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LaDage LD. Broadening the functional and evolutionary understanding of postnatal neurogenesis using reptilian models. ACTA ACUST UNITED AC 2020; 223:223/15/jeb210542. [PMID: 32788272 DOI: 10.1242/jeb.210542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The 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.
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Affiliation(s)
- Lara D LaDage
- Division of Mathematics and Natural Sciences, Penn State Altoona, 3000 Ivyside Dr., Altoona, PA 16601, USA
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LaDage LD, Roth TC, Downs CJ, Sinervo B, Pravosudov VV. Increased Testosterone Decreases Medial Cortical Volume and Neurogenesis in Territorial Side-Blotched Lizards ( Uta stansburiana). Front Neurosci 2017; 11:97. [PMID: 28298883 PMCID: PMC5331184 DOI: 10.3389/fnins.2017.00097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/14/2017] [Indexed: 01/18/2023] Open
Abstract
Variation in an animal's spatial environment can induce variation in the hippocampus, an area of the brain involved in spatial cognitive processing. Specifically, increased spatial area use is correlated with increased hippocampal attributes, such as volume and neurogenesis. In the side-blotched lizard (Uta stansburiana), males demonstrate alternative reproductive tactics and are either territorial—defending large, clearly defined spatial boundaries—or non-territorial—traversing home ranges that are smaller than the territorial males' territories. Our previous work demonstrated cortical volume (reptilian hippocampal homolog) correlates with these spatial niches. We found that territorial holders have larger medial cortices than non-territory holders, yet these differences in the neural architecture demonstrated some degree of plasticity as well. Although we have demonstrated a link among territoriality, spatial use, and brain plasticity, the mechanisms that underlie this relationship are unclear. Previous studies found that higher testosterone levels can induce increased use of the spatial area and can cause an upregulation in hippocampal attributes. Thus, testosterone may be the mechanistic link between spatial area use and the brain. What remains unclear, however, is if testosterone can affect the cortices independent of spatial experiences and whether testosterone differentially interacts with territorial status to produce the resultant cortical phenotype. In this study, we compared neurogenesis as measured by the total number of doublecortin-positive cells and cortical volume between territorial and non-territorial males supplemented with testosterone. We found no significant differences in the number of doublecortin-positive cells or cortical volume among control territorial, control non-territorial, and testosterone-supplemented non-territorial males, while testosterone-supplemented territorial males had smaller medial cortices containing fewer doublecortin-positive cells. These results demonstrate that testosterone can modulate medial cortical attributes outside of differential spatial processing experiences but that territorial males appear to be more sensitive to alterations in testosterone levels compared with non-territorial males.
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Affiliation(s)
- Lara D LaDage
- Division of Mathematics and Natural Sciences, Penn State University Altoona Altoona, PA, USA
| | - Timothy C Roth
- Department of Psychology, Franklin and Marshall College Lancaster, PA, USA
| | | | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
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Paredes MF, Sorrells SF, Garcia-Verdugo JM, Alvarez-Buylla A. Brain size and limits to adult neurogenesis. J Comp Neurol 2015; 524:646-64. [PMID: 26417888 DOI: 10.1002/cne.23896] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 08/28/2015] [Accepted: 09/08/2015] [Indexed: 12/31/2022]
Abstract
The walls of the cerebral ventricles in the developing embryo harbor the primary neural stem cells from which most neurons and glia derive. In many vertebrates, neurogenesis continues postnatally and into adulthood in this region. Adult neurogenesis at the ventricle has been most extensively studied in organisms with small brains, such as reptiles, birds, and rodents. In reptiles and birds, these progenitor cells give rise to young neurons that migrate into many regions of the forebrain. Neurogenesis in adult rodents is also relatively widespread along the lateral ventricles, but migration is largely restricted to the rostral migratory stream into the olfactory bulb. Recent work indicates that the wall of the lateral ventricle is highly regionalized, with progenitor cells giving rise to different types of neurons depending on their location. In species with larger brains, young neurons born in these spatially specified domains become dramatically separated from potential final destinations. Here we hypothesize that the increase in size and topographical complexity (e.g., intervening white matter tracts) in larger brains may severely limit the long-term contribution of new neurons born close to, or in, the ventricular wall. We compare the process of adult neuronal birth, migration, and integration across species with different brain sizes, and discuss how early regional specification of progenitor cells may interact with brain size and affect where and when new neurons are added.
