Meeting Abstract

P1.176  Wednesday, Jan. 4  Neurogenesis in the Injured Red-Sided Garter Snake Brain SMEETS, J.*; KROHMER, R. W.; Saint Xavier University, Chicago; Saint Xavier University, Chicago

Injury to the homeotherm brain results in the upregulation of the estrogen-synthesizing enzyme aromatase. While peripheral estrogens have been shown to be neurogenic in birds and mammals, the effect of local estrogen provision in the reptilian brain has not been examined. To determine whether or not injury-induced aromatization and or, local estrogen provision can affect neurogenesis following mechanical brain damage, adult male red-sided garter snakes were castrated, implanted with either an empty silastic tube or tubes containing either testosterone or estradiol. A second set of intact animals received a silastic implant containing the anti-aromatase 1, 4, 6-androstatriene-3, 17-dione (ATD). Fourteen days after implantation, animals were given a unilateral penetrating brain injury. All animals were then injected with the thymidine analog 5-Bromo-2’-deoxyuridine (BrdU) on the following schedule: immediately following surgery, 24 hours after surgery and 24 hours prior to perfusion. Animals were perfused at 10, 14 and 21 days post surgery. Two equivalent sets of coronal sections were collected on gelatin coated slides. One set was labeled using an antibody against BrdU while the second set was visualized for the aromatase enzyme. Sections containing the injury site and surrounding areas (III ventricle and preoptic area (POA) were examined for neurogenesis and aromatase immunoreactivity. The total number of BrdU positive and aromatase immunoreactive cells were counted and their locations were recorded.