•Engaging in physical activity can reduce depressive symptoms.•Exercise stimulates several neuroplastic processes implicated in depression.•It also reduces inflammation and increases resilience to ...oxidative and physiological stress.•Exercise promotes self-esteem, social support and self-efficacy.•Understanding these mechanisms can improve the design of exercise interventions and maximise treatment response.
Physical activity can treat and prevent depressive symptoms, but its antidepressant mechanisms are yet to be established. In this review, we comprehensively assess key biological and psychosocial mechanisms through which physical activity exerts antidepressant effects, with a particular focus on exercise.
Exercise, a subset of physical activity, influences a range of biological and psychosocial processes also implicated in the pathophysiology of depression. We focus on the capacity for exercise to elicit changes in neuroplasticity, inflammation, oxidative stress, the endocrine system, self-esteem, social support and self-efficacy. We also discuss how a better understanding of these mechanisms can inform the way we design and implement exercise-based interventions to maximise their antidepressant effects on an individual basis. We conclude by presenting a conceptual framework of the key biological and psychosocial mechanisms underlying the relationship between physical activity and depressive symptoms, and the moderators and confounders that may influence it.
Introduction: Mentally Guided Imagery (MGI) has successfully been applied in sports for skill acquisition and performance enhancement. Despite the fact that athletes often use mental imagery as a ...part of their preparation, it has not been extensively explored as a learning technique in medical education. Few studies had highlighted mental imagery as a way to review and practice surgical skills efficiently. The present study aimed to assess the efficiency of intubation skills acquired through mental imagery in medical interns. Aim: To assess and compare the effect of Guided mental imagery and physical practice using mannequins on intubation technique among 40 medical Interns after seven days of training. Materials and Methods: The study was conducted in the Department of Emergency Medicine, Velammal Medical College and Hospital, Madurai over a period of seven days. Forty house surgeons were randomly divided into two groups. Group A (n=20) practiced MGI on intubation technique and Group B (n=20) practiced on mannequins one hour everyday for seven days. The performance of the students was assessed using a graded Objective Structured Clinical Examination (OSCE). Results: Results of Group A and Group B were analysed and compared statistically using paired and unpaired t-test. Though there was significant difference between the pre and post values in the MGI group (p<0.001), there was no statistically significant difference (p=0.216) in the post-intervention scores between the Mentally Guided Imagery (MGI) and physical practice group. Conclusion: Guided mental imagery was as effective as additional physical practice for medical students learning to perform intubation.
Depression represents a global mental health concern, and disproportionally affects women as they are twice more likely to be diagnosed than men. In this review, we provide a summary of evidence to ...support the notion that differences in depression between men and women span multiple facets of the disease, including epidemiology, symptomology, treatment, and pathophysiology. Through a lens of biological sex, we overview depression-related transcriptional patterns, changes in neuroanatomy and neuroplasticity, and immune signatures. We acknowledge the unique physiological and behavioral demands of pregnancy and motherhood by devoting special attention to depression occurring in the peripartum period. Specifically, we discuss issues surrounding the presentation, time course, treatment, and neurobiology of peripartum depression. We write this review with the intention of highlighting the encouraging advancements in our understanding of sex differences in depression, while underscoring the gaps that remain. A more systematic consideration of biological sex as a variable in depression research will be critical in the discovery and development of pharmacotherapies that are efficacious for both men and women.
•Physical activity is identified as a promising therapeutic method for depression•Explore what kind of exercise is more suitable for elderly patients with depression•Focus on the dose-response ...relationship between physical activity and depression•Physical activity compared with antidepressant medication•Potential mechanisms linking physical activity with depression
This study provides a comprehensive and updated review of the literature with respect to the relationship between physical activity and depression in older adults. The evidence from both observational studies and experimental studies are collected to present a discussion on the type and dose of physical activity, as well as the underlying mechanisms of physical activity and depression in older adults. Overall, the results from previous studies support a solid inverse relationship between physical activity and depression in older adults, while the dose-effect relationship between them, as well as different effects among different types of physical activities, remains largely unexplored. Depression in older adults is related to an array of negative health outcomes and is more chronic compared to that in younger adults. Physical activity has been regarded as a promising non-pharmaceutical method in treating and preventing depression in older adults. Further experimental work and research need to be done to develop theoretically grounded and evidence-based interventions to better advance our knowledge of this topic and effectively promote physical activity in older adults.
Endogenous cannabinoids (eCB) mediate synaptic plasticity in brain regions involved in learning and reward. Here we show that in mice, a single in-vivo exposure to Δ9-tetrahydrocannabinol (THC) ...abolishes the retrograde signaling that underlies eCB-mediated synaptic plasticity in both nucleus accumbens (NAc) and hippocampus in vitro. This effect is reversible within 3 days and is associated with a transient modification in the functional properties of cannabinoid receptors.
•Hypoxic-ischemic encephalopathy is the leading cause of neonatal encephalopathy.•Therapeutic hypothermia offers limited improvement in neurodevelopmental outcomes.•Transcranial ultrasound ...stimulation (TUS) can modulate specific brain regions.•TUS has drawn attention for its potential to modulate brain activity in adults.•TUS may induce neuroplasticity, potentially transforming HIE treatment in newborns.
