@entity1239 enhances the locomotor stimulating but not the conditioned rewarding effect of XXXX in DBA/2J @entity19 .

@entity167 @entity19 @entity1239 @entity1068
BACKGROUND: One hypothesis to explain the high rate of @entity1239 and @entity167 ( @entity1068 [ @entity167 ]) co-abuse is that these drugs have enhanced rewarding effects when taken together. The goal of this work was to use the conditioned place preference (CPP) procedure to determine whether @entity1239 would enhance the development of @entity167 -induced CPP. METHODS: The conditioned rewarding effects of @entity1239 (1 or 2  mg/kg of @entity1239 tartrate), @entity167 (1  g/kg), and @entity1239 plus @entity167 in combination were assessed using a well-established CPP procedure chosen specifically for examining alterations in the development of @entity167 -induced CPP by @entity1239 . In addition, the reference dose procedure was used to directly compare the conditioned rewarding effect of @entity167 versus @entity1239 plus @entity167 . DBA/2J @entity19 were used because they are an inbred strain that has repeatedly been shown to develop CPP to @entity167 . RESULTS: Neither dose of @entity1239 alone produced CPP, whereas @entity167 did, using the standard @entity167 CPP procedure. The magnitude of @entity167 -induced CPP was not affected by co-administration of 1  mg/kg @entity1239 , but 2  mg/kg @entity1239 interfered with the development of @entity167 -induced CPP. Using the reference dose procedure, there was no significant preference or aversion for either @entity1239  +  @entity167 dose combination versus @entity167 alone. However, combined @entity1239 and @entity167 had a larger effect on locomotor activity, during the conditioning trials, compared to their additive effect when given alone, consistent with previous data. CONCLUSIONS: These data do not support the hypothesis that @entity1239 enhances the conditioned rewarding effect of @entity167 . This finding differs from the combined locomotor stimulant effects of @entity1239 and @entity167 that were observed in this study and in our previously published work, and suggests that combined stimulant effects of @entity1239 and @entity167 do not predict enhanced reward.
