scholarly journals Proliferation, neurogenesis and regeneration in the non-mammalian vertebrate brain

2007 ◽  
Vol 363 (1489) ◽  
pp. 101-122 ◽  
Author(s):  
Jan Kaslin ◽  
Julia Ganz ◽  
Michael Brand
Keyword(s):  
Olfactory Bulb ◽  
Adult Neurogenesis ◽  
Brain Plasticity ◽  
Brain Regions ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Embryonic Neurogenesis ◽  
Vertebrate Brain ◽  
Multipotent Progenitor Cells

Post-embryonic neurogenesis is a fundamental feature of the vertebrate brain. However, the level of adult neurogenesis decreases significantly with phylogeny. In the first part of this review, a comparative analysis of adult neurogenesis and its putative roles in vertebrates are discussed. Adult neurogenesis in mammals is restricted to two telencephalic constitutively active zones. On the contrary, non-mammalian vertebrates display a considerable amount of adult neurogenesis in many brain regions. The phylogenetic differences in adult neurogenesis are poorly understood. However, a common feature of vertebrates (fish, amphibians and reptiles) that display a widespread adult neurogenesis is the substantial post-embryonic brain growth in contrast to birds and mammals. It is probable that the adult neurogenesis in fish, frogs and reptiles is related to the coordinated growth of sensory systems and corresponding sensory brain regions. Likewise, neurons are substantially added to the olfactory bulb in smell-oriented mammals in contrast to more visually oriented primates and songbirds, where much fewer neurons are added to the olfactory bulb. The second part of this review focuses on the differences in brain plasticity and regeneration in vertebrates. Interestingly, several recent studies show that neurogenesis is suppressed in the adult mammalian brain. In mammals, neurogenesis can be induced in the constitutively neurogenic brain regions as well as ectopically in response to injury, disease or experimental manipulations. Furthermore, multipotent progenitor cells can be isolated and differentiated in vitro from several otherwise silent regions of the mammalian brain. This indicates that the potential to recruit or generate neurons in non-neurogenic brain areas is not completely lost in mammals. The level of adult neurogenesis in vertebrates correlates with the capacity to regenerate injury, for example fish and amphibians exhibit the most widespread adult neurogenesis and also the greatest capacity to regenerate central nervous system injuries. Studying these phenomena in non-mammalian vertebrates may greatly increase our understanding of the mechanisms underlying regeneration and adult neurogenesis. Understanding mechanisms that regulate endogenous proliferation and neurogenic permissiveness in the adult brain is of great significance in therapeutical approaches for brain injury and disease.

Adult Neurogenesis: From Precursors to Network and Physiology

2005 ◽  
Vol 85 (2) ◽  
pp. 523-569 ◽  
Author(s):  
Djoher Nora Abrous ◽  
Muriel Koehl ◽  
Michel Le Moal
Keyword(s):  
Adult Neurogenesis ◽  
Brain Plasticity ◽  
Current Knowledge ◽  
Hippocampal Formation ◽  
Functional Integration ◽  
Brain Regions ◽  
Biological Properties ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Extrinsic Factors

The discovery that the adult mammalian brain creates new neurons from pools of stemlike cells was a breakthrough in neuroscience. Interestingly, this particular new form of structural brain plasticity seems specific to discrete brain regions, and most investigations concern the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampal formation (HF). Overall, two main lines of research have emerged over the last two decades: the first aims to understand the fundamental biological properties of neural stemlike cells (and their progeny) and the integration of the newly born neurons into preexisting networks, while the second focuses on understanding its relevance in brain functioning, which has been more extensively approached in the DG. Here, we propose an overview of the current knowledge on adult neurogenesis and its functional relevance for the adult brain. We first present an analysis of the methodological issues that have hampered progress in this field and describe the main neurogenic sites with their specificities. We will see that despite considerable progress, the levels of anatomic and functional integration of the newly born neurons within the host circuitry have yet to be elucidated. Then the intracellular mechanisms controlling neuronal fate are presented briefly, along with the extrinsic factors that regulate adult neurogenesis. We will see that a growing list of epigenetic factors that display a specificity of action depending on the neurogenic site under consideration has been identified. Finally, we review the progress accomplished in implicating neurogenesis in hippocampal functioning under physiological conditions and in the development of hippocampal-related pathologies such as epilepsy, mood disorders, and addiction. This constitutes a necessary step in promoting the development of therapeutic strategies.

scholarly journals The piRNA pathway sustains adult neurogenesis by repressing protein synthesis

