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Adult neurogenesis in humans- common and unique traits in mammals.

Ernst A, Frisén J - PLoS Biol. (2015)

Bottom Line: Data on the extent and dynamics of adult neurogenesis in adult humans are starting to emerge, and there are clear similarities and differences compared to other mammals.Why do these differences arise?And what do they mean?

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden; Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany.

ABSTRACT
New neurons are continuously generated in specific regions in the adult brain. Studies in rodents have demonstrated that adult-born neurons have specific functional features and mediate neural plasticity. Data on the extent and dynamics of adult neurogenesis in adult humans are starting to emerge, and there are clear similarities and differences compared to other mammals. Why do these differences arise? And what do they mean?

No MeSH data available.


Proportional OB (A), hippocampal (B), and striatal volumes (C).Species are grouped according to major phylogenetic classes varying in phylogenetic distance from humans: nonprimates first (e.g., shrews, tenrecs, hedgehogs), then Strepsirrhine (e.g., lemur), Tarsier, Platyirrhine (e.g., New World monkey), Cercopithecine (e.g., baboon, macaque), Hylobate (e.g., gibbon), Nonhuman hominidae (e.g., chimpanzee, gorilla). The proportional volume of the OBs decreases across primate species. Humans display the most pronounced reduction in OB volume. Hippocampal volumes appear to maintain their proportions across species, whereas proportional striatal volumes increase with evolution. The proportions of regional brain volumes are calculated as proportions of medulla volumes, because no grade shifts in the relationship between medulla volume and body size are observed [34]. Volumetric measurements are from Stephan et al. [48].
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pbio.1002045.g002: Proportional OB (A), hippocampal (B), and striatal volumes (C).Species are grouped according to major phylogenetic classes varying in phylogenetic distance from humans: nonprimates first (e.g., shrews, tenrecs, hedgehogs), then Strepsirrhine (e.g., lemur), Tarsier, Platyirrhine (e.g., New World monkey), Cercopithecine (e.g., baboon, macaque), Hylobate (e.g., gibbon), Nonhuman hominidae (e.g., chimpanzee, gorilla). The proportional volume of the OBs decreases across primate species. Humans display the most pronounced reduction in OB volume. Hippocampal volumes appear to maintain their proportions across species, whereas proportional striatal volumes increase with evolution. The proportions of regional brain volumes are calculated as proportions of medulla volumes, because no grade shifts in the relationship between medulla volume and body size are observed [34]. Volumetric measurements are from Stephan et al. [48].

Mentions: What could explain the divergent patterns of adult neurogenesis in distinct regions of the mammalian brain? New neurons, as well as changes in the proportion and organization of particular brain structures, offer a selective advantage to individuals by giving them the cognitive adaptability necessary to conquer diverse ecological niches [33]. In general, increasing the size of a brain region enhances the associated functional domains [34]. A decrease in olfactory abilities with evolution is well documented and linked to a reduced dependence on olfaction. This functional regression is associated with a decrease in OB volume across phylogenetic groups, and most extremely in humans (Fig. 2A) [34]. In contrast, relative hippocampal volumes remain rather constant across species, which supports the notion that hippocampal memory seems to be necessary for the success of an organism, regardless of its environmental niche (Fig. 2B) [34]. The neostriatum, comprising the caudate nucleus and the putamen, is a phylogenetically new component of the brain. Over the course of evolution, the striatum enlarged in parallel with the cerebral cortex; it is particularly well developed in higher mammals, including humans (Fig. 2C). This proportional increase of the striatum with evolution implies a heavier reliance on movement coordination, cognition, and emotions.


Adult neurogenesis in humans- common and unique traits in mammals.

Ernst A, Frisén J - PLoS Biol. (2015)

Proportional OB (A), hippocampal (B), and striatal volumes (C).Species are grouped according to major phylogenetic classes varying in phylogenetic distance from humans: nonprimates first (e.g., shrews, tenrecs, hedgehogs), then Strepsirrhine (e.g., lemur), Tarsier, Platyirrhine (e.g., New World monkey), Cercopithecine (e.g., baboon, macaque), Hylobate (e.g., gibbon), Nonhuman hominidae (e.g., chimpanzee, gorilla). The proportional volume of the OBs decreases across primate species. Humans display the most pronounced reduction in OB volume. Hippocampal volumes appear to maintain their proportions across species, whereas proportional striatal volumes increase with evolution. The proportions of regional brain volumes are calculated as proportions of medulla volumes, because no grade shifts in the relationship between medulla volume and body size are observed [34]. Volumetric measurements are from Stephan et al. [48].
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4306487&req=5

pbio.1002045.g002: Proportional OB (A), hippocampal (B), and striatal volumes (C).Species are grouped according to major phylogenetic classes varying in phylogenetic distance from humans: nonprimates first (e.g., shrews, tenrecs, hedgehogs), then Strepsirrhine (e.g., lemur), Tarsier, Platyirrhine (e.g., New World monkey), Cercopithecine (e.g., baboon, macaque), Hylobate (e.g., gibbon), Nonhuman hominidae (e.g., chimpanzee, gorilla). The proportional volume of the OBs decreases across primate species. Humans display the most pronounced reduction in OB volume. Hippocampal volumes appear to maintain their proportions across species, whereas proportional striatal volumes increase with evolution. The proportions of regional brain volumes are calculated as proportions of medulla volumes, because no grade shifts in the relationship between medulla volume and body size are observed [34]. Volumetric measurements are from Stephan et al. [48].
Mentions: What could explain the divergent patterns of adult neurogenesis in distinct regions of the mammalian brain? New neurons, as well as changes in the proportion and organization of particular brain structures, offer a selective advantage to individuals by giving them the cognitive adaptability necessary to conquer diverse ecological niches [33]. In general, increasing the size of a brain region enhances the associated functional domains [34]. A decrease in olfactory abilities with evolution is well documented and linked to a reduced dependence on olfaction. This functional regression is associated with a decrease in OB volume across phylogenetic groups, and most extremely in humans (Fig. 2A) [34]. In contrast, relative hippocampal volumes remain rather constant across species, which supports the notion that hippocampal memory seems to be necessary for the success of an organism, regardless of its environmental niche (Fig. 2B) [34]. The neostriatum, comprising the caudate nucleus and the putamen, is a phylogenetically new component of the brain. Over the course of evolution, the striatum enlarged in parallel with the cerebral cortex; it is particularly well developed in higher mammals, including humans (Fig. 2C). This proportional increase of the striatum with evolution implies a heavier reliance on movement coordination, cognition, and emotions.

Bottom Line: Data on the extent and dynamics of adult neurogenesis in adult humans are starting to emerge, and there are clear similarities and differences compared to other mammals.Why do these differences arise?And what do they mean?

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden; Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany.

ABSTRACT
New neurons are continuously generated in specific regions in the adult brain. Studies in rodents have demonstrated that adult-born neurons have specific functional features and mediate neural plasticity. Data on the extent and dynamics of adult neurogenesis in adult humans are starting to emerge, and there are clear similarities and differences compared to other mammals. Why do these differences arise? And what do they mean?

No MeSH data available.