[Abstract Title]. - Society for Neuroscience

Two pups per litter were euthanized for anatomical studies (by transcardial aldehyde perfusion)
or biochemical analysis (decapitated and quick-frozen). The numbers of VB neurons rose more
quickly and peaked sooner in Et-treated pups, but by P30 there was no treatment-induced
difference in the numbers. Cell cycle kinetics for the proliferative population was determined on
P6 using a cumulative bromodeoxyuridine (BrdU; 25 mg/kg) labeling method. Ethanol did not
affect the proportion of cycling cells in the VB, but it did alter the cell cycle kinetics. The total
length of the cell cycle (Tc) was shorter in Et-exposed rats (11.4 ± 0.9 hr) than in controls (17.3 ±
1.1 hr). The length of S-phase (Ts) was also shorter in Et-treated pups (4.2 ± 0.3 hr) than in
controls (7.0 ± 0.9 hr). Enzyme linked immunosorbant assays and immunoblots were used to
determine the expression of NGF and BDNF and their receptors, respectively. Ethanol increased
NGF expression at all ages examined, but it had no effect on the expression of either BDNF or
the neurotrophin receptors. The results show that prenatal exposure to ethanol increases the
proliferation of VB neural progenitors. It appears that this effect is mediated by NGF.
Disclosures: S.M. Mooney , None; M.W. Miller, None.
Poster
229. Neuronal and Glial Proliferation III
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 229.21/A21
Topic: A.02.a. Proliferation
Support: NSF Grant 541602
Title: Circadian variations of cell proliferation in the dentate gyrus of the adult hamster
Authors: *J. M. HEITZER, J. SWANN;
Lehigh Univ., Bethlehem, PA
Abstract: Variations in DNA synthesis have been found between day and night in many
mammalian tissues, such as liver, skin, and intestinal epithelium, suggesting that circadian
rhythms affect the timing of cell division in these tissues. However, there is little information
about a diurnal rhythm of cell proliferation in the central nervous system of mammals. In the
adult rodent, the dentate gyrus is one of the main sites of cell proliferation. The goal of this study
was to determine whether there are circadian rhythms of cell proliferation in the dentate gyrus of
adult male hamsters using the marker BrdU. BrdU is a thymidine analog incorportated into the
cells‟ DNA during cell division. Adult male hamsters were maintained on a 14:10 light-dark
cycle, with ad lib access to food and water and randomly assigned to four different groups. Each
group was injected with BrdU (300 mg/kg, i.p.) at one of four time points, the time points