Neurogenesis

Neurogenesis
BrdU (red), a marker of DNA replication, highlights neurogenesis in the subgranular zone of hippocampal dentate gyrus. Fragment of an illustration from Faiz et al., 2005.[1]

Neurogenesis (birth of neurons) is the process by which neurons are generated from neural stem and progenitor cells. Most active during pre-natal development, neurogenesis is responsible for populating the growing brain with neurons. Recently neurogenesis was shown to continue in several small parts of the brain of mammals: the hippocampus and the subventricular zone. Studies have indicated that hormones, such as testosterone in vertebrates and ecdysone in invertebrates, have an influence on the rate of neurogenesis.

Contents

Occurrence in adults

Doublecortin expression in the rat dentate gyrus, 21st postnatal day. Oomen et al., 2009.[2]

New neurons are continually born throughout adulthood in predominantly two regions of the brain:

Many of the newborn cells die shortly after they are born, but a number of them become functionally integrated into the surrounding brain tissue.

Adult neurogenesis is an example of a long-held scientific theory being overturned. Early neuroanatomists, including Santiago Ramon y Cajal, considered the nervous system fixed and incapable of regeneration. The first evidence of adult mammalian neurogenesis in the cerebral cortex was presented by Joseph Altman in 1962,[3] followed by a demonstration of adult neurogenesis in the dentate gyrus of the hippocampus in 1963.[4] In 1969, Joseph Altman discovered and named the rostral migratory stream as the source of adult generated granule cell neurons in the olfactory bulb.[5] Up until the 1980s, the scientific community ignored these findings despite use of the most direct method of demonstrating cell proliferation in the early studies, i. e. 3H-thymidine autoradiography. By that time, Shirley Bayer [6][7] (and Michael Kaplan) again showed that adult neurogenesis exists in mammals (rats), and Nottebohm showed the same phenomenon in birds[8] sparking renewed interest in the topic. Studies in the 1990s[9][10] finally put research on adult neurogenesis into a mainstream pursuit. Also in the early 1990s hippocampal neurogenesis was demonstrated in non-human primates and humans.[11][12] More recently, neurogenesis in the cerebellum of adult rabbits has also been characterized.[13] Further, some authors (particularly Elizabeth Gould) have suggested that adult neurogenesis may also occur in regions within the brain not generally associated with neurogenesis including the neocortex.[14][15][16] However, others[17] have questioned the scientific evidence of these findings, arguing that the new cells may be of glial origin.

Role in learning

The functional relevance of adult neurogenesis is uncertain,[18] but there is some evidence that hippocampal adult neurogenesis is important for learning and memory.[19] Multiple mechanisms for the relationship between increased neurogenesis and improved cognition have been suggested, including computational theories to demonstrate that new neurons increase memory capacity,[20] reduce interference between memories,[21] or add information about time to memories.[22] Experiments aimed at ablating neurogenesis have proven inconclusive, but several studies have proposed neurogenic-dependence in some types of learning,[23] and others seeing no effect.[24] Studies have demonstrated that the act of learning itself is associated with increased neuronal survival.[25] However, the overall findings that adult neurogenesis is important for any kind of learning are equivocal.

Effects of stress

Adult-born neurons appear to have a role in the regulation of stress. Studies have linked neurogenesis to the beneficial actions of specific antidepressants, suggesting a connection between decreased hippocampal neurogenesis and depression.[26][27] In a subsequent paper, scientists demonstrated that the behavioral benefits of antidepressant administration in mice is reversed when neurogenesis is prevented with x-irradiation techniques.[28] In fact, new-born neurons are more excitable than older neurons due to a differential expression of GABA receptors.[citation needed] A plausible model, therefore, is that these neurons augment the role of the hippocampus in the negative feedback mechanism of the HPA-axis (physiological stress) and perhaps in inhibiting the amygdala (the region of brain responsible for fearful responses to stimuli).[vague] Indeed, suppression of adult neurogenesis can lead to an increased HPA-axis stress response in mildly stressful situations.[29] This is consistent with numerous findings linking stress-relieving activities (learning, exposure to a new yet benign environment, and exercise) to increased levels of neurogenesis, as well as the observation that animals exposed to physiological stress (cortisol) or psychological stress (e.g. isolation) show markedly decreased levels of new-born neurons. Strikingly, the elevation of newborn neurons by antidepressants improves, under chronic stress conditions, the hippocampal control on the stress response (including the activity of the HPA axis and of stress-integrative brain nuclei), then leading to recovery; without newborn neurons, antidepressants are unable to restore the regulation of the stress response and recovery becomes impossible.[30]