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Affiliation(s)
- Mercedes F Paredes
- Department of Neurological Surgery, University of California, San Francisco, CA, 94143, USA
| | - Shawn F Sorrells
- Department of Neurological Surgery, University of California, San Francisco, CA, 94143, USA.,University of California, San Francisco, CA, 94143, USA
| | - Jose M Garcia-Verdugo
- Laboratory of Comparative Neurobiology, Instituto Cavanilles, Universidad de Valencia, CIBERNED, 46980 Valencia, Spain
| | - Arturo Alvarez-Buylla
- Department of Neurological Surgery and The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, 94143, USA
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Clinton BK, Cunningham CL, Kriegstein AR, Noctor SC, Martínez-Cerdeño V. Radial glia in the proliferative ventricular zone of the embryonic and adult turtle, Trachemys scripta elegans. NEUROGENESIS 2014; 1:e970905. [PMID: 27504470 PMCID: PMC4973586 DOI: 10.4161/23262125.2014.970905] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/02/2014] [Accepted: 09/26/2014] [Indexed: 11/19/2022]
Abstract
To better understand the role of radial glial (RG) cells in the evolution of the mammalian cerebral cortex, we investigated the role of RG cells in the dorsal cortex and dorsal ventricular ridge of the turtle, Trachemys scripta elegans. Unlike mammals, the glial architecture of adult reptile consists mainly of ependymoradial glia, which share features with mammalian RG cells, and which may contribute to neurogenesis that continues throughout the lifespan of the turtle. To evaluate the morphology and proliferative capacity of ependymoradial glia (here referred to as RG cells) in the dorsal cortex of embryonic and adult turtle, we adapted the cortical electroporation technique, commonly used in rodents, to the turtle telencephalon. Here, we demonstrate the morphological and functional characteristics of RG cells in the developing turtle dorsal cortex. We show that cell division occurs both at the ventricle and away from the ventricle, that RG cells undergo division at the ventricle during neurogenic stages of development, and that mitotic Tbr2+ precursor cells, a hallmark of the mammalian SVZ, are present in the turtle cortex. In the adult turtle, we show that RG cells encompass a morphologically heterogeneous population, particularly in the subpallium where proliferation is most prevalent. One RG subtype is similar to RG cells in the developing mammalian cortex, while 2 other RG subtypes appear to be distinct from those seen in mammal. We propose that the different subtypes of RG cells in the adult turtle perform distinct functions.
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Affiliation(s)
- Brian K Clinton
- Department of Psychiatry; Columbia University Medical Center ; New York, NY USA
| | | | - Arnold R Kriegstein
- Department of Neurology; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research; and Neuroscience Graduate Program; University of California at San Francisco ; San Francisco, CA USA
| | - Stephen C Noctor
- Department of Psychiatry and Behavioral Sciences; University of California at Davis; Sacramento, CA USA; MIND Institute; University of California at Davis; Sacramento, CA USA
| | - Verónica Martínez-Cerdeño
- MIND Institute; University of California at Davis; Sacramento, CA USA; Institute for Pediatric Regenerative Medicine; University of California at Davis / Shriners Hospitals; Sacramento, CA USA; and Medical Pathology and Laboratory Medicine; University of California at Davis; Sacramento, CA USA
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Zhang G, Vidal Pizarro I, Swain GP, Kang SH, Selzer ME. Neurogenesis in the lamprey central nervous system following spinal cord transection. J Comp Neurol 2014; 522:1316-32. [PMID: 24151158 DOI: 10.1002/cne.23485] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 10/07/2013] [Accepted: 10/08/2013] [Indexed: 12/23/2022]
Abstract
After spinal cord transection, lampreys recover functionally and axons regenerate. It is not known whether this is accompanied by neurogenesis. Previous studies suggested a baseline level of nonneuronal cell proliferation in the spinal cord and rhombencephalon (where most supraspinal projecting neurons are located). To determine whether cell proliferation increases after injury and whether this includes neurogenesis, larval lampreys were spinally transected and injected with 5-bromo-2&prime-deoxyuridine (BrdU) at 0-3 weeks posttransection. Labeled cells were counted in the lesion site, within 0.5 mm rostral and caudal to the lesion, and in the rhombencephalon. One group of animals was processed in the winter and a second group was processed in the summer. The number of labeled cells was greater in winter than in summer. The lesion site had the most BrdU labeling at all times, correlating with an increase in the number of cells. In the adjacent spinal cord, the percentage of BrdU labeling was higher in the ependymal than in nonependymal regions. This was also true in the rhombencephalon but only in summer. In winter, BrdU labeling was seen primarily in the subventricular and peripheral zones. Some BrdU-labeled cells were also double labeled by antibodies to glial-specific (antikeratin) as well as neuron-specific (anti-Hu) antigens, indicating that both gliogenesis and neurogenesis occurred after spinal cord transection. However, the new neurons were restricted to the ependymal zone, were never labeled by antineurofilament antibodies, and never migrated away from the ependyma even at 5 weeks after BrdU injection. They would appear to be cerebrospinal fluid-contacting neurons.
