scholarly journals Adult Neurogenesis in the Drosophila Brain: The Evidence and the Void

2020 ◽  
Vol 21 (18) ◽  
pp. 6653
Author(s):  
Guiyi Li ◽  
Alicia Hidalgo
Keyword(s):  
Adult Neurogenesis ◽  
Genetic Manipulation ◽  
Brain Plasticity ◽  
Fruit Fly ◽  
Cell Number ◽  
Adult Brain ◽  
Proliferating Cells ◽  
Drosophila Brain ◽  
The Central Nervous System ◽  
The Brain

Establishing the existence and extent of neurogenesis in the adult brain throughout the animals including humans, would transform our understanding of how the brain works, and how to tackle brain damage and disease. Obtaining convincing, indisputable experimental evidence has generally been challenging. Here, we revise the state of this question in the fruit-fly Drosophila. The developmental neuroblasts that make the central nervous system and brain are eliminated, either through apoptosis or cell cycle exit, before the adult fly ecloses. Despite this, there is growing evidence that cell proliferation can take place in the adult brain. This occurs preferentially at, but not restricted to, a critical period. Adult proliferating cells can give rise to both glial cells and neurons. Neuronal activity, injury and genetic manipulation in the adult can increase the incidence of both gliogenesis and neurogenesis, and cell number. Most likely, adult glio- and neuro-genesis promote structural brain plasticity and homeostasis. However, a definitive visualisation of mitosis in the adult brain is still lacking, and the elusive adult progenitor cells are yet to be identified. Resolving these voids is important for the fundamental understanding of any brain. Given its powerful genetics, Drosophila can expedite discovery into mammalian adult neurogenesis in the healthy and diseased brain.

Neurodevelopment

2020 ◽  
pp. 91-100
Author(s):  
Karl Zilles ◽  
Nicola Palomero-Gallagher
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Neural Tube ◽  
Neural Plate ◽  
Adult Brain ◽  
The Central Nervous System ◽  
Specialized Region ◽  
The Brain ◽  
Rostral Part ◽  
Human Nervous System

The pre- and post-natal development of the human nervous system is briefly described, with special emphasis on the brain, particularly the cerebral and cerebellar cortices. The central nervous system originates from a specialized region of the ectoderm—the neural plate—which develops into the neural tube. The rostral part of the neural tube forms the adult brain, whereas the caudal part (behind the fifth somite) differentiates into the spinal cord. The embryonic brain has three vesicular enlargements: the forebrain, the midbrain, and the hindbrain. The histogenesis of the spinal cord, hindbrain, cerebellum, and cerebral cortex, including myelination, is discussed. The chapter closes with a description of the development of the hemispheric shape and the formation of gyri.

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 Tissue-specific expression of the heat shock protein HSP27 during Drosophila melanogaster development.

1990 ◽  
Vol 111 (3) ◽  
pp. 817-828 ◽  
Author(s):  
D Pauli ◽  
C H Tonka ◽  
A Tissieres ◽  
A P Arrigo
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Stress Protein ◽  
Pupal Stage ◽  
Adult Brain ◽  
Proliferating Cells ◽  
Specific Expression ◽  
The Central Nervous System

The alpha-crystallin-related heat shock (stress) protein hsp27 is expressed in absence of heat shock during Drosophila melanogaster development. Here, we describe the tissue distribution of this protein using an immunoaffinity-purified antibody. In embryos, hsp27 translated from maternal RNA is uniformly distributed, except in the yolk. During the first, second, and early third larval stages, hsp27 expression is restricted to the brain and the gonads. These tissues are characterized by a high level of proliferating cells. In late third instar larvae and early pupae, in addition to the central nervous system and the gonads, all the imaginal discs synthesize hsp27. The disc expression seems restricted to the beginning of their differentiation since it disappears during the second half of the pupal stage: no more hsp27 is observed in the disc-derived adult organs. In adults, hsp27 is still present in some regions of the central nervous system, and is also expressed in the male and female germ lines where it accumulates in mature sperm and oocytes. The transcript and the protein accumulate in oocytes since the onset of vitellogenesis with a uniform distribution similar to that found in embryos. The adult germ lines transcribe hsp27 gene while no transcript is detected in the late pupal and adult brain. These results suggest multiple roles of hsp27 during Drosophila development which may be related to both the proliferative and differentiated states of the tissues.

