scholarly journals A Common Language: How Neuroimmunological Cross Talk Regulates Adult Hippocampal Neurogenesis

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Odette Leiter ◽  
Gerd Kempermann ◽  
Tara L. Walker
Keyword(s):  
Immune System ◽  
Adult Neurogenesis ◽  
Immune Cells ◽  
Hippocampal Neurogenesis ◽  
Adult Brain ◽  
Adult Hippocampal Neurogenesis ◽  
Normal Brain ◽  
Intrinsic Cues ◽  
Normal Brain Function ◽  
The Brain

Immune regulation of the brain is generally studied in the context of injury or disease. Less is known about how the immune system regulates the brain during normal brain function. Recent work has redefined the field of neuroimmunology and, as long as their recruitment and activation are well regulated, immune cells are now known to have protective properties within the central nervous system in maintaining brain health. Adult neurogenesis, the process of new neuron generation in the adult brain, is highly plastic and regulated by diverse extrinsic and intrinsic cues. Emerging research has shown that immune cells and their secreted factors can influence adult neurogenesis, both under baseline conditions and during conditions known to change neurogenesis levels, such as aging and learning in an enriched environment. This review will discuss how, under nonpathological conditions, the immune system can interact with the neural stem cells to regulate adult neurogenesis with particular focus on the hippocampus—a region crucial for learning and memory.

scholarly journals Vitamin C In Neuropsychiatry

2015 ◽  
Vol 16 (2) ◽  
pp. 157-161 ◽  
Author(s):  
Dragan M. Pavlović ◽  
Merdin Š. Markišić ◽  
Aleksandra M. Pavlović
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
The Body ◽  
Adult Brain ◽  
Normal Brain ◽  
Positive Effects ◽  
Normal Brain Function ◽  
High Concentrations ◽  
High Doses ◽  
The Brain

Abstract Vitamins are necessary factors in human development and normal brain function. Vitamin C is a hydrosoluble compound that humans cannot produce; therefore, we are completely dependent on food intake for vitamin C. Ascorbic acid is an important antioxidative agent and is present in high concentrations in neurons and is also crucial for collagen synthesis throughout the body. Ascorbic acid has a role in modulating many essential neurotransmitters, enables neurogenesis in adult brain and protects cells against infection. While SVCT1 enables the absorption of vitamin C in the intestine, SVCT2 is primarily located in the brain. Ascorbate deficiency is classically expressed as scurvy, which is lethal if not treated. However, subclinical deficiencies are probably much more frequent. Potential fields of vitamin C therapy are in neurodegenerative, cerebrovascular and affective diseases, cancer, brain trauma and others. For example, there is some data on its positive effects in Alzheimer’s disease. Various dosing regimes are used, but ascorbate is safe, even in high doses for protracted periods. Better designed studies are needed to elucidate all of the potential therapeutic roles of vitamin C.

Adult hippocampal neurogenesis: an important target associated with antidepressant effects of exercise

2017 ◽  
Vol 28 (7) ◽  
pp. 693-703 ◽  
Author(s):  
Lina Sun ◽  
Qingshan Sun ◽  
Jinshun Qi
Keyword(s):  
Adult Neurogenesis ◽  
Healthy Lifestyle ◽  
Brain Plasticity ◽  
Treatment Method ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Brain Functions ◽  
Antidepressant Effects ◽  
Exercise Activity ◽  
The Brain

AbstractDepression is a prevalent devastating mental disorder that affects the normal life of patients and brings a heavy burden to whole society. Although many efforts have been made to attenuate depressive/anxiety symptoms, the current clinic antidepressants have limited effects. Scientists have long been making attempts to find some new strategies that can be applied as the alternative antidepressant therapy. Exercise, a widely recognized healthy lifestyle, has been suggested as a therapy that can relieve psychiatric stress. However, how exercise improves the brain functions and reaches the antidepressant target needs systematic summarization due to the complexity and heterogeneous feature of depression. Brain plasticity, especially adult neurogenesis in the hippocampus, is an important neurophysiology to facilitate animals for neurogenesis can occur in not only humans. Many studies indicated that an appropriate level of exercise can promote neurogenesis in the adult brains. In this article, we provide information about the antidepressant effects of exercise and its implications in adult neurogenesis. From the neurogenesis perspective, we summarize evidence about the effects of exercise in enhancing neurogenesis in the hippocampus through regulating growth factors, neurotrophins, neurotransmitters and metabolism as well as inflammations. Taken together, a large number of published works indicate the multiple benefits of exercise in the brain functions of animals, particularly brain plasticity like neurogenesis and synaptogenesis. Therefore, a new treatment method for depression therapy can be developed by regulating the exercise activity.

