophy of hippocampal neurons and by increasing cell survival and function via up-regulation of cyclic adenosine monophosphate response element-binding proteins(CREB) and BDNF. In this article, the molecular and cellular mechanisms that underlie stress, depression, and action of antidepressant are precisely discussed.

• Biomolecules & Therapeutics
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• v.28 no.3
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• pp.282-291
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• 2020

Inhaled solvents such as toluene are of particular concern due to their abuse potential that is easily exposed to the environment. The inhalation of toluene causes various behavioral problems, but, the effect of short-term exposure of toluene on changes in emotional behaviors over time after exposure and the accompanying pathological characteristics have not been fully identified. Here, we evaluated the behavioral and neurochemical changes observed over time in mice that inhaled toluene. The mice were exposed to toluene for 30 min at a concentration of either 500 or 2,000 ppm. Toluene did not cause social or motor dysfunction in mice. However, increased anxiety-like behavior was detected in the short-term after exposure, and depression-like behavior appeared as delayed effects. The amount of striatal dopamine metabolites was significantly decreased by toluene, which continued to be seen for up to almost two weeks after inhalation. Additionally, an upregulation of serotonin 1A (5-HT_1A) receptor in the hippocampus and the substantia nigra, as well as reduced immunoreactivity of neurogenesis markers in the dentate gyrus, was observed in the mice after two weeks. These results suggest that toluene inhalation, even single exposure, mimics early anxiety-and delayed depression-like emotional disturbances, underpinned by pathological changes in the brain.