Some studies have hypothesized that learning and memory are linked to depression, and that neurogenesis may promote neuroplasticity. One study proposes that mood may be regulated, at a base level, by plasticity, and thus not chemistry. Accordingly, the effects of antidepressant treatment would only be secondary to change in plasticity.[31]

Effects of sleep reduction

One study has linked lack of sleep to a reduction in rodent hippocampal neurogenesis. The proposed mechanism for the observed decrease was increased levels of glucocorticoids. It was shown that two weeks of sleep deprivation acted as a neurogenesis-inhibitor, which was reversed after return of normal sleep and even shifted to a temporary increase in normal cell proliferation.[32] More precisely, when levels of corticosterone are elevated, sleep deprivation inhibits this process. Nonetheless, normal levels of neurogenesis after chronic sleep deprivation return after 2 weeks, with a temporary increase of neurogenesis. (http://www.pnas.org/content/103/50/19170.full)

Possible use in treating Parkinson's disease

Parkinson's disease is a neurodegenerative disorder characterized by a progressive loss of dopaminergic neurons in the nigrostriatal projection. Transplantation of fetal dopaminergic precursor cells has paved the way for the possibility of a cell replacement therapy that could ameliorate clinical symptoms in affected patients.[33] Recent years have provided evidence for the existence of neural stem cells with the potential to produce new neurons, particularly of a dopaminergic phenotype, in the adult mammalian brain.[34][35][36] Experimental depletion of dopamine in rodents decreases precursor cell proliferation in both the subependymal zone and the subgranular zone.[37] Proliferation is restored completely by a selective agonist of D2-like (D2L) receptors.[37] Neural stem cells have been identified in the neurogenic brain regions, where neurogenesis is constitutively ongoing, but also in the non-neurogenic zones, such as the midbrain and the striatum, where neurogenesis is not thought to occur under normal physiological conditions.[33] A detailed understanding of the factors governing adult neural stem cells in vivo may ultimately lead to elegant cell therapies for neurodegenerative disorders such as Parkinson's disease by mobilizing autologous endogenous neural stem cells to replace degenerated neurons.[33]

Role in behavioral sensitization

Reinforcing drugs such as amphetamines and opiates induce behavioral sensitization upon repeated administration by inducing dopaminergic neurogenesis in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc).[38][39][40][41][42] This occurs through activation of dopamine receptors in these areas which produces glutamate release and subsequent elevation of local basic fibroblast growth factor (bFGF) concentrations.[38][39][40][41][42] The consequences of these actions are potentiated reward responses and therefore increased drug cravings and consumption which underlie abuse and addiction. Whether these mechanisms could be exploited for the purpose of enhancing basal hedonic tone is unknown.

Effects of exercise

Scientists have shown that physical activity in the form of voluntary exercise results in an increase in the number of newborn neurons in the hippocampus of aging mice. The same study demonstrates an enhancement in learning of the "runner" (physically active) mice.[43][44] Another research, nonetheless, demonstrated that mice exercising that did not produce beta-endorphin, a mood-elevating hormone, had no change in neurogenesis. Yet, mice that did produce this hormone, along with exercising, exhibited an increase in newborn cells and their rate of survival ( http://www.sfn.org/index.aspx?pagename=brainbriefings_adult_neurogenesis). While the association between exercise-mediated neurogenesis and enhancement of learning remains unclear, this study could have strong implications in the fields of aging and/or [Alzheimer's disease]].