scholarly journals Cellular Mechanisms Participating in Brain Repair of Adult Zebrafish and Mammals After Injury

2020 ◽  
Author(s):  
Batoul Ghaddar ◽  
Luisa Lübke ◽  
David COURET ◽  
Sepand Rastegar ◽  
Nicolas Diotel
Keyword(s):  
Stem Cells ◽  
Adult Neurogenesis ◽  
Brain Plasticity ◽  
Adult Zebrafish ◽  
Cellular Mechanisms ◽  
Regenerative Capacity ◽  
Brain Repair ◽  
Cellular Events ◽  
Similarities And Differences ◽  
The Brain

Adult neurogenesis is an evolutionary conserved process occurring in all vertebrates. However, striking differences are observed between the taxa, considering the number of neurogenic niches, the neural stem cell (NSC) identity and brain plasticity under constitutive and injury-induced conditions. Zebrafish has become a popular model for the investigation of the molecular and cellular mechanisms involved in adult neurogenesis. Compared to mammals, the adult zebrafish displays a high number of neurogenic niches distributed throughout the brain. Furthermore, it exhibits a strong regenerative capacity without scar formation or any obvious disabilities. In this review, we will first discuss the similarities and differences regarding (i) the distribution of neurogenic niches in the brain of adult zebrafish and mammals (mainly mouse) and (ii) the nature of the neural stem cells within the main telencephalic niches. In the second part, we will describe the cascade of cellular events occurring after telencephalic injury in zebrafish and mouse. Our study clearly shows that most early events happening right after the brain injury are shared between zebrafish and mouse including cell death, microglia and oligodendrocyte recruitment, as well as injury-induced neurogenesis. In mammals one of the consequences following an injury is the formation of a glial scar that is persistent. This is not the case in zebrafish, which may be one of the main reasons that zebrafish display a higher regenerative capacity.

scholarly journals Adult Neurogenesis: A Story Ranging from Controversial New Neurogenic Areas and Human Adult Neurogenesis to Molecular Regulation

2021 ◽  
Vol 22 (21) ◽  
pp. 11489
Author(s):  
Perla Leal-Galicia ◽  
María Elena Chávez-Hernández ◽  
Florencia Mata ◽  
Jesús Mata-Luévanos ◽  
Luis Miguel Rodríguez-Serrano ◽  
...  
Keyword(s):  
Adult Neurogenesis ◽  
Molecular Mechanisms ◽  
Adult Brain ◽  
Human Adult ◽  
Open Questions ◽  
Division Process ◽  
Technical Issues ◽  
Functional Relevance ◽  
Local Circuitry ◽  
The Brain

The generation of new neurons in the adult brain is a currently accepted phenomenon. Over the past few decades, the subventricular zone and the hippocampal dentate gyrus have been described as the two main neurogenic niches. Neurogenic niches generate new neurons through an asymmetric division process involving several developmental steps. This process occurs throughout life in several species, including humans. These new neurons possess unique properties that contribute to the local circuitry. Despite several efforts, no other neurogenic zones have been observed in many years; the lack of observation is probably due to technical issues. However, in recent years, more brain niches have been described, once again breaking the current paradigms. Currently, a debate in the scientific community about new neurogenic areas of the brain, namely, human adult neurogenesis, is ongoing. Thus, several open questions regarding new neurogenic niches, as well as this phenomenon in adult humans, their functional relevance, and their mechanisms, remain to be answered. In this review, we discuss the literature and provide a compressive overview of the known neurogenic zones, traditional zones, and newly described zones. Additionally, we will review the regulatory roles of some molecular mechanisms, such as miRNAs, neurotrophic factors, and neurotrophins. We also join the debate on human adult neurogenesis, and we will identify similarities and differences in the literature and summarize the knowledge regarding these interesting topics.

scholarly journals Broadening the functional and evolutionary understanding of postnatal neurogenesis using reptilian models

2020 ◽  
Vol 223 (15) ◽  
pp. jeb210542
Author(s):  
Lara D. LaDage
Keyword(s):  
Adult Neurogenesis ◽  
Brain Plasticity ◽  
Adult Brain ◽  
Postnatal Neurogenesis ◽  
Late 20Th Century ◽  
Neural Processes ◽  
Wide Range ◽  
Evolutionary Context ◽  
Similarities And Differences ◽  
Taxonomic Groups