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Affiliation(s)
- Guixin Zhang
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, Penhnsylvania, 19140; Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, 19104
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Quintana-Urzainqui I, Rodríguez-Moldes I, Mazan S, Candal E. Tangential migratory pathways of subpallial origin in the embryonic telencephalon of sharks: evolutionary implications. Brain Struct Funct 2014; 220:2905-26. [PMID: 25079345 DOI: 10.1007/s00429-014-0834-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 06/24/2014] [Indexed: 01/18/2023]
Abstract
Tangential neuronal migration occurs along different axes from the axis demarcated by radial glia and it is thought to have evolved as a mechanism to increase the diversity of cell types in brain areas, which in turn resulted in increased complexity of functional networks. In the telencephalon of amniotes, different embryonic tangential pathways have been characterized. However, little is known about the exact routes of migrations in basal vertebrates. Cartilaginous fishes occupy a key phylogenetic position to assess the ancestral condition of vertebrate brain organization. In order to identify putative subpallial-derived tangential migratory pathways in the telencephalon of sharks, we performed a detailed analysis of the distribution pattern of GAD and Dlx2, two reliable markers of tangentially migrating interneurons of subpallial origin in the developing forebrain. We propose the existence of five tangential routes directed toward different telencephalic regions. We conclude that four of the five routes might have emerged in the common ancestor of jawed vertebrates. We have paid special attention to the characterization of the proposed migratory pathway directed towards the olfactory bulbs. Our results suggest that it may be equivalent to the "rostral migratory stream" of mammals and led us to propose a hypothesis about its evolution. The analysis of the final destinations of two other streams allowed us to identify the putative dorsal and medial pallium of sharks, the regions from which the neocortex and hippocampus might have, respectively, evolved. Derived features were also reported and served to explain some distinctive traits in the morphology of the telencephalon of cartilaginous fishes.
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Affiliation(s)
- Idoia Quintana-Urzainqui
- Departamento de Biología Celular y Ecología, Edificio CIBUS, Campus Vida, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
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Trujillo-Cenóz O, Marichal N, Rehermann MI, Russo RE. The inner lining of the reptilian brain: A heterogeneous cellular mosaic. Glia 2013; 62:300-16. [DOI: 10.1002/glia.22607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 11/05/2013] [Accepted: 11/13/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Omar Trujillo-Cenóz
- Neurofisiología Celular y Molecular; Instituto de Investigaciones Biológicas Clemente Estable; Avenida Italia 3318 CP11600 Montevideo Uruguay
| | - Nicolás Marichal
- Neurofisiología Celular y Molecular; Instituto de Investigaciones Biológicas Clemente Estable; Avenida Italia 3318 CP11600 Montevideo Uruguay
| | - María Inés Rehermann
- Neurofisiología Celular y Molecular; Instituto de Investigaciones Biológicas Clemente Estable; Avenida Italia 3318 CP11600 Montevideo Uruguay
| | - Raúl E. Russo
- Neurofisiología Celular y Molecular; Instituto de Investigaciones Biológicas Clemente Estable; Avenida Italia 3318 CP11600 Montevideo Uruguay
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Srivastava UC, Sakal ID, Maurya RC. Differences Between Dendritic Spines of Neurons of Different Regions of the Cerebral Cortex of the Garden Lizard, C. versicolor (Daudin). ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s40011-012-0049-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Varea E, Belles M, Vidueira S, Blasco-Ibáñez JM, Crespo C, Pastor AM, Nacher J. PSA-NCAM is Expressed in Immature, but not Recently Generated, Neurons in the Adult Cat Cerebral Cortex Layer II. Front Neurosci 2011; 5:17. [PMID: 21415912 PMCID: PMC3042688 DOI: 10.3389/fnins.2011.00017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Accepted: 01/31/2011] [Indexed: 12/17/2022] Open
Abstract