Changes in old age

Neurogenesis is substantially reduced in the hippocampus of aged animals, raising the possibility that it may be linked to age-related declines in hippocampal function. Given that neurogenesis occurs throughout life, it might be expected that the hippocampus would steadily increase in size during adulthood, and that therefore the number of granule cells would be increased in aged animals. However, this is not the case, indicating that proliferation is balanced by cell death. Thus, it is not the addition of new neurons into the hippocampus that seems to be linked to hippocampal functions, but rather the rate of turnover of granule cells.[45].

Alzheimer's disease

Allopregnanolone, a neurosteroid, aids the continued neurogenesis in the brain. Levels of allopregnanolone in the brain decline in old age and Alzheimer's disease.[46] Allopregnanolone has been shown through reversing impairment of neurogenesis to reverse the cognitive deficits in a mouse model of Alzheimer's disease.[47]

Regulation

Many factors may affect the rate of hippocampal neurogenesis. Exercise and an enriched environment have been shown to promote the survival of neurons and the successful integration of newborn cells into the existing hippocampus.,[43][48][49][50] Another factor is central nervous system injury since neurogenesis occurs after cerebral ischemia,[51] epileptic seizures,[52] and bacterial meningitis.[53] On the other hand, conditions such as chronic stress and aging can result in a decreased neuronal proliferation.[54][55][56]

Circulating factors within the blood may reduce neurogenesis. In healthy aging humans, the plasma and cerebrospinal fluid levels of certain chemokines are elevated. In a mouse model, plasma levels of these chemokines correlate with reduced neurogenesis, suggesting that neurogenesis may be modulated by certain global age-dependent systemic changes. These chemokines include CCL11, CCL2 and CCL12, which are highly localized on mouse and human chromosomes, implicating a genetic locus in aging.[57]

Adult neural stem cells

Main article: neural stem cell

Neural stem cells (NSCs) are the self-renewing, multipotent cells that generate the main phenotypes of the nervous system.

Effects of Marijuana

Some studies have shown that use of cannabis results in the growth of new nerve cells in the hippocampus from both embryonic and adult stem cells. In 2005 a clinical study of rats at the University of Saskatchewan showed regeneration of nerve cells in the hippocampus.[58] Studies have shown that a synthetic drug resembling THC, the main psychoactive ingredient in marijuana, provides some protection against brain inflammation, which might result in better memory at an older age. This is due to receptors in the system that can also influence the production of new neurons (http://www.osu.edu/news/newsitem2227) Nonetheless, a study directed at Rutgers University demonstrated how synchronization of action potentials in the hippocampus of rats was altered after THC administration. Lack of synchronization resulted in impaired performance in a standard test of memory. (http://www.physorg.com/news84048508.html) Moreover, contrary to popular belief, animal studies have revealed that marijuana could provoke fits.(http://www.livescience.com/1134-marijuana-impairs-memory.html)