2020 ◽  
Author(s):  
C. Gasperini ◽  
R. Pelizzoli ◽  
A. Lo Van ◽  
D. Mangoni ◽  
R.M. Cossu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Adult Neurogenesis ◽  
Neural Progenitor Cells ◽  
Brain Plasticity ◽  
Mammalian Brain ◽  
Loss Of Function ◽  
Transfer Rnas ◽  
Pirna Pathway

AbstractIn specific niches of the adult mammalian brain, neural progenitor cells (aNPCs) ensure lifelong neurogenesis. Proper regulation of this process entails important implications for brain plasticity and health. We report that Piwil2 (Mili) and PIWI-interacting RNAs (piRNAs) are abundantly expressed in aNPCs but depleted in their progeny in the adult mouse hippocampus. Loss of function of the piRNA pathway in aNPCs inhibited neurogenesis and increased reactive gliogenesis in vivo and in vitro. PiRNA pathway depletion in cultured aNPCs increased levels of 5S ribosomal RNA, transfer RNAs and mRNAs encoding regulators of translation, resulting in higher polyribosome density and protein synthesis upon differentiation. We propose that the piRNA pathway sustains adult neurogenesis by repressing translation in aNPCs.One sentence summaryThe piRNA pathway is enriched in neural precursors and essential for appropriate neurogenesis by modulating translation

scholarly journals An architectonic type principle in the development of laminar patterns of cortico-cortical connections

2021 ◽  
Author(s):  
Sarah F. Beul ◽  
Alexandros Goulas ◽  
Claus C. Hilgetag
Keyword(s):  
Structural Connectivity ◽  
Macaque Monkey ◽  
Brain Regions ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Cortical Connections ◽  
Cortical Projections ◽  
Structural Connections ◽  
High Degree ◽  
The Brain

AbstractStructural connections between cortical areas form an intricate network with a high degree of specificity. Many aspects of this complex network organization in the adult mammalian cortex are captured by an architectonic type principle, which relates structural connections to the architectonic differentiation of brain regions. In particular, the laminar patterns of projection origins are a prominent feature of structural connections that varies in a graded manner with the relative architectonic differentiation of connected areas in the adult brain. Here we show that the architectonic type principle is already apparent for the laminar origins of cortico-cortical projections in the immature cortex of the macaque monkey. We find that prenatal and neonatal laminar patterns correlate with cortical architectonic differentiation, and that the relation of laminar patterns to architectonic differences between connected areas is not substantially altered by the complete loss of visual input. Moreover, we find that the degree of change in laminar patterns that projections undergo during development varies in proportion to the relative architectonic differentiation of the connected areas. Hence, it appears that initial biases in laminar projection patterns become progressively strengthened by later developmental processes. These findings suggest that early neurogenetic processes during the formation of the brain are sufficient to establish the characteristic laminar projection patterns. This conclusion is in line with previously suggested mechanistic explanations underlying the emergence of the architectonic type principle and provides further constraints for exploring the fundamental factors that shape structural connectivity in the mammalian brain.

scholarly journals Neural stem cells: involvement in adult neurogenesis and CNS repair

2008 ◽  
Vol 363 (1500) ◽  
pp. 2111-2122 ◽  
Author(s):  
Hideyuki Okano ◽  
Kazunobu Sawamoto
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Cell Transplantation ◽  
Adult Neurogenesis ◽  
Embryonic Stem ◽  
Adult Brain ◽  
Therapeutic Interventions ◽  
Cell Transplantation Therapy ◽  
Transplantation Therapy

Recent advances in stem cell research, including the selective expansion of neural stem cells (NSCs) in vitro , the induction of particular neural cells from embryonic stem cells in vitro , the identification of NSCs or NSC-like cells in the adult brain and the detection of neurogenesis in the adult brain (adult neurogenesis), have laid the groundwork for the development of novel therapies aimed at inducing regeneration in the damaged central nervous system (CNS). There are two major strategies for inducing regeneration in the damaged CNS: (i) activation of the endogenous regenerative capacity and (ii) cell transplantation therapy. In this review, we summarize the recent findings from our group and others on NSCs, with respect to their role in insult-induced neurogenesis (activation of adult NSCs, proliferation of transit-amplifying cells, migration of neuroblasts and survival and maturation of the newborn neurons), and implications for therapeutic interventions, together with tactics for using cell transplantation therapy to treat the damaged CNS.

scholarly journals Mercury Toxicity and Neurogenesis in the Mammalian Brain

2021 ◽  
Vol 22 (14) ◽  
pp. 7520
Author(s):  
Louise C. Abbott ◽  
Fikru Nigussie
Keyword(s):  
Neural Networks ◽  
Progenitor Cells ◽  
Adult Neurogenesis ◽  
Neural Progenitor Cells ◽  
Mammalian Brain ◽  
Mercury Toxicity ◽  
Embryonic Neurogenesis ◽  
Programmed Death ◽  
Final Integration ◽  
Developing Neurons