scholarly journals Pericytes Across the Lifetime in the Central Nervous System

2021 ◽  
Vol 15 ◽  
Author(s):  
Hannah C. Bennett ◽  
Yongsoo Kim
Keyword(s):  
Review Article ◽  
Developmental Trajectory ◽  
Adult Brain ◽  
Normal Brain ◽  
Major Life ◽  
Perivascular Cell ◽  
Normal Brain Function ◽  
And Migration ◽  
And Function ◽  
The Brain

The pericyte is a perivascular cell type that encapsulates the microvasculature of the brain and spinal cord. Pericytes play a crucial role in the development and maintenance of the blood-brain barrier (BBB) and have a multitude of important functions in the brain. Recent evidence indicates that pericyte impairment has been implicated in neurovascular pathology associated with various human diseases such as diabetes mellitus, Alzheimer’s disease (AD), and stroke. Although the pericyte is essential for normal brain function, knowledge about its developmental trajectory and anatomical distribution is limited. This review article summarizes the scientific community’s current understanding of pericytes’ regional heterogeneity in the brain and their changes during major life stages. More specifically, this review article focuses on pericyte differentiation and migration during brain development, regional population differences in the adult brain, and changes during normal and pathological aging. Most of what is known about pericytes come from studies of the cerebral cortex and hippocampus. Therefore, we highlight the need to expand our understanding of pericyte distribution and function in the whole brain to better delineate this cell type’s role in the normal brain and pathological conditions.

Adult Neurogenesis: Lessons from Crayfish and the Elephant in the Room

2016 ◽  
Vol 87 (3) ◽  
pp. 146-155 ◽  
Author(s):  
Barbara S. Beltz ◽  
Georg Brenneis ◽  
Jeanne L. Benton
Keyword(s):  
Stem Cells ◽  
Immune System ◽  
Neural Stem Cells ◽  
Adult Neurogenesis ◽  
Adult Brain ◽  
Neural Precursor ◽  
Neural Precursors ◽  
Neurogenic Niche ◽  
Fetal Microchimerism ◽  
The Brain

The 1st-generation neural precursors in the crustacean brain are functionally analogous to neural stem cells in mammals. Their slow cycling, migration of their progeny, and differentiation of their descendants into neurons over several weeks are features of the neural precursor lineage in crayfish that also characterize adult neurogenesis in mammals. However, the 1st-generation precursors in crayfish do not self-renew, contrasting with conventional wisdom that proposes the long-term self-renewal of adult neural stem cells. Nevertheless, the crayfish neurogenic niche, which contains a total of 200-300 cells, is never exhausted and neurons continue to be produced in the brain throughout the animal's life. The pool of neural precursors in the niche therefore cannot be a closed system, and must be replenished from an extrinsic source. Our in vitro and in vivo data show that cells originating in the innate immune system (but not other cell types) are attracted to and incorporated into the neurogenic niche, and that they express a niche-specific marker, glutamine synthetase. Further, labeled hemocytes that undergo adoptive transfer to recipient crayfish generate cells in neuronal clusters in the olfactory pathway of the adult brain. These hemocyte descendants express appropriate neurotransmitters and project to target areas typical of neurons in these regions. These studies indicate that under natural conditions, the immune system provides neural precursors supporting adult neurogenesis in the crayfish brain, challenging the canonical view that ectodermal tissues generating the embryonic nervous system are the sole source of neurons in the adult brain. However, these are not the first studies that directly implicate the immune system as a source of neural precursor cells. Several types of data in mammals, including adoptive transfers of bone marrow or stem cells as well as the presence of fetal microchimerism, suggest that there must be a population of cells that are able to access the brain and generate new neurons in these species.