See also

References

  1. ^ Faiz M, Acarin L, Castellano B, Gonzalez B (2005). "Proliferation dynamics of germinative zone cells in the intact and excitotoxically lesioned postnatal rat brain". BMC Neurosci 6: 26. doi:10.1186/1471-2202-6-26. PMC 1087489. PMID 15826306. http://www.biomedcentral.com/1471-2202/6/26. 
  2. ^ Oomen CA, Girardi CE, Cahyadi R, ''et al.'' (2009). Baune, Bernhard. ed. "Opposite effects of early maternal deprivation on neurogenesis in male versus female rats". PLoS ONE 4 (1): e3675. Bibcode 2009PLoSO...4.3675O. doi:10.1371/journal.pone.0003675. PMC 2629844. PMID 19180242. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2629844. 
  3. ^ Altman, J. (1962). "Are new neurons formed in the brains of adult mammals?". Science 135 (3509): 1127–1128. Bibcode 1962Sci...135.1127A. doi:10.1126/science.135.3509.1127. PMID 13860748.  edit
  4. ^ Altman, J. (1963). "Autoradiographic investigation of cell proliferation in the brains of rats and cats". The Anatomical record 145 (4): 573–591. doi:10.1002/ar.1091450409. PMID 14012334.  edit
  5. ^ Altman, J. (1969). "Autoradiographic and histological studies of postnatal neurogenesis. IV. Cell proliferation and migration in the anterior forebrain, with special reference to persisting neurogenesis in the olfactory bulb". The Journal of Comparative Neurology 137 (4): 433–457. doi:10.1002/cne.901370404. PMID 5361244.  edit
  6. ^ Bayer, S. A.; Yackel, J. W.; Puri, P. S. (1982). "Neurons in the rat dentate gyrus granular layer substantially increase during juvenile and adult life". Science 216 (4548): 890–892. Bibcode 1982Sci...216..890B. doi:10.1126/science.7079742. PMID 7079742.  edit
  7. ^ Bayer, S. A. (1982). "Changes in the total number of dentate granule cells in juvenile and adult rats: a correlated volumetric and 3H-thymidine autoradiographic study". Experimental brain research. Experimentelle Hirnforschung. Experimentation cerebrale 46 (3): 315–323. PMID 7095040.  edit
  8. ^ Goldman SA, Nottebohm F (April 1983). "Neuronal production, migration, and differentiation in a vocal control nucleus of the adult female canary brain". Proc Natl Acad Sci U S A. 80 (8): 2390–4. Bibcode 1983PNAS...80.2390G. doi:10.1073/pnas.80.8.2390. PMC 393826. PMID 6572982. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=6572982. 
  9. ^ Reynolds, B. A.; Weiss (Mar 1992). "Generation of neurons and astrocytes from isolated cells of the adult mammalian central nervous system". Science 255 (5052): 1707–1710. Bibcode 1992Sci...255.1707R. doi:10.1126/science.1553558. ISSN 0036-8075. PMID 1553558.  edit
  10. ^ Gage, F. H.; Ray, J.; Fisher, L. J. (1995). "Isolation, Characterization, and use of Stem Cells from the CNS". Annual Review of Neuroscience 18: 159. doi:10.1146/annurev.ne.18.030195.001111. PMID 7605059.  edit
  11. ^ Eriksson PS, Perfilieva E, Björk-Eriksson T, et al. (November 1998). "Neurogenesis in the adult human hippocampus". Nat Med. 4 (11): 1313–7. doi:10.1038/3305. PMID 9809557. 
  12. ^ Gould, E.; Reeves; Fallah; Tanapat; Gross; Fuchs (1999). "Hippocampal neurogenesis in adult Old World primates" (Free full text). Proceedings of the National Academy of Sciences of the United States of America 96 (9): 5263–5267. Bibcode 1999PNAS...96.5263G. doi:10.1073/pnas.96.9.5263. PMC 21852. PMID 10220454. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=10220454.  edit