Neuronal production persists during adulthood in the dentate gyrus and the olfactory bulb, where substantial numbers of immature neurons can be found. These cells can also be found in the paleocortex layer II of adult rodents, but in this case most of them have been generated during embryogenesis. Recent reports have described the presence of similar cells, with a wider distribution, in the cerebral cortex of adult cats and primates and have suggested that they may develop into interneurons. The objective of this study is to verify this hypothesis and to explore the origin of these immature neurons in adult cats. We have analyzed their distribution using immunohistochemical analysis of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) and their phenotype using markers of mature neurons and different interneuronal populations. Additionally, we have explored the origin of these cells administering 5′bromodeoxyuridine (5′BrdU) during adulthood. Immature neurons were widely dispersed in the cerebral cortex layers II and upper III, being specially abundant in the piriform and entorhinal cortices, in the ventral portions of the frontal and temporoparietal lobes, but relatively scarce in dorsal regions, such as the primary visual areas. Only a small fraction of PSA-NCAM expressing cells in layer II expressed the mature neuronal marker NeuN and virtually none of them expressed calcium binding proteins or neuropeptides. By contrast, most, if not all of these cells expressed the transcription factor Tbr-1, specifically expressed by pallium-derived principal neurons, but not CAMKII, a marker of mature excitatory neurons. Absence of PSA-NCAM/5′BrdU colocalization suggests that, as in rats, these cells were not generated during adulthood. Together, these results indicate that immature neurons in the adult cat cerebral cortex layer II are not recently generated and that they may differentiate into principal neurons.
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Affiliation(s)
- Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Department of Cell Biology, Universitat de València València, Spain
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Koutsoudaki PN, Skripuletz T, Gudi V, Moharregh-Khiabani D, Hildebrandt H, Trebst C, Stangel M. Demyelination of the hippocampus is prominent in the cuprizone model. Neurosci Lett 2009; 451:83-8. [DOI: 10.1016/j.neulet.2008.11.058] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 11/24/2008] [Accepted: 11/25/2008] [Indexed: 01/27/2023]
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11
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Sampedro C, Font E, Desfilis E. Size variation and cell proliferation in chemosensory brain areas of a lizard (Podarcis hispanica): effects of sex and season. Eur J Neurosci 2008; 28:87-98. [PMID: 18662337 DOI: 10.1111/j.1460-9568.2008.06287.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many lizards rely on chemoreception for crucial aspects of their biology, including exploration, prey and predator detection, and intraspecific communication. Here we investigate sex and seasonal variation in size and proliferative activity in chemosensory areas of the lizard brain. We captured adult Iberian wall lizards (Podarcis hispanica) of either sex in the breeding (April) and non-breeding (November) season, injected them with 5-bromo-2'-deoxyuridine (BrdU) and killed them 3 weeks later. We removed the brains, measured the length of the olfactory bulbs, and counted BrdU-labelled cells in the main and accessory olfactory bulbs (MOB, AOB), lateral cortex (LC) and nucleus sphericus (NS). Our results show that, relative to body size, males have larger MOBs and AOBs than females; however, relative to brain size, males have larger AOBs, but not larger MOBs than females. Additionally, males produce more new cells than females in the olfactory bulbs, LC and NS. We failed to detect significant seasonal changes or sex x season interaction in size or proliferative activity in these areas. Sex differences in the addition of newly generated cells--mainly neurons--may be partly responsible for the size differences in chemosensory brain areas. The presence of sexual dimorphism in AOB is expected given the available behavioural evidence, which suggests that males of P. hispanica are more responsive than females to socially relevant chemical stimuli. This is the first demonstration of sexual dimorphism in size and proliferative activity in chemosensory areas of a non-mammalian species.
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Affiliation(s)
- Carlos Sampedro
- Unidad de Etología, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universidad de Valencia, Paterna, Spain.
