Search results for "Neurogenesi"

Pharmacological activation of CB2 receptors counteracts the deleterious effect of ethanol on cell proliferation in the main neurogenic zones of the a…

2015

Chronic alcohol exposure reduces endocannabinoid activity and disrupts adult neurogenesis in rodents, which results in structural and functional alterations. Cannabinoid receptor agonists promote adult neural progenitor cell (NPC) proliferation. We evaluated the protective effects of the selective CB1 receptor agonist ACEA, the selective CB2 receptor agonist JWH133 and the fatty-acid amide-hydrolase (FAAH) inhibitor URB597, which enhances endocannabinoid receptor activity, on NPC proliferation in rats with forced consumption of ethanol (10%) or sucrose liquid diets for 2 weeks. We performed immunohistochemical and stereological analyses of cells expressing the mitotic phosphorylation of his…

Direct Reprogramming of Somatic Cells into Induced Neuronal Cells: Where We Are and Where We Want to Go

2014

Direct reprogramming of somatic cells has emerged as a novel strategy to generate neurons, including those of human origin. The method provides enormous potential for studying the mechanisms directing neuronal differentiation, the modeling of neurodegenerative diseases, and the development of potential novel approaches for brain repair. In this chapter, we briefly trace the history of reprogramming, as well as the strategies employed to date for converting different types of somatic cells, including fibroblasts, hepatocytes, astrocytes, and pericytes into induced neuronal cells of different subtype identity. Reprogramming involves particular emphasis on transcriptional and posttranscription…

Occurrence of new neurons in the piriform cortex

2015

In a recent mini-review (Yuan et al., 2015), support is given to the idea that neurons are generated during adulthood in the mammalian piriform cortex (PC), their periventricular origin being also discussed. It is known since long time that a subpopulation of cortical layer II cells in the adult PC of rodents express immature neuronal markers such as polysialylated NCAM (PSA-NCAM; Seki and Arai, 1991; Bonfanti et al., 1992) and doublecortin (DCX; Nacher et al., 2002). These immature neurons have been found in most mammals studied so far, their occurrence being restricted to the paleocortex in rodents (Seki and Arai, 1991; Bonfanti et al., 1992; Nacher et al., 2002), and extended to neocorti…

Physiological Interactions between Microglia and Neural Stem Cells in the Adult Subependymal Niche

2018

Microglia are the prototypical innate immune cells of the central nervous system. They constitute a unique type of tissue-resident mononuclear phagocytes which act as glial cells. Elegant experiments in the last few years have revealed the origin, extraordinary molecular diversity, and phenotypic plasticity of these cells and how their potential relates to both immune and non-immune actions in the normal and diseased brain. Microglial cells originate in the yolk sac and colonize the brain during embryogenesis, playing a role in neural development and later in adult brain function. Neurogenesis continues after birth in discrete areas of the mammalian brain sustained by the postnatal persiste…

Does Adult Neurogenesis Persist in the Human Hippocampus?

2018

Stress-Related Dysfunction of Adult Hippocampal Neurogenesis—An Attempt for Understanding Resilience?

2021

Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events fr…

Criss‐crossing autism spectrum disorder and adult neurogenesis

2021

Autism spectrum disorder (ASD) comprises a group of multifactorial neurodevelopmental disorders primarily characterized by deficits in social interaction and repetitive behavior. Although the onset is typically in early childhood, ASD poses a lifelong challenge for both patients and caretakers. Adult neurogenesis (AN) is the process by which new functional neurons are created from neural stem cells existing in the post-natal brain. The entire event is based on a sequence of cellular processes, such as proliferation, specification of cell fate, maturation, and ultimately, synaptic integration into the existing neural circuits. Hence, AN is implicated in structural and functional brain plasti…

Unique astrocyte ribbon in adult human brain contains neural stem cells but lacks chain migration

2003

The subventricular zone (SVZ) is a principal source of adult neural stem cells in the rodent brain, generating thousands of olfactory bulb neurons every day. If the adult human brain contains a comparable germinal region, this could have considerable implications for future neuroregenerative therapy. Stem cells have been isolated from the human brain, but the identity, organization and function of adult neural stem cells in the human SVZ are unknown. Here we describe a ribbon of SVZ astrocytes lining the lateral ventricles of the adult human brain that proliferate in vivo and behave as multipotent progenitor cells in vitro. This astrocytic ribbon has not been observed in other vertebrates s…

Cells expressing markers of immature neurons in the amygdala of adult humans

2012

The polysialylated form of the neuronal cell adhesion molecule (PSA-NCAM) is expressed by immature neurons in the amygdala of adult mammals, including non-human primates. In a recent report we have also described the presence of PSA-NCAM-expressing cells in the amygdala of adult humans. Although many of these cells have been classified as mature interneurons, some of them lacked mature neuronal markers, suggesting the presence of immature neurons. We have studied, using immunohistochemistry, the existence and distribution of these immature neurons using post mortem material. We have also analysed the presence of proliferating cells and the association between immature neurons and specialise…

Long-term hydrocephalus alters the cytoarchitecture of the adult subventricular zone

2014

Hydrocephalus can develop secondarily to a disturbance in production, flow and/or absorption of cerebrospinal fluid. Experimental models of hydrocephalus, especially subacute and chronic hydrocephalus, are few and limited, and the effects of hydrocephalus on the subventricular zone are unclear. The aim of this study was to analyze the effects of long-term obstructive hydrocephalus on the subventricular zone, which is the neurogenic niche lining the lateral ventricles. We developed a new method to induce hydrocephalus by obstructing the aqueduct of Sylvius in the mouse brain, thus simulating aqueductal stenosis in humans. In 120-day-old rodents (n = 18 per group), the degree of ventricular d…