Yaşlanma ve kısa dönem kalori kısıtlamasının zebra balığı (danio rerio) beyninde nörogenez ve hücresel yaşlanma üzerindeki etkileri

We know from previous studies that adult neuron generation still continues in old animals. This process occurs mainly in hippocampal region, which is analogous to a region in telencephalon of the zebrafish brain. As dietary restriction (DR) was known to extend life span, we hypothesized that DR should also alleviate several age associated alterations. We tested a 10-week dietary regimen in young and old, male and female 124 fish. Results showed that a significant loss of body weight in both young and old DR groups was observed without an effect on body lengths. To label actively dividing cells we used BrdU, which is a thymidine analog. We obtained cross-sectional slices with vibratome, performed immunostaining with antibodies against BrdU, NeuN, HuC; and visualized the brain sections with confocal microscopy. We counted the BrdU positive cells in all brain slices and documented the specific regions where the adult neurogenesis dominates the most and least. We confirmed that there are more BrdU positive cells in young animals than olds, and that age is correlated with an increased senescence associated beta-galactosidase activity, along with shortened telomere lengths. Diet was not found to be creating a significant change in cell proliferation rates, cellular senescence, or cellular differentiation, but a shortening effect on telomere lengths. Suggesting that the potential effects of DR could be related to telomere regulation, to detect differentially expressed genes related to this mechanism, we performed microarray analysis. Initial data indicated no significant effect of diet on gene expression differences among aged fish.