The mammalian brain is formed from billions of cells that include a wide array of neuronal and glial subtypes. Neural progenitor cells give rise to the vast majority of these cells during embryonic, fetal, and early postnatal developmental periods. The process of embryonic neurogenesis includes proliferation, differentiation, migration, the programmed death of some newly formed cells, and the final integration of differentiated neurons into neural networks. Adult neurogenesis also occurs in the mammalian brain, but adult neurogenesis is beyond the scope of this review. Developing embryonic neurons are particularly susceptible to neurotoxicants and especially mercury toxicity. This review focused on observations concerning how mercury, and in particular, methylmercury, affects neurogenesis in the developing mammalian brain. We summarized information on models used to study developmental mercury toxicity, theories of pathogenesis, and treatments that could be used to reduce the toxic effects of mercury on developing neurons.

scholarly journals Relationships between dietary macronutrients and adult neurogenesis in the regulation of energy metabolism – CORRIGENDUM

2013 ◽  
Vol 111 (4) ◽  
pp. 755-755
Author(s):  
Marianne A. Yon ◽  
Suzanna L. Mauger ◽  
Lucy C. Pickavance
Keyword(s):  
Body Weight ◽  
Energy Metabolism ◽  
Adult Neurogenesis ◽  
Brain Regions ◽  
The Body ◽  
Adult Brain ◽  
Metabolic Dysfunction ◽  
Neurogenic Niche ◽  
Normal Limits ◽  
Simple Carbohydrates

Of the environmental factors which have an impact on body weight, nutrients are most influential. Within normal limits, hypothalamic and related neuronal populations correct perturbations in energy metabolism, to return the body to its nutritional set-point, either through direct response to nutrients or indirectly via peripheral appetite signals. Excessive intake of certain macronutrients, such as simple carbohydrates and SFA, can lead to obesity and attendant metabolic dysfunction, also reflected in alterations in structural plasticity, and, intriguingly, neurogenesis, in some of these brain regions. Neurogenesis, previously thought to occur only in the embryo, is now known to take place in the adult brain, dependent on numerous stimulating and inhibiting factors, including dietary components. Because of classic associations between neurogenesis and the hippocampus, in learning and cognition, this brain region has also been the focus of attention in the study of links between diet and neurogenesis. Recently, however, a more complete picture of this relationship has been building: not only has the hypothalamus been shown to satisfy the criteria for a neurogenic niche, but appetite-related mediators, including circulating hormones, such as leptin and ghrelin, pro-inflammatory cytokines and the endocannabinoid intracellular messengers, are also being examined for their potential role in mediating neurogenic responses to macronutrients. The present review draws together these observations and investigates whether n-3 PUFA may exert their attenuating effects on body weight through the stimulation of adult neurogenesis. Exploration of the effects of nutraceuticals on neurogenic brain regions may encourage the development of new rational therapies in the fight against obesity.

scholarly journals Imaging Subthreshold Voltage Oscillation With Cellular Resolution in the Inferior Olive in vitro

2020 ◽  
Vol 14 ◽  
Author(s):  
Kevin Dorgans ◽  
Bernd Kuhn ◽  
Marylka Yoe Uusisaari
Keyword(s):  
Inferior Olive ◽  
Brain Slices ◽  
Brain Regions ◽  
Mammalian Brain ◽  
Wide Field ◽  
Voltage Imaging ◽  
Subthreshold Oscillations ◽  
Cellular Resolution

Voltage imaging with cellular resolution in mammalian brain slices is still a challenging task. Here, we describe and validate a method for delivery of the voltage-sensitive dye ANNINE-6plus (A6+) into tissue for voltage imaging that results in higher signal-to-noise ratio (SNR) than conventional bath application methods. The not fully dissolved dye was injected into the inferior olive (IO) 0, 1, or 7 days prior to acute slice preparation using stereotactic surgery. We find that the voltage imaging improves after an extended incubation period in vivo in terms of labeled volume, homogeneous neuropil labeling with saliently labeled somata, and SNR. Preparing acute slices 7 days after the dye injection, the SNR is high enough to allow single-trial recording of IO subthreshold oscillations using wide-field (network-level) as well as high-magnification (single-cell level) voltage imaging with a CMOS camera. This method is easily adaptable to other brain regions where genetically-encoded voltage sensors are prohibitively difficult to use and where an ultrafast, pure electrochromic sensor, like A6+, is required. Due to the long-lasting staining demonstrated here, the method can be combined, for example, with deep-brain imaging using implantable GRIN lenses.