scholarly journals Pro-NGF Disrupts Adult Neurogenesis in Humans and Mice Affected by Alzheimer's Disease

2021 ◽  
Author(s):  
Bolanle Olabiyi ◽  
Catherine Fleitas ◽  
Bahira Zammou ◽  
Isidro Ferrer ◽  
Claire Rampon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Adult Neurogenesis ◽  
Neutralizing Antibodies ◽  
Hippocampal Neurogenesis ◽  
Adult Brain ◽  
Adult Hippocampal Neurogenesis ◽  
Neurotrophin Receptor ◽  
Morris Water Maze Test ◽  
Healthy Humans

Abstract In recent decades, neurogenesis in adult brain has been well demonstrated in a number of animal species, including humans. Interestingly, work with rodents has shown that adult neurogenesis in the dentate gyrus (DG) of the hippocampus is vital for some cognitive aspects, as increasing neurogenesis improves memory while its disruption triggers the opposite effect. Adult neurogenesis declines with age and has been suggested to play a role in impaired progressive learning and memory loss seen in Alzheimer’s disease (AD). Therefore, therapeutic strategies designed to boost adult hippocampal neurogenesis may be beneficial for the treatment of AD. The precursor forms of neurotrophins, such as pro-NGF, display remarkable increase during AD in the hippocampus and entorhinal cortex. In contrast to mature NGF, pro-NGF exerts adverse functions in survival, proliferation and differentiation. Hence, we hypothesized that pro-NGF and its receptor p75NTR contribute to disrupting adult hippocampal neurogenesis during AD. In this study, we took advantage of the availability of mouse models of AD (APP/PS1) and AD human samples to address the role of pro-NGF/p75NTR signalling in different aspects of adult neurogenesis. Neuroprogenitors of adult mice and human DG samples were identified by immunofluorescence with doublecortin (DCX) antibodies. Interestingly, DCX + progenitors in healthy humans and control animals express p75 neurotrophin receptor (p75NTR). However, this expression is notably decreased in AD conditions. In APP/PS1 mice, memory and cognition were severely impaired. In order to assess the contribution of the pro-NGF/p75NTR pathway to these memory deficits, we injected pro-NGF neutralizing antibodies (ANTI-PRONGF) into the DG of control and APP/PS1 mice which memory was evaluated in Morris water maze test. We observed that anti-pro-NGF injection significantly improved the performance of APP/PS1 animals, but not controls. Interestingly, improved memory in APP/PS1 animals after injection of ANTI-PRONGF correlated with an increase in DCX + progenitors in the DG region of these animals. In summary, our results suggest that pro-NGF is involved in disrupting spatial memory in AD, at least in part by blocking adult neurogenesis. Moreover, we propose that adult neurogenesis alteration could serve as alternative approach towards understanding AD pathology, and additionally offer pro-NGF/p75NTR signalling as a promising therapeutic target.

scholarly journals Immune Regulation of Adult Neurogenic Niches in Health and Disease

2021 ◽  
Vol 14 ◽  
Author(s):  
Sana Chintamen ◽  
Fatima Imessadouene ◽  
Steven G. Kernie
Keyword(s):  
Immune Cells ◽  
Hippocampal Neurogenesis ◽  
Adult Brain ◽  
Adult Hippocampal Neurogenesis ◽  
Pharmacological Intervention ◽  
Mammalian Brain ◽  
Critical Periods ◽  
Promising Therapeutic Approach ◽  
Health And Disease

Microglia regulate neuronal development during embryogenesis, postnatal development, and in specialized microenvironments of the adult brain. Recent evidence demonstrates that in adulthood, microglia secrete factors which modulate adult hippocampal neurogenesis by inhibiting cell proliferation and survival both in vitro and in vivo, maintaining a balance between cell division and cell death in neurogenic niches. These resident immune cells also shape the nervous system by actively pruning synapses during critical periods of learning and engulfing excess neurons. In neurodegenerative diseases, aberrant microglial activity can impede the proper formation and prevent the development of appropriate functional properties of adult born granule cells. Ablating microglia has been presented as a promising therapeutic approach to alleviate the brain of maladaptive immune response. Here, we review key mechanisms through which the immune system actively shapes neurogenic niches throughout the lifespan of the mammalian brain in both health and disease. We discuss how interactions between immune cells and developing neurons may be leveraged for pharmacological intervention and as a means to preserve adult neurogenesis.