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Luzzati F, Bonfanti L, Fasolo A, Peretto P. DCX and PSA-NCAM expression identifies a population of neurons preferentially distributed in associative areas of different pallial derivatives and vertebrate species. ACTA ACUST UNITED AC 2008; 19:1028-41. [PMID: 18832334 DOI: 10.1093/cercor/bhn145] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
In adult rodents, doublecortin (DCX) and polysialylated neural cell adhesion molecule (PSA-NCAM) expression is mostly restricted to newly generated neurons. These molecules have also been described in prenatally generated cells of the piriform cortex and, to a lesser extent, neocortex (NC) of the rat. In addition, PSA-NCAM+ cells have been identified in several telencephalic regions of the lizard. Here, through immunohistochemistry and 3-dimensional reconstruction, we have investigated distribution, morphology, and phenotype of DCX/PSA-NCAM-expressing cells in the pallium of different mammals and in lizard. In all species, a population of nonnewly-generated pallial DCX+/PSA-NCAM+ cells shows common morphological and phenotypic characteristics, including expression of Tbr-1, a transcription factor expressed in pallial projection neurons, and preferential distribution in associative areas. In the guinea pig and rabbit, DCX+/PSA-NCAM+ elements are also abundant in the NC, particularly in areas implicated in nonspatial learning and memory networks. In reptiles, DCX+/PSA-NCAM+ cells are located in the lateral and medial cortex and dorsal ventricular ridge but not in the dorsal cortex. These data support the fact that coexpression of DCX+/PSA-NCAM+/Tbr-1+ in the adult brain identifies evolutionary conserved cell populations shared by different pallial derivatives including the mammalian NC.
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Affiliation(s)
- Federico Luzzati
- Department of Animal and Human Biology, University of Turin, Via Accademia Albertina 13, 10153 Turin, Italy.
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Bulloch K, Miller MM, Gal-Toth J, Milner TA, Gottfried-Blackmore A, Waters EM, Kaunzner UW, Liu K, Lindquist R, Nussenzweig MC, Steinman RM, McEwen BS. CD11c/EYFP transgene illuminates a discrete network of dendritic cells within the embryonic, neonatal, adult, and injured mouse brain. J Comp Neurol 2008; 508:687-710. [PMID: 18386786 DOI: 10.1002/cne.21668] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The CD11c enhanced yellow fluorescent protein (EYFP) transgenic mouse was constructed to identify dendritic cells in the periphery (Lindquist et al. [2004] Nat. Immunol. 5:1243-1250). In this study, we used this mouse to characterize dendritic cells within the CNS. Our anatomic results showed discrete populations of EYFP(+) brain dendritic cells (EYFP(+) bDC) that colocalized with a small fraction of microglia immunoreactive for Mac-1, Iba-1, CD45, and F4/80 but not for NeuN, Dcx, NG2 proteoglycan, or GFAP. EYFP(+) bDC, isolated by fluorescent activated cell sorting (FACS), expressed mRNA for the Itgax (CD11c) gene, whereas FACS anlaysis of EYFP(+) bDC cultures revealed the presence of CD11c protein. Light microscopy studies revealed that EYFP(+) bDC were present in the embryonic CNS when the blood-brain barrier is formed and postnatally when brain cells are amenable to culturing. In adult male mice, EYFP(+) bDC distribution was prominent within regions of the CNS that 1) are subject to structural plasticity and neurogenesis, 2) receive sensory and humoral input from the external environment, and 3) lack a blood-brain barrier. Ultrastructural analysis of EYFP(+) bDC in adult neurogenic niches showed their proximity to developing neurons and a morphology characteristic of immune/microglia cells. Kainic acid-induced seizures revealed that EYFP(+) bDC responded to damage of the hippocampus and displayed morphologies similar to those described for seizure-activated EGFP(+) microglia in the hippocampus of cfms (CSF-1R) EGFP mice. Collectively, these findings suggest a new member of the dendritic cell family residing among the heterogeneous microglia population.
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Affiliation(s)
- Karen Bulloch
- Laboratory of Cellular Physiology and Immunology, The Rockefeller University, New York, New York 10065, USA.