Perinatal hypoxic-ischemic encephalopathy (HIE) is the most common cause of neonatal encephalopathy, accounting for over half of all cases and the consequences of HIE can be devastating, making it one of the most severe perinatal complications. Therapeutic hypothermia has been shown to offer neuroprotection by reducing metabolic demand and slowing the cascade of injury processes. However, despite its benefits, therapeutic hypothermia has only modestly improved neurodevelopmental outcomes, indicating a major need for additional therapeutic approaches. Low-intensity transcranial ultrasound stimulation (TUS) is an emerging non-invasive brain stimulation technique for focally modulating specific brain regions that has recently drawn attention for its potential to modulate brain activity and promote neuroplasticity. The capacity of TUS to induce neuroplasticity through specific sonication parameters has been demonstrated in adult patients. Leveraging TUS to enhance functional connectivity and inhibit GABAergic systems within the injured thalami holds promise for inducing neuroplasticity in neonates with HIE. We hypothesize that enhancing thalamocortical functional connectivity and reducing local GABA levels through the use of TUS could potentially improve neurodevelopmental outcomes in neonates with HIE who have sustained thalamic injury and aim to test this hypothesis. Testing of the hypothesis will be conducted with a comprehensive assessment of safety and feasibility in neonates through a Phase I study, followed by further clinical studies to evaluate efficacy.
Aerobic exercise improves cognitive and motor function by inducing neural changes detected using molecular, cellular, and systems level neuroscience techniques. This review unifies the knowledge ...gained across various neuroscience techniques to provide a comprehensive profile of the neural mechanisms that mediate exercise-induced neuroplasticity. Using a model of exercise-induced neuroplasticity, this review emphasizes the sequence of neural events that accompany exercise, and ultimately promote changes in human performance. This is achieved by differentiating between neuroplasticity induced by acute versus chronic aerobic exercise. Furthermore, this review emphasizes experimental considerations that influence the opportunity to observe exercise-induced neuroplasticity in humans. These include modifiable factors associated with the exercise intervention and nonmodifiable factors such as biological sex, ovarian hormones, genetic variations, and fitness level. To maximize the beneficial effects of exercise in health, disease, and following injury, future research should continue to explore the mechanisms that mediate exercise-induced neuroplasticity. This review identifies some fundamental gaps in knowledge that may serve to guide future research in this area.
The synapse is the focus of experimental research and theory on the cellular mechanisms of nervous system plasticity and learning, but recent research is expanding the consideration of plasticity ...into new mechanisms beyond the synapse, notably including the possibility that conduction velocity could be modifiable through changes in myelin to optimize the timing of information transmission through neural circuits. This concept emerges from a confluence of brain imaging that reveals changes in white matter in the human brain during learning, together with cellular studies showing that the process of myelination can be influenced by action potential firing in axons. This Opinion article summarizes the new research on activity-dependent myelination, explores the possible implications of these studies and outlines the potential for new research.
Astrocyte roles in traumatic brain injury Burda, Joshua E.; Bernstein, Alexander M.; Sofroniew, Michael V.
Experimental neurology,
01/2016, Letnik:
275, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Astrocytes sense changes in neural activity and extracellular space composition. In response, they exert homeostatic mechanisms critical for maintaining neural circuit function, such as buffering ...neurotransmitters, modulating extracellular osmolarity and calibrating neurovascular coupling. In addition to upholding normal brain activities, astrocytes respond to diverse forms of brain injury with heterogeneous and progressive changes of gene expression, morphology, proliferative capacity and function that are collectively referred to as reactive astrogliosis. Traumatic brain injury (TBI) sets in motion complex events in which noxious mechanical forces cause tissue damage and disrupt central nervous system (CNS) homeostasis, which in turn trigger diverse multi-cellular responses that evolve over time and can lead either to neural repair or secondary cellular injury. In response to TBI, astrocytes in different cellular microenvironments tune their reactivity to varying degrees of axonal injury, vascular disruption, ischemia and inflammation. Here we review different forms of TBI-induced astrocyte reactivity and the functional consequences of these responses for TBI pathobiology. Evidence regarding astrocyte contribution to post-traumatic tissue repair and synaptic remodeling is examined, and the potential for targeting specific aspects of astrogliosis to ameliorate TBI sequelae is considered.
•Astrocytes respond to diverse forms of TBI with changes of gene expression, morphology, proliferation and function.•Astrocytes tune their reactivity to varying degrees of axonal and vascular injury, ischemia and inflammation after TBI.•Astrocytes regulate brain inflammation and blood-brain barrier permeability after TBI.•Astrocytes significantly contribute to post-traumatic tissue repair and synaptic remodeling following TBI.
Many studies have revealed the structural or functional brain changes induced by occupational factors. However, it remains largely unknown how occupation-related connectivity shapes the brain. In ...this paper, we denote occupational neuroplasticity as the neuroplasticity that takes place to satisfy the occupational requirements by extensively professional training and to accommodate the long-term, professional work of daily life, and a critical review of occupational neuroplasticity related to the changes in brain structure and functional networks has been primarily presented. Furthermore, meta-analysis revealed a neurophysiological mechanism of occupational neuroplasticity caused by professional experience. This meta-analysis of functional neuroimaging studies showed that experts displayed stronger activation in the left precentral gyrus Brodmann area (BA)6, left middle frontal gyrus (BA6), and right inferior frontal gyrus (BA9) than novices, while meta-analysis of structural studies suggested that experts had a greater gray matter volume in the bilateral superior temporal gyrus (BA22) and right putamen than novices. Together, these findings not only expand the current understanding of the common neurophysiological basis of occupational neuroplasticity across different occupations and highlight some possible targets for neural modulation of occupational neuroplasticity but also provide a new perspective for occupational science research.
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