Corticosterone measurement.

Serum samples were collected after animal sacrifice via blood collection from the eye. Briefly, the eye was removed, and blood was collected in a BD microtainer serum gel tube. Blood was allowed to fully clot for 45 minutes at room temperature and serum was collected by centrifugation at 15,000 g for 90 seconds and collection of supernatant (serum). Serum samples were frozen at –80°C until analysis by the University of Virginia Ligand Assay and Analysis Core using a mouse and rat corticosterone ELISA (IBL).