  13. ^ Ponti G, Peretto B, Bonfanti L (2008). Reh, Thomas A.. ed. "Genesis of neuronal and glial progenitors in the cerebellar cortex of peripuberal and adult rabbits". PLoS ONE 3 (6): e2366. Bibcode 2008PLoSO...3.2366P. doi:10.1371/journal.pone.0002366. PMC 2396292. PMID 18523645. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2396292. 
  14. ^ Gould, E.; Reeves; Graziano; Gross (1999). "Neurogenesis in the neocortex of adult primates". Science 286 (5439): 548–552. doi:10.1126/science.286.5439.548. PMID 10521353.  edit
  15. ^ Zhao, M.; Momma, S.; Delfani, K.; Carlén, M.; Cassidy, R. M.; Johansson, C. B.; Brismar, H.; Shupliakov, O. et al. (2003). "Evidence for neurogenesis in the adult mammalian substantia nigra". Proceedings of the National Academy of Sciences of the United States of America 100 (13): 7925–7930. Bibcode 2003PNAS..100.7925Z. doi:10.1073/pnas.1131955100. PMC 164689. PMID 12792021. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=164689.  edit
  16. ^ Shankle; Rafii, M. S.; Landing, B. H.; Fallon, J. H. (1999). "Approximate doubling of numbers of neurons in postnatal human cerebral cortex and in 35 specific cytoarchitectural areas from birth to 72 months". Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society 2 (3): 244–259. doi:10.1007/s100249900120. PMID 10191348.  edit
  17. ^ Rakic P (February 2002). "Adult neurogenesis in mammals: an identity crisis". J. Neurosci. 22 (3): 614–8. PMID 11826088. 
  18. ^ Kempermann G, Wiskott L, Gage FH (April 2004). "Functional significance of adult neurogenesis". Curr Opin Neurobiol. 14 (2): 186–91. doi:10.1016/j.conb.2004.03.001. PMID 15082323. 
  19. ^ G. Neves, G; S.F. Cooke and T.V. Bliss (2008). "Synaptic plasticity, memory and the hippocampus: A neural network approach to causality". Nature Reviews Neuroscience 9 (1): 65–75. doi:10.1038/nrn2303. PMID 18094707. 
  20. ^ Becker S (2005). "A computational principle for hippocampal learning and neurogenesis". Hippocampus 15 (6): 722–38. doi:10.1002/hipo.20095. PMID 15986407. 
  21. ^ Wiskott L, Rasch MJ, Kempermann G (2006). "A functional hypothesis for adult hippocampal neurogenesis: avoidance of catastrophic interference in the dentate gyrus". Hippocampus 16 (3): 329–43. doi:10.1002/hipo.20167. PMID 16435309. 
  22. ^ Aimone JB, Wiles J, Gage FH (June 2006). "Potential role for adult neurogenesis in the encoding of time in new memories". Nat Neurosci. 9 (6): 723–7. doi:10.1038/nn1707. PMID 16732202. 
  23. ^ Shors TJ, Townsend DA, Zhao M, Kozorovitskiy Y, Gould E (2002). "Neurogenesis may relate to some but not all types of hippocampal-dependent learning". Hippocampus 12 (5): 578–84. doi:10.1002/hipo.10103. PMID 12440573. 
  24. ^ Meshi D, Drew MR, Saxe M, et al. (June 2006). "Hippocampal neurogenesis is not required for behavioral effects of environmental enrichment". Nat Neurosci. 9 (6): 729–31. doi:10.1038/nn1696. PMID 16648847. 
  25. ^ Gould, E.; Beylin, A.; Tanapat, P.; Reeves, A.; Shors, T. J. (1999). "Learning enhances adult neurogenesis in the hippocampal formation". Nature neuroscience 2 (3): 260–265. doi:10.1038/6365. PMID 10195219.  edit
  26. ^ Malberg JE, Eisch AJ, Nestler EJ, Duman RS (December 2000). "Chronic antidepressant treatment increases neurogenesis in adult rat hippocampus". J Neurosci. 20 (24): 9104–10. PMID 11124987. http://www.jneurosci.org/cgi/pmidlookup?view=long&pmid=11124987. 
