Meeting Abstract
P3.194 Monday, Jan. 6 15:30 Neurogenesis and the expression of doublecortin in the cortex of Sceloporus occidentalis WILSON, RC*; BARRIGA-HERNANDEZ, J; NELSON, MB; LOUPY, KM; YOUNG, KM; BARNO, AR; STRAND, CR; Cal Poly State University, San Luis Obispo; Allan Hancock College, Santa Maria; Allan Hancock College, Santa Maria; Cal Poly State University, San Luis Obispo; Cal Poly State University, San Luis Obispo; Cal Poly State University, San Luis Obispo; Cal Poly State University, San Luis Obispo cstrand@calpoly.edu
In reptiles, plasticity of the medial and dorsal cortices (MC and DC) is related to spatial memory and spatial ecology. Furthermore, adult neurogenesis occurs in these regions, especially the medial cortex. However, little is known about the relationship between spatial learning and the proliferation or survival of newly born neurons in these regions. In order to investigate these processes, we need more information about neurogenesis in lizards. In other vertebrates, doublecortin (DCX) is a protein expressed in immature neurons and staining for this protein can be used to quantify neurogenesis. In this experiment, we injected adult male Sceloporus occidentalis with Bromodeoxyuridine (BrdU), a cell birth marker, and sacrificed them 2 days or 1, 2, 4 or 6 weeks after injection. Coronal sections were double-stained via immunofluorescence for BrdU and DCX to determine the time course of DCX expression and how long it takes new neurons to migrate to the cell layer of the MC. As expected, cells are born along the ventricles and migrate through the inner plexiform layer (IPL) and into the cell layer (CL) of the MC. The number of double-labeled cells is initially high in the ventricular zone and IPL (2d-2wks), increasing in the CL later (4-6wks). However, the total number of BrdU-labeled cells decreases by 6 weeks, indicating that many of the newly born cells die by this time. This information will be used to help design experiments to determine how spatial learning may affect different aspects of neurogenesis in the reptile brain, from proliferation to migration and survival.