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Kaslin J, Ganz J, Brand M. Proliferation, neurogenesis and regeneration in the non-mammalian vertebrate brain. Philos Trans R Soc Lond B Biol Sci 2008; 363:101-22. [PMID: 17282988 PMCID: PMC2605489 DOI: 10.1098/rstb.2006.2015] [Citation(s) in RCA: 254] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
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.
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Affiliation(s)
| | | | - Michael Brand
- Biotechnology Centre and Centre for Regenerative Therapies Dresden, Dresden University of TechnologyTatzberg 47-51, 01307 Dresden, Germany
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Meyer WN, Keifer J, Korzan WJ, Summers CH. Social stress and corticosterone regionally upregulate limbic N-methyl-d-aspartatereceptor (NR) subunit type NR2A and NR2B in the lizard anolis carolinensis. Neuroscience 2004; 128:675-84. [PMID: 15464276 DOI: 10.1016/j.neuroscience.2004.06.084] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2004] [Indexed: 11/29/2022]
Abstract
Social aggression in the lizard Anolis carolinensis produces dominant and subordinate relationships while elevating corticosterone levels and monoaminergic transmitter activity in hippocampus (medial and mediodorsal cortex). Adaptive social behavior for dominant and subordinate male A. carolinensis is learned during aggressive interaction and therefore was hypothesized to involve hippocampus and regulation of N-methyl-d-aspartate (NMDA) receptors. To test the effects of social stress and corticosterone on NMDA receptor subunits (NR), male lizards were either paired or given two injections of corticosterone 1 day apart. Paired males were allowed to form dominant-subordinate relationships and were killed 1 day later. Groups included isolated controls, dominant males, subordinate males and males injected with corticosterone. Brains were processed for glutamate receptor subunit immunohistochemistry and fluorescence was analyzed by image analysis for NR(2A) and NR(2B) in the small and large cell divisions of the medial and mediodorsal cortex. In the small granule cell division there were no significant differences in NR(2A) or NR(2B) immunoreactivity among all groups. In contrast, there was a significant upregulation of NR(2A) and NR(2B) subunits in the large pyramidal cell division in all three experimental groups as compared with controls. The results revealed significantly increased NR(2A) and NR(2B) subunits in behaving animals, whereas animals simply injected with corticosterone showed less of an effect, although they were significantly increased over control. Upregulation of NR(2) subunits occurs during stressful social interactions and is likely to be regulated in part by glucocorticoids. The data also suggest that learning social roles during stressful aggressive interactions may involve NMDA receptor-mediated mechanisms.
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Affiliation(s)
- W N Meyer
- Department of Biology, University of South Dakota, 414 East Clark Street, Vermillion, SD 57069, USA
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Nacher J, Soriano S, Varea E, Molowny A, Ponsoda X, Lopez-Garcia C. CRMP-4 expression in the adult cerebral cortex and other telencephalic areas of the lizard Podarcis hispanica. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2002; 139:285-94. [PMID: 12480143 DOI: 10.1016/s0165-3806(02)00589-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The control of neuritogenesis is crucial for the development, maturation and regeneration of the nervous system. The collapsin response-mediated protein 4 (CRMP-4) is a member of a family of proteins that are involved in neuronal differentiation and axonal outgrowth. In rodents, this protein is expressed in recently generated neurons such as some granule neurons of the dentate gyrus, as well as in certain differentiated neurons undergoing neurite outgrowth or synaptogenesis during adulthood. Since CRMP-4 protein appears to be highly conserved throughout the evolutionary scale, we have used immunocytochemistry to study its distribution in the lizard cerebral cortex. We have found pronounced CRMP-4 immunolabeling in certain neurons of the medial cortex, the homologous region to the dentate gyrus, but also in the dorsal and lateral cortices. Double labeling with 5'-BrdU indicated that these medial cortex neurons were recently generated. However, it is also possible that many of these cells were not new but undergoing some kind of plasticity implicating neurite outgrowth. Similar CRMP-4-labeled neurons and processes were observed in subcortical regions as the PDVR and the nucleus sphericus. Our results show for the first time the expression of CRMP-4 in a reptile brain, where it appears to be expressed in regions where adult neurogenesis and/or neurite outgrowth occur.
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Affiliation(s)
- Juan Nacher
- Neurobiologia, Biologia Celular, Facultad de Ciencias Biologicas, Universidad de Valencia, 46100 Burjassot, Valencia, Spain.
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