  27. ^ Manev H, Uz T, Smalheiser NR, Manev R (January 2001). "Antidepressants alter cell proliferation in the adult brain in vivo and in neural cultures in vitro". Eur J Pharmacol. 411 (1-2): 67–70. doi:10.1016/S0014-2999(00)00904-3. PMID 11137860. http://linkinghub.elsevier.com/retrieve/pii/S0014-2999(00)00904-3. 
  28. ^ Santarelli L, Saxe M, Gross C, et al. (August 2003). "Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants". Science 301 (5634): 805–9. Bibcode 2003Sci...301..805S. doi:10.1126/science.1083328. PMID 12907793. 
  29. ^ Schloesser RJ, Manji HK, Martinowich K (April 2009). "Suppression of adult neurogenesis leads to an increased hypothalamo-pituitary-adrenal axis response.". Neuroreport 20 (6): 553–7. doi:10.1097/WNR.0b013e3283293e59. PMC 2693911. PMID 19322118. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0959-4965&volume=20&issue=6&spage=553. 
  30. ^ Surget A, Tanti A, Leonardo ED et al. (May 2011). "Antidepressants recruit new neurons to improve stress response regulation.". Molecular Psychiatry (advance online publication). doi:10.1038/mp.2011.48. PMID 21537331. http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201148a.html. 
  31. ^ Castrén E (March 2005). "Is mood chemistry?". Nat Rev Neurosci. 6 (3): 241–6. doi:10.1038/nrn1629. PMID 15738959. 
  32. ^ Mirescu C, Peters JD, Noiman L, Gould E (December 2006). "Sleep deprivation inhibits adult neurogenesis in the hippocampus by elevating glucocorticoids". Proc Natl Acad Sci U S A. 103 (50): 19170–5. Bibcode 2006PNAS..10319170M. doi:10.1073/pnas.0608644103. PMC 1748194. PMID 17135354. http://www.pnas.org/cgi/content/abstract/103/50/19170?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=neurogenesis+sleep&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT. 
  33. ^ a b c Arias-Carrión O, Freundlieb N, Oertel WH, Höglinger GU (October 2007). "Adult neurogenesis and Parkinson's disease". CNS Neurol Disord Drug Targets. 6 (5): 326–35. doi:10.2174/187152707783220875. PMID 18045161. http://www.bentham-direct.org/pages/content.php?CNSNDDT/2007/00000006/00000005/0005Z.SGM. 
  34. ^ Fallon J, Reid S, Kinyamu R, et al. (December 2000). "In vivo induction of massive proliferation, directed migration, and differentiation of neural cells in the adult mammalian brain". Proc Natl Acad Sci U S A. 97 (26): 14686–91. Bibcode 2000PNAS...9714686F. doi:10.1073/pnas.97.26.14686. PMC 18979. PMID 11121069. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=18979. 
  35. ^ Arias-Carrión O, Verdugo-Díaz L, Feria-Velasco A, et al. (October 2004). "Neurogenesis in the subventricular zone following transcranial magnetic field stimulation and nigrostriatal lesions". J Neurosci Res. 78 (1): 16–28. doi:10.1002/jnr.20235. PMID 15372495. 
  36. ^ Arias-Carrión O, Hernández-López S, Ibañez-Sandoval O, Bargas J, Hernández-Cruz A, Drucker-Colín R (November 2006). "Neuronal precursors within the adult rat subventricular zone differentiate into dopaminergic neurons after substantia nigra lesion and chromaffin cell transplant". J Neurosci Res. 84 (7): 1425–37. doi:10.1002/jnr.21068. PMID 17006899. 
  37. ^ a b Höglinger GU, Rizk P, Muriel MP, et al. (July 2004). "Dopamine depletion impairs precursor cell proliferation in Parkinson disease". Nat Neurosci. 7 (7): 726–35. doi:10.1038/nn1265. PMID 15195095. 
  38. ^ a b Flores C, Rodaros D, Stewart J (November 1998). "Long-lasting induction of astrocytic basic fibroblast growth factor by repeated injections of amphetamine: blockade by concurrent treatment with a glutamate antagonist". Journal of Neuroscience 18 (22): 9547–55. PMID 9801391. http://www.jneurosci.org/cgi/pmidlookup?view=long&pmid=9801391. 