scholarly journals proNGF Involvement in the Adult Neurogenesis Dysfunction in Alzheimer’s Disease

2021 ◽  
Vol 22 (19) ◽  
pp. 10744
Author(s):  
Bolanle Fatimat Olabiyi ◽  
Catherine Fleitas ◽  
Bahira Zammou ◽  
Isidro Ferrer ◽  
Claire Rampon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Adult Neurogenesis ◽  
Neutralizing Antibodies ◽  
Hippocampal Neurogenesis ◽  
Adult Brain ◽  
Adult Hippocampal Neurogenesis ◽  
Neurotrophin Receptor ◽  
Morris Water Maze Test ◽  
Healthy Humans

In recent decades, neurogenesis in the adult brain has been well demonstrated in a number of animal species, including humans. Interestingly, work with rodents has shown that adult neurogenesis in the dentate gyrus (DG) of the hippocampus is vital for some cognitive aspects, as increasing neurogenesis improves memory, while its disruption triggers the opposite effect. Adult neurogenesis declines with age and has been suggested to play a role in impaired progressive learning and memory loss seen in Alzheimer’s disease (AD). Therefore, therapeutic strategies designed to boost adult hippocampal neurogenesis may be beneficial for the treatment of AD. The precursor forms of neurotrophins, such as pro-NGF, display remarkable increase during AD in the hippocampus and entorhinal cortex. In contrast to mature NGF, pro-NGF exerts adverse functions in survival, proliferation, and differentiation. Hence, we hypothesized that pro-NGF and its p75 neurotrophin receptor (p75NTR) contribute to disrupting adult hippocampal neurogenesis during AD. To test this hypothesis, in this study, we took advantage of the availability of mouse models of AD (APP/PS1), which display memory impairment, and AD human samples to address the role of pro-NGF/p75NTR signaling in different aspects of adult neurogenesis. First, we observed that DG doublecortin (DCX) + progenitors express p75NTR both, in healthy humans and control animals, although the percentage of DCX+ cells are significantly reduced in AD. Interestingly, the expression of p75NTR in these progenitors is significantly decreased in AD conditions compared to controls. In order to assess the contribution of the pro-NGF/p75NTR pathway to the memory deficits of APP/PS1 mice, we injected pro-NGF neutralizing antibodies (anti-proNGF) into the DG of control and APP/PS1 mice and animals are subjected to a Morris water maze test. Intriguingly, we observed that anti-pro-NGF significantly restored memory performance of APP/PS1 animals and significantly increase the percentage of DCX+ progenitors in the DG region of these animals. In summary, our results suggest that pro-NGF is involved in disrupting spatial memory in AD, at least in part by blocking adult neurogenesis. Moreover, we propose that adult neurogenesis alteration should be taken into consideration for better understanding of AD pathology. Additionally, we provide a new molecular entry point (pro-NGF/p75NTR signaling) as a promising therapeutic target in AD.

scholarly journals Mitochondrial and Autophagic Regulation of Adult Neurogenesis in the Healthy and Diseased Brain

2021 ◽  
Vol 22 (7) ◽  
pp. 3342
Author(s):  
Hansruedi Büeler
Keyword(s):  
Stem Cell ◽  
Mood Disorders ◽  
Adult Neurogenesis ◽  
Cell Function ◽  
Natural Aging ◽  
Hippocampal Neurogenesis ◽  
Adult Brain ◽  
Adult Hippocampal Neurogenesis ◽  
Induced Mood ◽  
Newborn Neurons

