Figure 1.

Schematic of experimental design. F0 male mice were exposed to vehicle (VEH, n=5) or nicotine (NIC, n=7) and mated (dashed line) to produce F1 offspring. Resulting F1 males and females were randomly distributed to chronic unpredictable stress (CUS) or no stress control (CON) condition and mated to produce F2 offspring. Of note, mice from a given litter were distributed evenly into CUS or CON groups, such that the resulting CUS or CON groups were comprised of mice from at least 5–7 different litters. One half of the F2 offspring were tested for locomotor sensitization to NIC (solid line) while the other half of the behaviorally-naive F2 mice were mated to produce the F3 offspring. As before, F3 mice from a single litter were evenly distributed to nicotine or saline treatments and tested for locomotor sensitization.