  39. ^ a b Flores C, Stewart J (August 2000). "Basic fibroblast growth factor as a mediator of the effects of glutamate in the development of long-lasting sensitization to stimulant drugs: studies in the rat". Psychopharmacology 151 (2-3): 152–65. doi:10.1007/s002130000417. PMID 10972461. http://link.springer.de/link/service/journals/00213/bibs/0151002/01510152.htm. 
  40. ^ a b Flores C, Samaha AN, Stewart J (January 2000). "Requirement of endogenous basic fibroblast growth factor for sensitization to amphetamine". Journal of Neuroscience 20 (2): RC55. PMID 10632621. http://www.jneurosci.org/cgi/pmidlookup?view=long&pmid=10632621. 
  41. ^ a b Pierce RC, Bari AA (2001). "The role of neurotrophic factors in psychostimulant-induced behavioral and neuronal plasticity". Reviews in the Neurosciences 12 (2): 95–110. PMID 11392459. 
  42. ^ a b Mueller D, Chapman CA, Stewart J (February 2006). "Amphetamine induces dendritic growth in ventral tegmental area dopaminergic neurons in vivo via basic fibroblast growth factor". Neuroscience 137 (3): 727–35. doi:10.1016/j.neuroscience.2005.09.038. PMID 16338078. http://linkinghub.elsevier.com/retrieve/pii/S0306-4522(05)01081-X. 
  43. ^ a b Lazarov O, Robinson J, Tang YP, Hairston IS, Korade-Mirnics Z, Lee VM, Hersh LB, Sapolsky RM, Mirnics K, Sisodia SS (March 2005). "Environmental enrichment reduces Abeta levels and amyloid deposition in transgenic mice". Cell 120 (5): 701–13. doi:10.1016/j.cell.2005.01.015. PMID 15766532. 
  44. ^ van Praag H, Shubert T, Zhao C, Gage FH (September 2005). "Exercise enhances learning and hippocampal neurogenesis in aged mice". J. Neurosci. 25 (38): 8680–5. doi:10.1523/JNEUROSCI.1731-05.2005. PMC 1360197. PMID 16177036. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1360197. 
  45. ^ von Bohlen und Halbach O (2010). "Involvement of BDNF in age-dependent alterations in the hippocampus". Front Aging Neurosci 2. doi:10.3389/fnagi.2010.00036. PMC 2952461. PMID 20941325. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2952461. 
  46. ^ Marx CE, Trost WT, Shampine LJ, et al. (December 2006). "The neurosteroid allopregnanolone is reduced in prefrontal cortex in Alzheimer's disease". Biol. Psychiatry 60 (12): 1287–94. doi:10.1016/j.biopsych.2006.06.017. PMID 16997284. 
  47. ^ Wang JM, Singh C, Liu L, Irwin RW, Chen S, Chung EJ, Thompson RF, Brinton RD (2010). "Allopregnanolone reverses neuron and cognitive deficits in a mouse model of Alzheimer's disease" (PDF). Proc Natl Acad Sci U S A. 107 (14): 6498–6503. Bibcode 2010PNAS..107.6498W. doi:10.1073/pnas.1001422107. PMC 2851948. PMID 20231471. http://www.pnas.org/content/107/14/6498.full.pdf. 
  48. ^ Van Praag, H.; Shubert, T.; Zhao, C.; Gage, F. (2005). "Exercise enhances learning and hippocampal neurogenesis in aged mice". Journal of Neuroscience 25 (38): 8680–8685. doi:10.1523/JNEUROSCI.1731-05.2005. PMC 1360197. PMID 16177036. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1360197.  edit
  49. ^ Van Praag, H.; Kempermann, G.; Gage, F. (1999). "Running increases cell proliferation and neurogenesis in the adult mouse dentate gyrus". Nature neuroscience 2 (3): 266–270. doi:10.1038/6368. PMID 10195220.  edit
