| 1. |
- Eriksson, Peter S, 1959, et al.
(författare)
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Neurogenesis in the adult human hippocampus
- 1998
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Ingår i: Nat Med. - 1078-8956. ; 4:11, s. 1313-7
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Tidskriftsartikel (refereegranskat)abstract
- The genesis of new cells, including neurons, in the adult human brain has not yet been demonstrated. This study was undertaken to investigate whether neurogenesis occurs in the adult human brain, in regions previously identified as neurogenic in adult rodents and monkeys. Human brain tissue was obtained postmortem from patients who had been treated with the thymidine analog, bromodeoxyuridine (BrdU), that labels DNA during the S phase. Using immunofluorescent labeling for BrdU and for one of the neuronal markers, NeuN, calbindin or neuron specific enolase (NSE), we demonstrate that new neurons, as defined by these markers, are generated from dividing progenitor cells in the dentate gyrus of adult humans. Our results further indicate that the human hippocampus retains its ability to generate neurons throughout life.
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| 2. |
- Johansson, Barbro, et al.
(författare)
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Postischemic housing in an enriched environment influences hippocampal progenitor cell differentiation after focal cortical ischemia
- 2004
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Ingår i: Maturation Phenomenon in Cerebral Ischemia V. - 9783540408741 ; , s. 297-308
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Konferensbidrag (refereegranskat)abstract
- We have tested the hypothesis that environmental factors can influence postischemic progenitor cell survival and differentiation in the dentate gyrus. The proliferation marker bromodeoxyuridine (BrdU) was administered during 7 days starting 24 h after ligation of the right middle cerebral artery. Postoperatively the rats were housed in standard cages or transferred to enriched environment 24 h or 7 days after the ligation. Rats housed in standard cages performed significantly worse than rats housed in an enriched environment in a leg placement and a rotating pole test four weeks after the arterial ligation. Neurogenesis and gliogenesis were determined by triple labeling with antibodies against BrdU, the astrocytic marker glial fibrillary acidic protein (GFAP), and the neuronal markers Calbindin D28k and NeuN. Rats with cortical lesions had a 5- to 6-fold increase in BrdU labeled cells on the ipsilateral side (p<0.001 for the delayed enriched group; p<0.01 for the early enriched and standard groups) and a 2- to 3-fold non-significant increase on the contralateral side with no significant differences between the groups. About 80% of the BrdU-positive cells co-labeled with NeuN and about 70% of the BrdU-positive cells co-labeled with Calbindin D28K. Although housing conditions did not influence neurogenesis it markedly altered gliogenesis. Whereas the standard group did not have more astrocytes than sham-operated rats on the ipsilateral side, the early and delayed enriched group had a 3- to 5-fold increase, respectively, thereby normalizing the severely disturbed neuron to glia ratio in the standard group. We hypothesize that the newly formed neurons in the standard group would have a poor environment in the absence of a concomitant gliogenesis. Astrocytes play an important role in neuronal plasticity, and we propose that more attention should be given to gliogenesis in experimental studies on cell proliferation and differentiation after brain lesions.
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| 3. |
- Komitova, M, et al.
(författare)
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Effects of cortical ischemia and postischemic environmental enrichment on hippocampal cell genesis and differentiation in the adult rat
- 2002
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016 .- 0271-678X. ; 22:7, s. 852-860
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Tidskriftsartikel (refereegranskat)abstract
- The study aimed to elucidate the effects of cortical ischemia and postischemic environmental enrichment on hippocampal cell genesis. A cortical infarct was induced by it permanent ligation of the middle cerebral artery distal to the striatal branches in 6-month-old spontaneously hypertensive rats. Bromodeoxyuridine (BrdU) was administered as 7 consecutive daily injections starting 24 hours after surgery and animals were housed in standard or enriched environment. Four weeks after completed BrdU administration, BrdU incorporation and its co-localization with the neuronal markers NeuN and calbindin D28k, and the astrocytic marker glial fibrillary acidic protein in the granular cell layer and sub,granular zone of the hippocampal dentate gyrus were determined with immunohistochemistry and were quantified stereologically. Compared with sham-operated rats, rats with cortical infarcts had a five- to sixfold ipsilateral increase in BrdU-labeled cells. About 80% of the new cells were neurons. Differential postischemic housing did not influence significantly the total number Of Surviving BrdU-labeled cells or newborn neurons. However, postischemic environmental enrichment increased the ipsilateral generation of astrocytes normalizing the astrocyte-to-neuron ratio. which was significantly reduced in rats housed in standard environment postischemically.
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