Adult neurogenesis is a highly regulated process during which new neurons are generated from neural stem cells in two discrete regions of the adult brain: the subventricular zone of the lateral ventricle and the subgranular zone of the dentate gyrus in the hippocampus. Defects of adult hippocampal neurogenesis have been linked to cognitive decline and dysfunction during natural aging and in neurodegenerative diseases, as well as psychological stress-induced mood disorders. Understanding the mechanisms and pathways that regulate adult neurogenesis is crucial to improving preventative measures and therapies for these conditions. Accumulating evidence shows that mitochondria directly regulate various steps and phases of adult neurogenesis. This review summarizes recent findings on how mitochondrial metabolism, dynamics, and reactive oxygen species control several aspects of adult neural stem cell function and their differentiation to newborn neurons. It also discusses the importance of autophagy for adult neurogenesis, and how mitochondrial and autophagic dysfunction may contribute to cognitive defects and stress-induced mood disorders by compromising adult neurogenesis. Finally, I suggest possible ways to target mitochondrial function as a strategy for stem cell-based interventions and treatments for cognitive and mood disorders.

A Survey on Detection and Classification of Brain Tumor Using Image Processing Techniques

2020 ◽  
pp. 967-973
Author(s):  
V. Deepika ◽  
T. Rajasenbagam
Keyword(s):  
Image Processing ◽  
Brain Tumor ◽  
Soft Tissues ◽  
Tumor Detection ◽  
Tumor Classification ◽  
Normal Brain ◽  
Image Processing Techniques ◽  
Normal Brain Function ◽  
Processing Techniques ◽  
The Brain

A brain tumor is an uncontrolled growth of abnormal brain tissue that can interfere with normal brain function. Although various methods have been developed for brain tumor classification, tumor detection and multiclass classification remain challenging due to the complex characteristics of the brain tumor. Brain tumor detection and classification are one of the most challenging and time-consuming tasks in the processing of medical images. MRI (Magnetic Resonance Imaging) is a visual imaging technique, which provides a information about the soft tissues of the human body, which helps identify the brain tumor. Proper diagnosis can prevent a patient's health to some extent. This paper presents a review of various detection and classification methods for brain tumor classification using image processing techniques.

Is adult hippocampal neurogenesis really relevant for the treatment of psychiatric disorders?

2020 ◽  
Vol 18 ◽  
Author(s):  
Marco Carli ◽  
Stefano Aringhieri ◽  
Shivakumar Kolachalam ◽  
Biancamaria Longoni ◽  
Giovanna Grenno ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Emotional Processing ◽  
Imaging Techniques ◽  
Hippocampal Neurogenesis ◽  
Adult Brain ◽  
Adult Hippocampal Neurogenesis ◽  
Mood Stabilizers ◽  
Post Traumatic Stress ◽  
Newborn Neurons ◽  
Hippocampal Circuitry

: Adult neurogenesis consists in the generation of newborn neurons from neural stem cells taking place in the adult brain. In mammals, this process is limited to very few areas of the brain, and one of these neurogenic niches is the subgranular layer of the dentate gyrus (DG) of the hippocampus. Adult newborn neurons are generated from quiescent neural progenitors (QNPs), which differentiate through different steps into mature granule cells (GCs), to be finally integrated into the existing hippocampal circuitry. In animal models, adult hippocampal neurogenesis (AHN) is relevant for pattern discrimination, cognitive flexibility, emotional processing and resilience to stressful situations. Imaging techniques allow to visualize newborn neurons within the hippocampus through all their stages of development and differentiation. In humans, the evidence of AHN is more challenging, and, based on recent findings, it persists through the adulthood, even if it declines with age. Whether this process has an important role in human brain function and how it integrates into the existing hippocampal circuitry is still a matter of exciting debate. Importantly, AHN deficiency has been proposed to be relevant in many psychiatric disorders, including mood disorders, anxiety, post-traumatic stress disorder and schizophrenia. This review aims to investigate how AHN is altered in different psychiatric conditions and how pharmacological treatments can rescue this process. In fact, many psychoactive drugs, such as antidepressants, mood stabilizers and atypical antipsychotics (AAPs), can boost AHN with different results. In addition, some non-pharmacological approaches are discussed as well.

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