ABSTRACTThe production of new neurons in the brains of adult animals was first identified by Altman and Das in 1965, but it was not until the late 20th century when methods for visualizing new neuron production improved that there was a dramatic increase in research on neurogenesis in the adult brain. We now know that adult neurogenesis is a ubiquitous process that occurs across a wide range of taxonomic groups. This process has largely been studied in mammals; however, there are notable differences between mammals and other taxonomic groups in how, why and where new neuron production occurs. This Review will begin by describing the processes of adult neurogenesis in reptiles and identifying the similarities and differences in these processes between reptiles and model rodent species. Further, this Review underscores the importance of appreciating how wild-caught animals vary in neurogenic properties compared with laboratory-reared animals and how this can be used to broaden the functional and evolutionary understanding of why and how new neurons are produced in the adult brain. Studying variation in neural processes across taxonomic groups provides an evolutionary context to adult neurogenesis while also advancing our overall understanding of neurogenesis and brain plasticity.

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 Role of Neuroinflammation in Adult Neurogenesis and Alzheimer Disease: Therapeutic Approaches

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Almudena Fuster-Matanzo ◽  
María Llorens-Martín ◽  
Félix Hernández ◽  
Jesús Avila
Keyword(s):  
Immune Response ◽  
Alzheimer Disease ◽  
Adult Neurogenesis ◽  
The Elderly ◽  
Therapeutic Approaches ◽  
Common Cause ◽  
The Central Nervous System ◽  
Chronic Activation ◽  
The Brain

Neuroinflammation, a specialized immune response that takes place in the central nervous system, has been linked to neurodegenerative diseases, and specially, it has been considered as a hallmark of Alzheimer disease, the most common cause of dementia in the elderly nowadays. Furthermore, neuroinflammation has been demonstrated to affect important processes in the brain, such as the formation of new neurons, commonly known as adult neurogenesis. For this, many therapeutic approaches have been developed in order to avoid or mitigate the deleterious effects caused by the chronic activation of the immune response. Considering this, in this paper we revise the relationships between neuroinflammation, Alzheimer disease, and adult neurogenesis, as well as the current therapeutic approaches that have been developed in the field.

scholarly journals Insight from animal models of environmentally driven epigenetic changes in the developing and adult brain

2016 ◽  
Vol 28 (4pt2) ◽  
pp. 1229-1243 ◽  
Author(s):  
Tiffany S. Doherty ◽  
Tania L. Roth
Keyword(s):  
Central Nervous System ◽  
Animal Models ◽  
Behavioral Outcomes ◽  
Adult Brain ◽  
Epigenetic Changes ◽  
Behavioral Deficits ◽  
The Central Nervous System ◽  
Brain And Behavior ◽  
And Behavior ◽  
The Brain

AbstractThe efforts of many neuroscientists are directed toward understanding the appreciable plasticity of the brain and behavior. In recent years, epigenetics has become a core of this focus as a prime mechanistic candidate for behavioral modifications. Animal models have been instrumental in advancing our understanding of environmentally driven changes to the epigenome in the developing and adult brain. This review focuses mainly on such discoveries driven by adverse environments along with their associated behavioral outcomes. While much of the evidence discussed focuses on epigenetics within the central nervous system, several peripheral studies in humans who have experienced significant adversity are also highlighted. As we continue to unravel the link between epigenetics and phenotype, discerning the complexity and specificity of epigenetic changes induced by environments is an important step toward understanding optimal development and how to prevent or ameliorate behavioral deficits bred by disruptive environments.

scholarly journals Links between Immune Cells from the Periphery and the Brain in the Pathogenesis of Epilepsy: A Narrative Review

2021 ◽  
Vol 22 (9) ◽  
pp. 4395
Author(s):  
Gaku Yamanaka ◽  
Shinichiro Morichi ◽  
Tomoko Takamatsu ◽  
Yusuke Watanabe ◽  
Shinji Suzuki ◽  
...  
Keyword(s):  
Immune Cell ◽  
Genetic Manipulation ◽  
Neurovascular Unit ◽  
Therapeutic Interventions ◽  
Research Directions ◽  
Cerebrovascular Dysfunction ◽  
Central Nervous Systems ◽  
The Central Nervous System ◽  
Time Required ◽  
The Brain

Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood–brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures.

Sign in / Sign up

Export Citation Format

Share Document