  50. ^ Bjørnebekk A, Mathé AA, Brené S (September 2005). "The antidepressant effect of running is associated with increased hippocampal cell proliferation". Int J Neuropsychopharmacol 8 (3): 357–68. doi:10.1017/S1461145705005122. PMID 15769301. 
  51. ^ Jin K, Wang X, Xie L, et al. (August 2006). "Evidence for stroke-induced neurogenesis in the human brain". Proc. Natl. Acad. Sci. U.S.A. 103 (35): 13198–202. Bibcode 2006PNAS..10313198J. doi:10.1073/pnas.0603512103. PMC 1559776. PMID 16924107. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1559776. 
  52. ^ Parent JM; Elliott, RC; Pleasure, SJ; Barbaro, NM; Lowenstein, DH (2006). "Aberrant seizure-induced neurogenesis in experimental temporal lobe epilepsy". Ann Neurol 59 (1): 81–91. doi:10.1002/ana.20699. PMID 16261566. 
  53. ^ Gerber J, Tauber SC, Armbrecht I, Schmidt H, Brück W, Nau R (2009). "Increased neuronal proliferation in human bacterial meningitis". Neurology 73 (13): 1026–32. doi:10.1212/WNL.0b013e3181b9c892. PMID 19786694. 
  54. ^ Lee AL, Ogle WO, Sapolsky RM (April 2002). "Stress and depression: possible links to neuron death in the hippocampus". Bipolar Disord. 4 (2): 117–28. doi:10.1034/j.1399-5618.2002.01144.x. PMID 12071509. http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=1398-5647&date=2002&volume=4&issue=2&spage=117. 
  55. ^ Sheline YI, Gado MH, Kraemer HC (August 2003). "Untreated depression and hippocampal volume loss". Am J Psychiatry. 160 (8): 1516–8. doi:10.1176/appi.ajp.160.8.1516. PMID 12900317. http://ajp.psychiatryonline.org/cgi/pmidlookup?view=long&pmid=12900317. 
  56. ^ Jiang, W.; Zhang, Y.; Xiao, L.; Van Cleemput, J.; Ji, S.; Bai, G.; Zhang, X. (2005). "Cannabinoids promote embryonic and adult hippocampus neurogenesis and produce anxiolytic- and antidepressant-like effects". The Journal of clinical investigation 115 (11): 3104–3116. doi:10.1172/JCI25509. PMC 1253627. PMID 16224541. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1253627.  edit
  57. ^ Saul A. Villeda, Jian Luo, Kira I. Mosher, Bende Zou, Markus Britschgi, Gregor Bieri, Trisha M. Stan, Nina Fainberg, Zhaoqing Ding, Alexander Eggel, Kurt M. Lucin, Eva Czirr, Jeong-Soo Park, Sebastien Couillard-Despres, Ludwig Aigner, Ge Li, Elaine R. Peskind, Jeffrey A. Kaye, Joseph F. Quinn, Douglas R. Galasko, Xinmin S. Xie, Thomas A. Rando & Tony Wyss-Coray (September 2011). "The ageing systemic milieu negatively regulates neurogenesis and cognitive function". Nature 477 (7362): 90–94. doi:10.1038/nature10357. PMID 21886162. 
  58. ^ Wen Jiang; Yun Zhang; Lan Xiao; Jamie Van Cleemput; Shao-Ping Ji; Guang Bai; Xia Zhang (2005-11-01). "Cannabinoids promote embryonic and adult hippocampus neurogenesis and produce anxiolytic- and antidepressant-like effects". Journal of Clinical Investigation 115 (11): 3104–16. doi:10.1172/JCI25509. PMC 1253627. PMID 16224541. http://www.jci.org/articles/view/25509. Retrieved 2011-03-02. 
Notes

External links

v · d · ePrenatal development/Mammalian development of nervous system (GA 9.733 and GA 10.1002, TE E5.13-16)
Neurogenesis
Cranial neural crest (Cardiac neural crest complex) · Truncal neural crest
Eye development
Auditory development
note: NS is mostly ectoderm, but mesoderm is precursor for epineurium, perineurium, and endoneurium

M: CNS

anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

M: EYE

anat(g/a/p)/phys/devp/prot

noco/cong/tumr, epon

proc, drug(S1A/1E/1F/1L)

M: EAR

anat(e/p)/phys/devp

noco/cong, epon

proc, drug(S2)

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