Matches in SemOpenAlex for { <https://semopenalex.org/work/W2142015825> ?p ?o ?g. }
- W2142015825 abstract "Unlike mammals, adult salamanders can regenerate their brain after injury in a process fuelled by neurogenesis. The aim of this thesis is to identify the cells that give rise to new neurons after injury and examine the mechanisms controlling the initiation and termination of brain regeneration in the newt. The reasons why newts can regenerate their brain while mammals cannot are unknown, and it has been argued that the presence of constantly proliferating cells is a prerequisite for regeneration to occur. In Paper I of this thesis we mapped the distribution of proliferating cells in the adult newt brain and identified the areas of the brain where neurons are added under normal conditions. We observed that similarly to mammals, neurons are continuously added to the newt forebrain, while no neurogenesis was detected in the midbrain. After injury to the newt midbrain, radial glia-like cells (RGLs) start to proliferate and progeny of these cells differentiate into neurons. These results show that regeneration is not dependent on constitutive neurogenesis. In Paper II we wanted to test if the neurotransmitter dopamine is involved in controlling regeneration of dopaminergic (DA) neurons. We found that synthetically increasing the concentration of dopamine in the regenerating newt brain by administration of the dopamine precursor L-dopa, inhibits regeneration by blocking the proliferation of the progenitor cells. We also found that antagonizing dopamine signalling in the uninjured brain is sufficient to evoke proliferation of the otherwise quiescent RGLs and we found that progeny of these cells give rise to increased numbers of neurons in the midbrain. The newt is not the only vertebrate animal able to regenerate its brain; both fish and reptile species can repair injured brain. Interestingly, fish and reptiles are also able to survive hypoxia and are exposed to these conditions in their natural habitat. In Paper III of my thesis we wanted to examine if the ability to regenerate brain tissue is linked to an animal’s ability to survive varying levels of oxygen. We observed that the red spotted newt is able to survive hypoxia, but this treatment leads to increased cell death in the brain. Reoxygenation of the brain leads to an elevated production of reactive oxygen species, which is concomitant with an increase in proliferation of the ventricular progenitor cells, suggesting that a regenerative process has been initiated. Inhibiting production of reactive oxygen species during reoxygenation results in reduced progenitor cell proliferation. The major findings of this thesis are summarized as follows: the red spotted newt is able to regenerate areas of the brain that are normally devoid of proliferating cells. In this process, ventricular RGLs act as progenitor cells in the adult newt brain and give rise to new neurons after injury. We have also shown that the neurotransmitter dopamine inhibits the proliferation of DA progenitor cells in a feedback-like manner and thus identified a mechanism for how the brain senses the degree of neuronal loss. These results pinpoint several features of naturally occurring brain regeneration and could aid the development of techniques to evoke brain regeneration in humans. Finally we have found that the newt, similarly to other animals capable of brain regeneration, is able to survive hypoxia. Hypoxia leads to increased cell death in the brain, but molecules that are activated by reoxygenation induce regenerative mechanisms such as increased proliferation of neural progenitor cells. These discoveries suggest that the trait of brain regeneration has evolved together with the capacity to survive variation in oxygen levels. LIST OF PUBLICATIONS I. Daniel A Berg, Matthew Kirkham, Anna Beljajeva, Dunja Knapp, Bianca Habermann, Jesper Ryge Elly M Tanaka and Andras Simon (2010) Efficient regeneration by activation of neurogenesis in homeostatically quiescent regions of the adult vertebrate brain. Development, 137:4127-4134. II. Daniel A Berg, Matthew Kirkham, Heng Wang and Andras Simon (2011) Dopamine controls neurogenesis in the adult salamander midbrain under homeostasis and during regeneration of dopamine neurons. Cell Stem Cell 2011, 8, 426-433. III. Daniel A Berg, Lasse D Jensen, Yihai Cao and Andras Simon Reoxygenation after systemic hypoxia induces tissue damages and activates regenerative mechanisms in the adult newt brain. Manuscript" @default.
- W2142015825 created "2016-06-24" @default.
- W2142015825 creator A5070848691 @default.
- W2142015825 date "2012-09-06" @default.
- W2142015825 modified "2023-09-27" @default.
- W2142015825 title "Regenerating the brain : lessons from the Red Spotted Newt" @default.
- W2142015825 cites W1482293895 @default.
- W2142015825 cites W1484380619 @default.
