Critical role for glucocorticoid receptors in stress- and XXXX -induced locomotor sensitization.

@entity935 @entity19 @entity167 @entity2819 @entity1068 @entity4944 @entity3927 @entity734
Locomotor sensitization, the augmentation of the locomotor-activating effects of stimuli with repeated exposure, is being evaluated as a partial model for several phenomena including @entity734 . Alteration of dopaminergic systems has been found in sensitized animals and @entity935 neurotransmission appears to be crucial for the expression of sensitized behaviors. However, stress hormones, which are released after exposure to many of the stimuli that produce sensitization, may also be involved in the development of this phenomenon. @entity2819 appears to be important in the development of @entity4944 sensitization and glucocorticoid receptors (GR) have been hypothesized to mediate this effect. The purpose of these experiments was first, to determine whether repeated restraint stress sensitizes DBA/2J @entity19 to the activating effect of @entity1068 ( @entity167 ), and second, to explore the role of GR in stress- and @entity167 -induced sensitization with the GR antagonist, @entity3927 . This antagonist was administered before restraint or i.p. @entity167 (1.5 g/kg) on each of 10 consecutive days of pretreatment. In addition, plasma @entity2819 levels were determined at various points throughout the pretreatment period and on test days. The results demonstrated that 10 consecutive days of 2-hr restraint sensitized @entity19 to @entity167 's locomotor-stimulating effect. Both stress- and @entity167 -induced sensitization were attenuated by administration of @entity3927 during the pretreatment phase.(ABSTRACT TRUNCATED AT 250 WORDS)
