Sprague dawley timed pregnant dams

All experiments were performed in accordance with the University of Alabama at Birmingham Institutional Animal Care and Use Committee. Sprague-Dawley timed pregnant dams and adult male rats (90-120 days old) were purchased from Charles River Laboratories (Wilmington, MA). Dams were individually housed until embryonic day 18 (E18) for cell culture harvest. Male adult rats were co-housed in pairs in plastic filtered cages with nesting enrichment in an AAALAC-approved animal care facility maintained between 23-24°C on a 12hr light/dark cycle with ad libitum food (Lab Diet Irradiated rat chow) and water. Bedding and enrichment were changed weekly by animal resources program staff. Animals were randomly assigned to experimental groups. Gadd45b knockout mice for the cocaine conditioned place preference experiment were bred at the University of Alabama at Birmingham on a B6:129VJ background, as described previously [27, 28] . Male wildtype and mutant offspring from heterozygotes were used for behavioral testing. Mice aged 2-6 months were individually housed at least 3 days prior to the start of behavioral testing. Heterozygotes were bred with C57BL/6 wild-types for at least six generations to generate back-crossed mice. All animals were handled for 3-5 days prior to behavioral testing.