- W2142015825 cites W1495473347 @default.
- W2142015825 cites W1503339375 @default.
- W2142015825 cites W1503727145 @default.
- W2142015825 cites W1504584187 @default.
- W2142015825 cites W1517125774 @default.
- W2142015825 cites W1526271356 @default.
- W2142015825 cites W1527671059 @default.
- W2142015825 cites W1535542941 @default.
- W2142015825 cites W1536502239 @default.
- W2142015825 cites W1552958657 @default.
- W2142015825 cites W155609149 @default.
- W2142015825 cites W1557793818 @default.
- W2142015825 cites W1558592065 @default.
- W2142015825 cites W1569683384 @default.
- W2142015825 cites W1574542597 @default.
- W2142015825 cites W1584249535 @default.
- W2142015825 cites W1587940136 @default.
- W2142015825 cites W1596264327 @default.
- W2142015825 cites W1603509064 @default.
- W2142015825 cites W1632789112 @default.
- W2142015825 cites W1709926499 @default.
- W2142015825 cites W1733539716 @default.
- W2142015825 cites W1746916277 @default.
- W2142015825 cites W1768302124 @default.
- W2142015825 cites W1840778526 @default.
- W2142015825 cites W1874198492 @default.
- W2142015825 cites W1877873625 @default.
- W2142015825 cites W1889082107 @default.
- W2142015825 cites W1894242559 @default.
- W2142015825 cites W1894632965 @default.
- W2142015825 cites W1897919376 @default.
- W2142015825 cites W1902532212 @default.
- W2142015825 cites W1917194358 @default.
- W2142015825 cites W1921111806 @default.
- W2142015825 cites W1925492557 @default.
- W2142015825 cites W1926043920 @default.
- W2142015825 cites W1938260325 @default.
- W2142015825 cites W1938938901 @default.
- W2142015825 cites W1950277249 @default.
- W2142015825 cites W1951175395 @default.
- W2142015825 cites W1956591954 @default.
- W2142015825 cites W1963940970 @default.
- W2142015825 cites W1964868517 @default.
- W2142015825 cites W1966295032 @default.
- W2142015825 cites W1967802833 @default.
- W2142015825 cites W1968151094 @default.
- W2142015825 cites W1968770991 @default.
- W2142015825 cites W1968840425 @default.
- W2142015825 cites W1969032959 @default.
- W2142015825 cites W1969684909 @default.
- W2142015825 cites W1969800514 @default.
- W2142015825 cites W1969887716 @default.
- W2142015825 cites W1971389338 @default.
- W2142015825 cites W1971806697 @default.
- W2142015825 cites W1973174453 @default.
- W2142015825 cites W1973297960 @default.
- W2142015825 cites W1974552797 @default.
- W2142015825 cites W1974765744 @default.
- W2142015825 cites W1974791004 @default.
- W2142015825 cites W1976320341 @default.
- W2142015825 cites W1976401364 @default.
- W2142015825 cites W1976814021 @default.
- W2142015825 cites W1978056714 @default.
- W2142015825 cites W1980050845 @default.
- W2142015825 cites W1980499453 @default.
- W2142015825 cites W1980706080 @default.
- W2142015825 cites W1981692093 @default.
- W2142015825 cites W1982025080 @default.
- W2142015825 cites W1982091995 @default.
- W2142015825 cites W1982603620 @default.
- W2142015825 cites W1983456059 @default.
- W2142015825 cites W1983488393 @default.
- W2142015825 cites W1986408320 @default.
- W2142015825 cites W1987145582 @default.
- W2142015825 cites W1987758998 @default.
- W2142015825 cites W1987980866 @default.
- W2142015825 cites W1988352722 @default.
- W2142015825 cites W1988354925 @default.
- W2142015825 cites W1989020172 @default.
- W2142015825 cites W1989416066 @default.
- W2142015825 cites W1989696297 @default.
- W2142015825 cites W1990161015 @default.
- W2142015825 cites W1990984249 @default.
- W2142015825 cites W1992824352 @default.
- W2142015825 cites W1994345197 @default.
- W2142015825 cites W1994489873 @default.
- W2142015825 cites W1994532676 @default.
- W2142015825 cites W1995188451 @default.
- W2142015825 cites W1996646868 @default.
- W2142015825 cites W1996739924 @default.
- W2142015825 cites W1996907803 @default.
- W2142015825 cites W1997389247 @default.