Fig. 5.

Proportion of control dams exhibiting preference for each chamber or lacking a chamber preference (a) and mean times spent in each chamber (b) of the CPP apparatus during the preconditioning (solid bars) and postconditioning (hatched bars) sessions. Control dams were not exposed to unconditioned stimuli in the conditioning chambers but were conditioned for identical lengths as experimental dams, either 2 h (“pup-associated length”) or 30 min (“cocaine-associated length”). Graphs include data from both postpartum groups. Proportions of dams placed into each preference category differed significantly from each other and differed between sessions; chamber times were equal between side chambers during both sessions but selectively differed from the center chamber (number sign); all P<0.05