Search results for "doublecortin"
showing 10 items of 46 documents
Positive Controls in Adults and Children Support That Very Few, If Any, New Neurons Are Born in the Adult Human Hippocampus.
2020
Adult hippocampal neurogenesis was originally discovered in rodents. Subsequent studies identified the adult neural stem cells and found important links between adult neurogenesis and plasticity, behavior, and disease. However, whether new neurons are produced in the human dentate gyrus (DG) during healthy aging is still debated. We and others readily observe proliferating neural progenitors in the infant hippocampus near immature cells expressing doublecortin (DCX), but the number of such cells decreases in children and few, if any, are present in adults. Recent investigations using dual antigen retrieval find many cells stained by DCX antibodies in adult human DG. This has been interprete…
Neurochemical Phenotype of Reelin Immunoreactive Cells in the Piriform Cortex Layer II
2016
Reelin, a glycoprotein expressed by Cajal-Retzius neurons throughout the marginal layer of developing neocortex, has been extensively shown to play an important role during brain development, guiding neuronal migration and detachment from radial glia. During the adult life, however, many studies have associated Reelin expression to enhanced neuronal plasticity. Although its mechanism of action in the adult brain remains mostly unknown, Reelin is expressed mainly by a subset of mature interneurons. Here, we confirm the described phenotype of this subpopulation in the adult neocortex. We show that these mature interneurons, although being in close proximity, lack polysialylated neural cell ad…
Amyotrophic lateral sclerosis modifies progenitor neural proliferation in adult classic neurogenic brain niches.
2017
Background Adult neurogenesis persists through life at least in classic neurogenic niches. Neurogenesis has been previously described as reduced in neurodegenerative diseases. There is not much knowledge about is adult neurogenesis is or not modified in amyotrophy lateral sclerosis (ALS). All previous publications has studied the ALS SOD1 (superoxide dismutase) transgenic mouse model. The purpose of this study is to examine the process of adult neurogenesis in classic niches (subventricular zone [SVZ] and subgranular zone [SGZ] of the dentate gyrus) in patients with amyotrophic lateral sclerosis (ALS), both with (ALS-FTD) and without associated frontotemporal dementia (FTD). Methods We stud…
Neural stem cells in the adult olfactory bulb core generate mature neurons in vivo.
2021
17 páginas, 7 figuras.
Hypocellularity in the murine model for Down Syndrome Ts65Dn is not affected by adult neurogenesis
2016
Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity …
Characterization and isolation of immature neurons of the adult mouse piriform cortex
2015
Physiological studies indicate that the piriform or primary olfactory cortex of adult mammals exhibits a high degree of synaptic plasticity. Interestingly, a subpopulation of cells in the layer II of the adult piriform cortex expresses neurodevelopmental markers, such as the polysialylated form of neural cell adhesion molecule (PSA-NCAM) or doublecortin (DCX). This study analyzes the nature, origin, and potential function of these poorly understood cells in mice. As previously described in rats, most of the PSA-NCAM expressing cells in layer II could be morphologically classified as tangled cells and only a small proportion of larger cells could be considered semilunar-pyramidal transitiona…
Phylogenetic variation in cortical layer II immature neuron reservoir of mammals
2020
The adult mammalian brain is mainly composed of mature neurons. A limited amount of stem cell-driven neurogenesis persists in postnatal life and is reduced in large-brained species. Another source of immature neurons in adult brains is cortical layer II. These cortical immature neurons (cINs) retain developmentally undifferentiated states in adulthood, though they are generated before birth. Here, the occurrence, distribution and cellular features of cINs were systematically studied in 12 diverse mammalian species spanning from small-lissencephalic to large-gyrencephalic brains. In spite of well-preserved morphological and molecular features, the distribution of cINs was highly heterogeneou…
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…
PSA-NCAM expression in the human prefrontal cortex.
2006
The prefrontal cortex (PFC) of adult rodents is capable of undergoing neuronal remodeling and neuroimaging studies in humans have revealed that the structure of this region also appears affected in different psychiatric disorders. However, the cellular mechanisms underlying this plasticity are still unclear. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) may mediate these structural changes through its anti-adhesive properties. PSA-NCAM participates in neurite outgrowth and synaptogenesis and changes in its expression occur parallel to neuronal remodeling in certain regions of the adult brain. PSA-NCAM is expressed in the hippocampus and temporal cortex of adult hum…
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…