scholarly journals Spatiotemporal expression and transcriptional perturbations by long noncoding RNAs in the mouse brain

2015 ◽  
Vol 112 (22) ◽  
pp. 6855-6862 ◽  
Author(s):  
Loyal A. Goff ◽  
Abigail F. Groff ◽  
Martin Sauvageau ◽  
Zachary Trayes-Gibson ◽  
Diana B. Sanchez-Gomez ◽  
...  
Keyword(s):  
Neural Development ◽  
Expression Patterns ◽  
Noncoding Rnas ◽  
Brain Regions ◽  
Long Noncoding Rnas ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Endogenous Expression ◽  
Spatiotemporal Expression

Long noncoding RNAs (lncRNAs) have been implicated in numerous cellular processes including brain development. However, the in vivo expression dynamics and molecular pathways regulated by these loci are not well understood. Here, we leveraged a cohort of 13 lncRNA-null mutant mouse models to investigate the spatiotemporal expression of lncRNAs in the developing and adult brain and the transcriptome alterations resulting from the loss of these lncRNA loci. We show that several lncRNAs are differentially expressed both in time and space, with some presenting highly restricted expression in only selected brain regions. We further demonstrate altered regulation of genes for a large variety of cellular pathways and processes upon deletion of the lncRNA loci. Finally, we found that 4 of the 13 lncRNAs significantly affect the expression of several neighboring protein-coding genes in a cis-like manner. By providing insight into the endogenous expression patterns and the transcriptional perturbations caused by deletion of the lncRNA locus in the developing and postnatal mammalian brain, these data provide a resource to facilitate future examination of the specific functional relevance of these genes in neural development, brain function, and disease.

scholarly journals Neurogenesis in the adult brain functionally contributes to the maintenance of chronic neuropathic pain

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Linette Liqi Tan ◽  
Julieta Alfonso ◽  
Hannah Monyer ◽  
Rohini Kuner
Keyword(s):  
Adult Neurogenesis ◽  
Negative Mood ◽  
Well Being ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Chronic Neuropathic Pain ◽  
Pathological Pain ◽  
Psychiatric Conditions

AbstractMaladaptive adult neurogenesis in the mammalian brain has been associated with diverse behaviors including disrupted learning, negative mood disorders and psychiatric conditions. However, its functional role in the generation and maintenance of chronic pathological pain has not yet been elucidated. Using an inducible genetic deletion in vivo mouse model, different behavioural paradigms and home cage monitoring systems, we show that an absence of adult neurogenesis does not impact the development of neuropathic injury-induced peripheral nociceptive hypersensitivity, but rather promotes the recovery of pathological pain as well as improves parameters associated with the state of well-being of the injured mice. These results provide a mechanistic insight into the mechanisms of chronic pain and implicate neurogenic processes as a potential therapeutic target for reducing pain and improving the quality of life for patients.

scholarly journals Regulation of Adult Neurogenesis in Mammalian Brain

2020 ◽  
Vol 21 (14) ◽  
pp. 4869 ◽  
Author(s):  
Maria Victoria Niklison-Chirou ◽  
Massimiliano Agostini ◽  
Ivano Amelio ◽  
Gerry Melino
Keyword(s):  
Transcription Factors ◽  
Adult Neurogenesis ◽  
Metabolic Pathways ◽  
Metabolic Regulation ◽  
Adult Brain ◽  
Mammalian Brain ◽  
P53 Family ◽  
Intrinsic Factors ◽  
The Past ◽  
Non Coding Rnas

Adult neurogenesis is a multistage process by which neurons are generated and integrated into existing neuronal circuits. In the adult brain, neurogenesis is mainly localized in two specialized niches, the subgranular zone (SGZ) of the dentate gyrus and the subventricular zone (SVZ) adjacent to the lateral ventricles. Neurogenesis plays a fundamental role in postnatal brain, where it is required for neuronal plasticity. Moreover, perturbation of adult neurogenesis contributes to several human diseases, including cognitive impairment and neurodegenerative diseases. The interplay between extrinsic and intrinsic factors is fundamental in regulating neurogenesis. Over the past decades, several studies on intrinsic pathways, including transcription factors, have highlighted their fundamental role in regulating every stage of neurogenesis. However, it is likely that transcriptional regulation is part of a more sophisticated regulatory network, which includes epigenetic modifications, non-coding RNAs and metabolic pathways. Here, we review recent findings that advance our knowledge in epigenetic, transcriptional and metabolic regulation of adult neurogenesis in the SGZ of the hippocampus, with a special attention to the p53-family of transcription factors.

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