Meeting Abstract
P2.191 Saturday, Jan. 5 Effect of Caloric Restriction on Longevity and Neurogenesis in the House Cricket, Acheta domesticus ORNELAS, L; KOK, L; FUSE, M; MOFFATT, C*; University of California, San Diego; San Francisco State University, CA; San Francisco State University, CA; San Francisco State University, CA moffatt@sfsu.edu
Caloric restriction increases lifespan in many vertebrate and invertebrate species. However, relatively few studies have examined how caloric restriction affects age-related changes in the nervous system. We addressed this issue by determining how age and caloric restriction affected the rate of cell divisions by neuroblasts, cells that function in a manner similar to mammalian neural stem cells, in cricket brains. In our first experiment, newly emerged adult crickets were either calorically restricted (CR) by feeding them only every other day or they were allowed to feed freely (FF). We found that on average FF crickets died significantly sooner than did CR crickets, at 69 versus 95 days of age, respectively. In our second experiment, we injected FF and CR crickets with bromodeoxyuridine (BrdU) two hours before euthanizing them at either 10 or 90 days of age. Using the incorporation of BrdU into cell nuclei as a marker for cell proliferation, we found that neither age nor caloric restriction affected the number of BrdU-labeled cells. However, we did find evidence that caloric restriction might prevent age-related changes in the gross morphology of the brain. In young crickets, neuroblasts are located in clusters that are symmetrical in appearance and location, while in old crickets these clusters become asymmetrical. Using a Chi-square test to make comparisons between old FF and old CR crickets, we found that fewer old CR crickets than expected had asymmetrical clusters of neuroblasts. Overall, our results suggest caloric restriction may mitigate at least one effect of aging on the cricket brain. Further experiments will determine if the differences in the brain morphology of old FF and CR crickets are correlated with differences in behavior.
